Valve guide oil seal question...
Tegger
worn main bearings. However...
Is it possible for worn valve guide oil seals to contribute to high oil
usage but NOT result in a puff of smoke out the taipipe from a cold start?
Or will worn valve guide oil seals ALWAYS evidence smoke puffs on cold
startup?
--
Tegger
*
Tegger <teg...@tegger.c0m> wrote in article
<Xns99A669AF...@207.14.116.130>...
Worn main bearings will NOT cause high oil consumption.......worn valve
guiides WILL.....and they don't always result in a puff of smoke on
startup.
Conversely, a puff of smoke on startup usually IS the result of worn
guides.
Dan_Thom...@yahoo.com
Yes, it will. Worn bearings result in more oil going through them
and this oil gets thrown around in the case. Too much lands on the
cylinder walls and floods them, and the oil rings begin to float on it
rather than scraping it off. It's a real problem in truck and heavy
equipment compressors, where the oil doesn't get burned as it does in
the engines, and ends up in the air system where it causes lots of
trouble. I was in the compressor rebuilding industry for a long time
and found that the best way to make a compressor run dry enough to
please the customer was to get those bearing clearances down to the
manufacturer's minimum spec. They're every bit as important as the
ring gaps and piston clearances.
Dan
hls
"Tegger" <teg...@tegger.c0m> wrote in message
> Or will worn valve guide oil seals ALWAYS evidence smoke puffs on cold
> startup?
Worn (or decomposed) valve guide seals dont always tattle with a puff of
smoke on a cold start. Depends on the engine itself and design, as well as
the degree of oil leakage.
But they OFTEN betray the problem by the blue oil smoke puff on cold
startup.
I have had cars that behaved like they had worn seals, but really never used
any significant oil.
A friend of mine had a Honda that ate the seals after he drove the car on
the
Autobahn and overheated it. It began to use oil. We pulled the rubber
seals
and they crumbled like popcorn. Replacing them fixed the problem - for a
while.
It is my belief, and I am sure it will be challenged, that most oil
consumption
problems either stem from leaks, or from worn oil control rings/cylinder
wall
issues.
gfulton
<Dan_Thom...@yahoo.com> wrote in message
news:1189350620.7...@r34g2000hsd.googlegroups.com...
Correct. And was the answer to one of the questions on my A&P FAA mechanics
exam 33 years ago. Too much oil leakage from around the mains will sling
up into the cylinders and overcome the rings' capacity to control it.
Garrett Fulton
Tegger
news:7c80c$46e4a87e$438cff77$15...@ALLTEL.NET:
The consensus then is that worn valve stem oil seals are NOT a significant
factor in oil consumption?
And if worn bearings were present, would that also coincide with the
tendency of the oil light to come on at idle when the oil was hot?
--
Tegger
gfulton
"Tegger" <teg...@tegger.c0m> wrote in message
If the main bearing were so loose to be leaking enough oil to drop pressure
low enough to turn on the oil light, I'd think you'd have to hear some
thumping from the bottom end. My son rebuilt a 400 small block Chevy a
while back, and when adjusting the hyd. lifters, (first time he'd ever done
it), got them way too tight and wiped off most of several of the cam lobes.
Contaminated the oil with metal big time, chewed up the main journals and
bearings to the point that oil pressure went way down at idle. No light on
this El Camino, a guage. But you could definitely hear the bottom end
hammering away, and loud. Just my .02, but I'd sure think you could hear
noise from the bottom end if they were that far gone. And yes, it was sure
an expensive mistake for Dad, but we went ahead and tore it completely down
and rebuilt it again. Had to have another crank.
Garrett
Tegger
news:_OXEi.53181$YL5....@newssvr29.news.prodigy.net:
>
> It is my belief, and I am sure it will be challenged, that most oil
> consumption problems either stem from leaks, or from worn oil control
> rings/cylinder wall issues.
>
>
>
That's my thinking too, but I wanted input from the knowledgeable people
here.
I've been told that worn valve guide oil seals can cause excessive oil
consumption in-and-of themselves, while at the same time NOT causing a puff
of smoke on startup.
--
Tegger
Steve
Worn out valve stem seals usually create a puff of smoke on acceleration
after prolonged idling. On a cold start, the exhaust system is generally
cold enough that you don't get the puff of smoke.
Steve
>>Worn main bearings will NOT cause high oil consumption...
>
>
> Yes, it will. Worn bearings result in more oil going through them
> and this oil gets thrown around in the case. Too much lands on the
> cylinder walls and floods them, and the oil rings begin to float on it
> rather than scraping it off.
ONLY if the rings themselves are also shot. Whenever I build an engine,
I increase the flow out of the oil squirt holes on the connecting rods
to deliberately increase oil flow to the underside of the piston and the
cylinder walls, and good oil control rings have no problem contending
with the added oil. Same for turbo engines with piston oil squirters
from the factory.
N8N
> "gfulton" <lbful...@alltel.net> wrote innews:7c80c$46e4a87e$438cff77$15...@ALLTEL.NET:
>
>
>
>
>
>
>
> > <Dan_Thomas_nos...@yahoo.com> wrote in message
> >news:1189350620.7...@r34g2000hsd.googlegroups.com...
> >>> Worn main bearings will NOT cause high oil consumption...
>
> >> Yes, it will. Worn bearings result in more oil going through them
> >> and this oil gets thrown around in the case. Too much lands on the
> >> cylinder walls and floods them, and the oil rings begin to float on
> >> it rather than scraping it off. It's a real problem in truck and
> >> heavy equipment compressors, where the oil doesn't get burned as it
> >> does in the engines, and ends up in the air system where it causes
> >> lots of trouble. I was in the compressor rebuilding industry for a
> >> long time and found that the best way to make a compressor run dry
> >> enough to please the customer was to get those bearing clearances
> >> down to the manufacturer's minimum spec. They're every bit as
> >> important as the ring gaps and piston clearances.
>
> >> Dan
>
> > Correct. And was the answer to one of the questions on my A&P FAA
> > mechanics exam 33 years ago. Too much oil leakage from around the
> > mains will sling up into the cylinders and overcome the rings'
> > capacity to control it.
>
> > Garrett Fulton
>
> The consensus then is that worn valve stem oil seals are NOT a significant
> factor in oil consumption?
eh, I don't know if I would go that far; they certainly can
contribute.
>
> And if worn bearings were present, would that also coincide with the
> tendency of the oil light to come on at idle when the oil was hot?
>
Absolutely. whereas valve guide seals have nothing to do with oil
pressure, but an oil light at idle is an indication that *some*
clearance is out of spec - either main, rod, or cam bearings, or maybe
lifter-to-bore or rocker-to-shaft clearances (if applicable) or most
likely a stackup of ALL clearances having worn to their wear limit or
close to it, and the cumulative effect is a below-spec idle oil
pressure.
Now I have no idea what kind of engine you're talking about here, but
a common issue with Studebaker V-8s (I know, suddenly it's 1950) is a
combination of excessive oil flow to the rockers combined with old,
hardened valve seals, which results in a really smoky exhaust after a
quick blast at high RPM or hard cornering. Most people install Teflon
scraper style valve seals to "solve" this problem when the real fix is
to restrict the oil flow to the rocker shafts (and simply replace the
valve seals with new stock type.)
nate
ranto...@mail.com
Tegger wrote:
>The consensus then is that worn valve stem oil seals are NOT a significant
>factor in oil consumption?
Not according to owners of pre-1984-1981 VW Rabbits, Sciroccos, and
Jettas. VW first told owners it was perfectly normal to burn as much
as a quart of oil every 200 miles, but the EPA disagreed and forced an
emissions recall where Teflon valve seals were installed. My Rabbit
was burning a quart every 600 miles by the time I received my recall
notice, but it never smoked visibly.
ray
>>The consensus then is that worn valve stem oil seals are NOT a significant
>>factor in oil consumption?
>
>
I'm going to hijack this thread - is it worn valve seals or guides that
give that puff of blue when you start your truck for the first time
after it's been sitting for a week? Or is that rings?
(1990 Chev 1/2 ton 350 with ~200k miles)
Ray
John S.
> I know that the primary causes of high oil consumption are worn
> rings
And valve seals are another cause of high oil consumption.
> or
> worn main bearings. However...
> Is it possible for worn valve guide oil seals to contribute to high oil
> usage but NOT result in a puff of smoke out the taipipe from a cold start?
A little bit of oil can make a lot of smoke.
> Or will worn valve guide oil seals ALWAYS evidence smoke puffs on cold
> startup?
Always and never are always known to never happen.
But worn valve seals usually do exhibit that behaviour.
- Hide quoted text -
- Show quoted text -
Nate Nagel
any and all, but if it does not smoke while running but does on startup
my money's on a combination of guides and seals. Likewise if it starts
smoking again under high vacuum conditions (i.e. throttle closed,
coasting down a hill)
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
sdlomi2
"Tegger" <teg...@tegger.c0m> wrote in message
Hey, Tegger, I read all the responses and was afraid something important
was gonna be missed, but it was finally covered--by John S. Main bearing
wear does cause high oil "loss" esp. on certain engines, Chev V-8
small-block for ex., when they wear (and it doesn't take all that much) and
let the crank fall down and "wallop" the rear main seal so as to cause too
much clearance around the crank. Can cause high oil "leakage", which
results in high oil "consumption". Thanks, John S, for mentioning that
unkind scenario. s
Dan_Thom...@yahoo.com
The squirt hole gives only the briefest squirt, when it
passes the crank's gallery, regardless of its size. Loose bearings
throw a lot of oil, all the way around the cycle. I did hours of dyno
tests on compressors, with cylinders rebored and brand new pistons and
rings all held to tightest specs, and with looser bearing clearances
they passed a lot more oil into the chamber. These compressors are
built exactly like engines: cast iron blocks, aluminum pistons, and
cast/stainless rail rings. The dyno testing allows the compressor to
run with the head off, and it's easy to see that the rings are
hydroplaning on the excessive oil.
If it applies for compressors and for aircraft engines, it
applies for autos. The rings are limited in how much oil they can
control. When any compressor failed for lack of oil supply, it was
always the bearings that went first. Every time. The cylinders need a
tiny fraction of what the bearings need. Throwing more oil into the
cylinder accomplishes nothing. In opposed-cylinder aircraft engines,
the oil squirt hole is intended to cool the underside of the piston
opposite.
Hastings, the piston ring people, have this to say about
it:
"Bearing clearances determine how much oil is "spun off" by
the rotating crankshaft some of that is deposited on the bottom end of
the cylinders. If the oil film thickness from the "spun off' oil
becomes too thick the piston rings will hydroplane on the oil film.
This oil will migrate to the combustion chamber to be burned."
The website that this came from is here:
http://www.hastingsmanufacturing.com/ServiceTips/factors_influencing_oil_control.htm
These guys also say it: http://www.canadiandriver.com/articles/jk/050608.htm
"Worn piston rings and cylinder walls allow oil past the
piston into the combustion chamber. Oil is thrown onto the cylinder
walls from the crankshaft bearings so large bearing clearances can
also cause oil consumption because there is too much oil on the
cylinder wall for the rings to control."
Argue with the experts if you like.
Dan
Dan_Thom...@yahoo.com
I should have also made the point that turboed engines use a lot
less oil because there isn't usually much negative pressure in the
cylinder, except at idle. The boost pressure keeps the oil down.
Turboing compressors on trucks and heavy equipment does the same
thing.
Dan
ray
> ray wrote:
>>>>
>>>> The consensus then is that worn valve stem oil seals are NOT a
>>>> significant
>>>> factor in oil consumption?
>>>
>>>
>>>
>>
>> I'm going to hijack this thread - is it worn valve seals or guides
>> that give that puff of blue when you start your truck for the first
>> time after it's been sitting for a week? Or is that rings?
>>
>> (1990 Chev 1/2 ton 350 with ~200k miles)
>>
>> Ray
>
> any and all, but if it does not smoke while running but does on startup
> my money's on a combination of guides and seals. Likewise if it starts
> smoking again under high vacuum conditions (i.e. throttle closed,
> coasting down a hill)
>
> nate
>
thanks.
It's just a puff once in a while when starting. No noticeable smoke any
other time.
I figure it'll probably be rebuild time in the next couple of years -
it's just a smallblock and I've got lots of parts for those with the
race car... (including a late 80's 305 and 350 with the same type of
heads and crank as on the truck - it's the centrebolt valve cover style
but not vortec heads...)
Ray
Steve B.
>
> Yes, it will. Worn bearings result in more oil going through them
> and this oil gets thrown around in the case. Too much lands on the
> cylinder walls and floods them, and the oil rings begin to float on it
> rather than scraping it off.
>
I never heard this before. Thanx for the info. It's only 12:48 and I
already learned something new for the day. Guess that means I get to
screw off until tomorrow :-)
Steve B.
*
Dan_Thom...@yahoo.com wrote in article
<1189350620.7...@r34g2000hsd.googlegroups.com>...
> > Worn main bearings will NOT cause high oil consumption...
>
> Yes, it will. Worn bearings result in more oil going through them
> and this oil gets thrown around in the case. Too much lands on the
> cylinder walls and floods them, and the oil rings begin to float on it
> rather than scraping it off.
You just might want to drop a line to the Chevrolet engineers who have just
introduced the replacement for the SB-2 engine block. They're probably in
for a rude awakening based on what you say, and what they have done.
At the base of each cylinder on the new block are squirters that squirt oil
up onto the cylinder wall and underside of the piston.
NASCAR Cup engine builders have been building their own lower cylinder
oiling rigs for years from copper tubing and brass fittings, so Chevrolet
simply cast it into the oil galley for them.
>It's a real problem in truck and heavy
> equipment compressors, where the oil doesn't get burned as it does in
> the engines, and ends up in the air system where it causes lots of
> trouble.
I realize that engines are often referred to as simply being "air pumps",
but there are some significant differences between an engine and a
compressor.
> I was in the compressor rebuilding industry for a long time
> and found that the best way to make a compressor run dry enough to
> please the customer was to get those bearing clearances down to the
> manufacturer's minimum spec. They're every bit as important as the
> ring gaps and piston clearances.
>
.....in an air compressor, maybe.....but, not in an engine.
If you are burning oil due to excessive oil being splashed onto the
cylinder walls, then you have a ring problem.
*
----------
> From: Dan_Thom...@yahoo.com
> Newsgroups: rec.autos.tech
> Subject: Re: Valve guide oil seal question...
> Date: Monday, September 10, 2007 7:35 PM
>
> I did hours of dyno
> tests on compressors, with cylinders rebored and brand new pistons and
> rings all held to tightest specs, and with looser bearing clearances
> they passed a lot more oil into the chamber. These compressors are
> built exactly like engines: cast iron blocks, aluminum pistons, and
> cast/stainless rail rings. The dyno testing allows the compressor to
> run with the head off, and it's easy to see that the rings are
> hydroplaning on the excessive oil.
>
That's NOT real-world conditions. How many compressors actually run with
the head off and no cylinder pressures?
Cylinder pressures assist in seating rings.
> If it applies for compressors and for aircraft engines, it
> applies for autos. The rings are limited in how much oil they can
> control. When any compressor failed for lack of oil supply, it was
> always the bearings that went first. Every time. The cylinders need a
> tiny fraction of what the bearings need. Throwing more oil into the
> cylinder accomplishes nothing. In opposed-cylinder aircraft engines,
> the oil squirt hole is intended to cool the underside of the piston
> opposite.
>
See my post in this thread about the new racing block developed by
Chevrolet.....They are squirting additional oil onto the lower
cylinders....
>
> Argue with the experts if you like.
> Dan
>
>
Yup!
Go argue with the engineers at Chevrolet......
Steve
> On Sep 10, 9:27 am, Steve <n...@spam.thanks> wrote:
>
>>Dan_Thomas_nos...@yahoo.com wrote:
>>
>>>>Worn main bearings will NOT cause high oil consumption...
>>
>>> Yes, it will. Worn bearings result in more oil going through them
>>>and this oil gets thrown around in the case. Too much lands on the
>>>cylinder walls and floods them, and the oil rings begin to float on it
>>>rather than scraping it off.
>>
>>ONLY if the rings themselves are also shot. Whenever I build an engine,
>>I increase the flow out of the oil squirt holes on the connecting rods
>>to deliberately increase oil flow to the underside of the piston and the
>>cylinder walls, and good oil control rings have no problem contending
>>with the added oil. Same for turbo engines with piston oil squirters
>>from the factory.
>
>
> I should have also made the point that turboed engines use a lot
> less oil because there isn't usually much negative pressure in the
> cylinder, except at idle.
Turbocharged gasoline engines do NOT run under boost under normal,
steady-state cruising. Diesls, do, but not gas turbos.
Steve
> On Sep 10, 9:27 am, Steve <n...@spam.thanks> wrote:
>
>>Dan_Thomas_nos...@yahoo.com wrote:
>>
>>>>Worn main bearings will NOT cause high oil consumption...
>>
>>> Yes, it will. Worn bearings result in more oil going through them
>>>and this oil gets thrown around in the case. Too much lands on the
>>>cylinder walls and floods them, and the oil rings begin to float on it
>>>rather than scraping it off.
>>
>>ONLY if the rings themselves are also shot. Whenever I build an engine,
>>I increase the flow out of the oil squirt holes on the connecting rods
>>to deliberately increase oil flow to the underside of the piston and the
>>cylinder walls, and good oil control rings have no problem contending
>>with the added oil. Same for turbo engines with piston oil squirters
>>from the factory.
>
>
> The squirt hole gives only the briefest squirt, when it
> passes the crank's gallery, regardless of its size. Loose bearings
> throw a lot of oil, all the way around the cycle.
But they only throw oil AT the cylinders for about the same brief
interval that the squirt-hole does.
I did hours of dyno
> tests on compressors, with cylinders rebored and brand new pistons and
> rings all held to tightest specs, and with looser bearing clearances
> they passed a lot more oil into the chamber. These compressors are
> built exactly like engines: cast iron blocks, aluminum pistons, and
> cast/stainless rail rings. The dyno testing allows the compressor to
> run with the head off, and it's easy to see that the rings are
> hydroplaning on the excessive oil.
You can equate a compressor to an engine if you want, I would argue that
despite the similarities there are enough differences (lack of
combustion pressure being merely one example) to call the comparison
into question.
> If it applies for compressors and for aircraft engines, it
> applies for autos. The rings are limited in how much oil they can
> control.
I don't disagree, but the DIFFERENCE in the amount of oil put on the
cylinder walls by slightly worn bearings versus the normal squirters is
NOT sufficient to cause an increase in consumption, provided that the
oil scraper ring is still in good shape.
Dan_Thom...@yahoo.com
In aircraft gasoline engines, the turbo is loading anytime
the engine is above about 1400 RPM.
Dan
MG
<ranto...@mail.com> wrote in message
news:1189449456.9...@57g2000hsv.googlegroups.com...
cheapest stuff I could find at the drugstore. It wasn't in there long
enough to matter. The question was always which I would have to ad first,
oil or gas. I even got it fixed one time and about 20k miles later, same
thing.
--
Posted via a free Usenet account from http://www.teranews.com
Steve W.
> Tegger <teg...@tegger.c0m> wrote in
> news:Xns99A669AF...@207.14.116.130:
>> I know that the primary causes of high oil consumption are worn rings
>> or worn main bearings. However...
>>
>> Is it possible for worn valve guide oil seals to contribute to high
>> oil usage but NOT result in a puff of smoke out the taipipe from a
>> cold start?
>>
>> Or will worn valve guide oil seals ALWAYS evidence smoke puffs on cold
>> startup?
>>
>
>
> reply to my original post.
>
> The reason I asked the original question has to do with a weird observation
> with my engine, which happens to be a Honda product and has almost 300K
> miles. I change my oil every 2500 miles without fail, and have done so
> since the warranty ran out in 1994.
>
> For the longest time the engine used no oil that I could see. Then suddenly
> it started using oil at about the rate of 2500 miles per quart. It stayed
> this way for several years. Then summer 2006 it dropped precipitously, to
> about 1500 mi/qt, and as low as 1200 mi/qt at the very height of summer.
>
> The car does NOT leak oil, so it's surely being burned.
>
> I tried different viscosities, different brands, in an attempt to improve
> matters. Even tried Mobil-1 0W-40. Nothing I tried had any effect of any
> kind on consumption.
>
> But now, about a year or so later, my consumption has DECREASED. It's now
> running at around 1800 mi/qt. My measuring method is very precise, so I
> know these are accurate numbers.
>
> Other than something to do with valve guide oil seals, I cannot fathom how
> this engine is burning LESS oil than it was a year ago. WTF is going on?
>
> I considered fuel in the oil, but the oil doesn't smell like it has
> significant gas in it, and my fuel mileage has remained steady for more
> than a decade (28-30mpg). The car is driven great distances at a time, so
> it can't be water building up.
>
> Thoughts, anyone?
>
If the oil consumption increased that much, rapidly, then something
broke. My guess would be that an oil ring expander collapsed. That would
allow more oil burning. Then as the oil burned carbon started to build
up and that slowly caused the ring groove to fill with carbon to the
point it acted like an oil control ring.
Some more oil being drawn past worn guides and seals and your burning oil.
If you want to find out do a leak down test on each cylinder.
--
Steve W.
Tegger
news:Xns99A8C9E1...@207.14.116.130:
> My measuring method is very precise,
> so I know these are accurate numbers.
In case there is anyone actually interested in my "very precise" measuring
method...
My engine's dipstick spans 14mm between upper and lower marks. This 14mm
span represents one liter, or about 1.057 US quarts.
I printed out an accurate scale showing the 14mm span. marking the
millimeters.
1) Change oil and filter.
2) Drive car at least a half-hour, so oil is good and hot.
3) Park car in particular location.
4) After car has sat /overnight/, pull dipstick, wipe off, reinsert ALL the
way, record oil level. Measure against millimeter scale to see where level
is relative to upper mark. Repeat a few times to be certain.
5) Drive 1000 miles.
6) Make sure last drive is as per step 2.
7) Repeat Step 3, making sure car is parked exactly the same way as it was
for the first check.
8) Check oil level as Step 4, but placing the upper mark of your scale
where the oil level was the first time you performed Step 4.
9) Calculate consumption.
Example from this last change:
1000 mile level down about 7.5mm from original level. This corresponds to
0.5357 liter, or 0.5661 US quart.
1000/0.5661 = 1766 miles per quart.
--
Tegger
Tegger
> Tegger wrote:
>>
>> Other than something to do with valve guide oil seals, I cannot
>> fathom how this engine is burning LESS oil than it was a year ago.
>> WTF is going on?
>>
>> I considered fuel in the oil, but the oil doesn't smell like it has
>> significant gas in it, and my fuel mileage has remained steady for
>> more than a decade (28-30mpg). The car is driven great distances at a
>> time, so it can't be water building up.
>>
>> Thoughts, anyone?
>>
>
> If the oil consumption increased that much, rapidly, then something
> broke. My guess would be that an oil ring expander collapsed. That
> would allow more oil burning. Then as the oil burned carbon started to
> build up and that slowly caused the ring groove to fill with carbon to
> the point it acted like an oil control ring.
I would never have thought of that.
If carbon is acting as a control ring, is there any harm in just letting it
stay that way?
>
> Some more oil being drawn past worn guides and seals and your burning
> oil.
>
> If you want to find out do a leak down test on each cylinder.
And so I will. What should I expect on the leakdown test?
--
Tegger
ranto...@mail.com
MG wrote:
>
><ranto...@mail.com> wrote in message
>news:1189449456.9...@57g2000hsv.googlegroups.com...
>>
>>Tegger wrote:
>>
>>>The consensus then is that worn valve stem oil seals are NOT a significant
>>>factor in oil consumption?
>>
>>as a quart of oil every 200 miles, but the EPA disagreed and forced an
>>emissions recall where Teflon valve seals were installed. My Rabbit
>>was burning a quart every 600 miles by the time I received my recall
>>notice, but it never smoked visibly.
>>
>Yeah, I had a 75 Rabbit that blew so much oil out that I used to buy the
>cheapest stuff I could find at the drugstore. It wasn't in there long
>enough to matter. The question was always which I would have to ad
>first, oil or gas.
>
received a scolding from a former Caterpillar chemist for just
mentioning it. But I used only high quality major brand oil since it
was usually available somewhere for less than the cost of junk oil.
>
>I even got it fixed one time and about 20k miles later, same thing.
>
valve stem without first covering the groove on the stem with
electrical tape.. The edges of the groove are sharp.
Steve
>>
>>Turbocharged gasoline engines do NOT run under boost under normal,
>>steady-state cruising. Diesls, do, but not gas turbos.
>
>
> In aircraft gasoline engines, the turbo is loading anytime
> the engine is above about 1400 RPM.
>
> Dan
>
Well, I didn't think we were on alt.warbirds ;-)
Steve
> Tegger <teg...@tegger.c0m> wrote in
> news:Xns99A669AF...@207.14.116.130:
>
>
>>I know that the primary causes of high oil consumption are worn rings
>>or worn main bearings. However...
>>
>>Is it possible for worn valve guide oil seals to contribute to high
>>oil usage but NOT result in a puff of smoke out the taipipe from a
>>cold start?
>>
>>Or will worn valve guide oil seals ALWAYS evidence smoke puffs on cold
>>startup?
>>
>
>
>
> So many replies to this thread I don't know where to start. I therefore
> reply to my original post.
>
> The reason I asked the original question has to do with a weird observation
> with my engine, which happens to be a Honda product and has almost 300K
> miles. I change my oil every 2500 miles without fail, and have done so
> since the warranty ran out in 1994.
>
> For the longest time the engine used no oil that I could see. Then suddenly
> it started using oil at about the rate of 2500 miles per quart. It stayed
> this way for several years. Then summer 2006 it dropped precipitously, to
> about 1500 mi/qt, and as low as 1200 mi/qt at the very height of summer.
>
> The car does NOT leak oil, so it's surely being burned.
>
> I tried different viscosities, different brands, in an attempt to improve
> matters. Even tried Mobil-1 0W-40. Nothing I tried had any effect of any
> kind on consumption.
>
> But now, about a year or so later, my consumption has DECREASED. It's now
> running at around 1800 mi/qt. My measuring method is very precise, so I
> know these are accurate numbers.
>
> Other than something to do with valve guide oil seals, I cannot fathom how
> this engine is burning LESS oil than it was a year ago. WTF is going on?
>
> I considered fuel in the oil, but the oil doesn't smell like it has
> significant gas in it, and my fuel mileage has remained steady for more
> than a decade (28-30mpg). The car is driven great distances at a time, so
> it can't be water building up.
>
> Thoughts, anyone?
>
With that much mileage, and with sudden onset, my guess is that you have
broken a couple of rings. Each oil control ring that breaks kicks the
consumption up in a pretty big step. Consumption might go back down a
little as the crack in the ring plugs with some blow-by sludge, but its
hard to say.
MG
<ranto...@mail.com> wrote in message
news:1189596857.3...@50g2000hsm.googlegroups.com...
The oil was whatever the proper API rating was at the time, SE or something,
so I assumed it was reasonably ok. Just not exactly a name brand. My VW
dealer did the repair. This was a huge issue on these particular cars, so
I'm guessing it was more of a design problem than anything else. Don't even
start on the carburetors on those things.
Steve W.
> "Steve W." <ya...@yahoo.com> wrote in news:fc7c51$fjq$1...@aioe.org:
>
>> Tegger wrote:
>
>>> Other than something to do with valve guide oil seals, I cannot
>>> fathom how this engine is burning LESS oil than it was a year ago.
>>> WTF is going on?
>>>
>>> I considered fuel in the oil, but the oil doesn't smell like it has
>>> significant gas in it, and my fuel mileage has remained steady for
>>> more than a decade (28-30mpg). The car is driven great distances at a
>>> time, so it can't be water building up.
>>>
>>> Thoughts, anyone?
>>>
>> If the oil consumption increased that much, rapidly, then something
>> broke. My guess would be that an oil ring expander collapsed. That
>> would allow more oil burning. Then as the oil burned carbon started to
>> build up and that slowly caused the ring groove to fill with carbon to
>> the point it acted like an oil control ring.
>
>
> I would never have thought of that.
>
> If carbon is acting as a control ring, is there any harm in just letting it
> stay that way?
Well with 300K on it, it would depend on what the rest of the vehicle is
like and if you want to spend the money on a rebuild.
>
>
>> Some more oil being drawn past worn guides and seals and your burning
>> oil.
>>
>> If you want to find out do a leak down test on each cylinder.
>
>
> And so I will. What should I expect on the leakdown test?
>
Well with a cold engine you will likely find at least one cylinder
reading higher than the rest. Listen at the oil fill when you are
checking them and you will hear the air going past the rings.
--
Steve W.
Near Cooperstown, New York
Tegger
> Tegger wrote:
>> "Steve W." <ya...@yahoo.com> wrote in news:fc7c51$fjq$1...@aioe.org:
>>
>>> Tegger wrote:
>>
>>>> Other than something to do with valve guide oil seals, I cannot
>>>> fathom how this engine is burning LESS oil than it was a year ago.
>>>> WTF is going on?
>>>>
>>>> I considered fuel in the oil, but the oil doesn't smell like it has
>>>> significant gas in it, and my fuel mileage has remained steady for
>>>> more than a decade (28-30mpg). The car is driven great distances at
>>>> a time, so it can't be water building up.
>>>>
>>>> Thoughts, anyone?
>>>>
>>> If the oil consumption increased that much, rapidly, then something
>>> broke. My guess would be that an oil ring expander collapsed. That
>>> would allow more oil burning. Then as the oil burned carbon started
>>> to build up and that slowly caused the ring groove to fill with
>>> carbon to the point it acted like an oil control ring.
>>
>>
>> I would never have thought of that.
>>
>> If carbon is acting as a control ring, is there any harm in just
>> letting it stay that way?
>
> Well with 300K on it, it would depend on what the rest of the vehicle
> is like and if you want to spend the money on a rebuild.
There's no rust on the body, so fixing the engine is a possibility.
My concern is primarily that a rebuild may not be worth the effort if a
broken ring has damaged the bore. I'm only allowed a .010" overbore.
>
>>
>>
>>> Some more oil being drawn past worn guides and seals and your
>>> burning oil.
>>>
>>> If you want to find out do a leak down test on each cylinder.
>>
>>
>> And so I will. What should I expect on the leakdown test?
>>
>
> Well with a cold engine you will likely find at least one cylinder
> reading higher than the rest. Listen at the oil fill when you are
> checking them and you will hear the air going past the rings.
>
Thanks.
The car runs just fine. It idles quite smoothly and has good power at
all speeds. I'll get the test done at some point, but it's not a panic
right now.
--
Tegger
Steve
> There's no rust on the body, so fixing the engine is a possibility.
>
> My concern is primarily that a rebuild may not be worth the effort if a
> broken ring has damaged the bore. I'm only allowed a .010" overbore.
If you're getting more than 1000 miles per quart, I wouldn't worry too
much about it. Failed oil rings don't usually hurt the bore too much- a
failed COMPRESSION ring will, but you'll KNOW if one of them goes
(sudden drop in power).
Only .010 overbore allowed? Stupid disposable engines. But then,
anything can be sleeved, but it sure does make it less economically
appealing.
Tegger
news:2MmdneSUwedjGXTb...@texas.net:
> Tegger wrote:
>
>
>> There's no rust on the body, so fixing the engine is a possibility.
>>
>> My concern is primarily that a rebuild may not be worth the effort if a
>> broken ring has damaged the bore. I'm only allowed a .010" overbore.
>
>
> If you're getting more than 1000 miles per quart, I wouldn't worry too
> much about it.
That's my thought too. So long as oil consumption and emissions are
manageable, I'm just going to keep on as usual.
> Failed oil rings don't usually hurt the bore too much- a
> failed COMPRESSION ring will, but you'll KNOW if one of them goes
> (sudden drop in power).
>
> Only .010 overbore allowed? Stupid disposable engines. But then,
> anything can be sleeved, but it sure does make it less economically
> appealing.
What Honda did here was to embed a 3mm thick iron sleeve in 3mm of
aluminum. Take too much off the iron and...
I found out (just out of curiosity) that a new Honda short block is about
$3,000 Cdn. With a new head and all related parts, it would cost about
$5,000 to be on-the-road with a brand new engine.
I hope mine goes a few more years.
--
Tegger
hls
"Tegger" <teg...@tegger.c0m> wrote in message
>
> $3,000 Cdn. With a new head and all related parts, it would cost about
> $5,000 to be on-the-road with a brand new engine.
>
> I hope mine goes a few more years.
What would be involved to drive across the border and pick up a good used
engine (if you can find one cheaply enough)? Would you be allowed to bring
it
back and use it, or would taxes and government regulations be the death of
it?
Tegger
news:OVAHi.9740$924....@newssvr23.news.prodigy.net:
Car parts cross the border pound-of-flesh free. Except for shipping...
--
Tegger