cautionary tale
jim beam
when is the last time you checked /your/ valve lash? don't you want to
avoid this little problem?
just pulled this from a civic with "an emissions problem". the
incredible doofus that was ripping the owner off trying to "fix" the
problem, simply welded in a second HUGE catalyst into the exhaust
system. and was disappointed when it didn't work! then they removed
the bulb from the "check engine" light...
Tegger
news:I_mdnaThKsq11obW...@speakeasy.net:
Wow! Nobody noticed the lumpy idle?
I do my valves once a year, which equates to about 25,000 miles. I find
perhaps one or two that have moved maybe a thou. Some years there's no
noticeable change to any of them. I suspect this valve came fom an engine
that may have NEVER had its valved checked.
--
Tegger
The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/
jim beam
> jim beam<m...@privacy.net> wrote in
> news:I_mdnaThKsq11obW...@speakeasy.net:
>
>> http://www.flickr.com/photos/38636024@N00/4162355180/
>>
>> when is the last time you checked /your/ valve lash? don't you want to
>> avoid this little problem?
>>
>> just pulled this from a civic with "an emissions problem". the
>> incredible doofus that was ripping the owner off trying to "fix" the
>> problem, simply welded in a second HUGE catalyst into the exhaust
>> system. and was disappointed when it didn't work! then they removed
>> the bulb from the "check engine" light...
>>
>>
>
>
> Wow! Nobody noticed the lumpy idle?
d15b1 motor - unlike almost all other honda motors, the flywheel is
/really/ heavy - it idled reasonably well. they should have noticed the
lack of difference that plug made when pulling the lead though. a
compression test might have helped too.
initially, i suspected a thrown rod, [classic for "smooth idle"
misfires] but a long screwdriver down the spark plug hole showed the
piston still moving.
>
> I do my valves once a year, which equates to about 25,000 miles. I find
> perhaps one or two that have moved maybe a thou. Some years there's no
> noticeable change to any of them. I suspect this valve came fom an engine
> that may have NEVER had its valved checked.
i suspect it was done, but done badly. should leave the feeler gauge in
when snugging up the lock nut so the adjuster doesn't move.
Nasty
OK. Now you guys have ruined my quiet Sunday morning. Are you saying
that valves should be or MUST be checked on a scheduled basis? Even when
there are no other indications of a valve related problem?
I have 145K on my 2000 Accord that runs smooth as silk. Should I take it
in "just because"?
Greg
>
> I do my valves once a year, which equates to about 25,000 miles. I find
> perhaps one or two that have moved maybe a thou. Some years there's no
> noticeable change to any of them. I suspect this valve came from an engine
> that may have NEVER had its valved checked.
Yea. I check my Accord once a year, more out of guilt than anything
else. I don't expect to find that anything has moved more than a thou.
Even with zero maintenance, you're got to wonder if they abused the
engine somehow. Assuming the valves were set correctly at some time, it
takes a lot of seat wear to eat up the clearance. (Right?)
JRE
I haven't seen a valve that bad since my brother in law pulled in the
driveway with his Fiat just barely able to make it up hills in the early
80's. All four exhaust valves were burned, not because of bad lash, but
because a helpful "mechanic" had removed the air pump belt to give him
more power without bothering to re-jet the carburettor appropriately.
The extremely lean mixture, unleaded fuel, and the non-sodium-filled
valves did the rest. One of the valves was about 40% gone. We were
able to recut the seats without replacing them, but valve height with
new valves was just barely within spec.
The job was an incredible pain in the neck, and led to a "No Fiats" rule
in my driveway that has lasted until this day...I'd sooner replace the
clutch on an Accord on jackstands.
--
JRE
jim beam
> In article<4b1be13b$0$5080$9a6e...@unlimited.newshosting.com>,
> Nasty<na...@tampabay.rr.com> wrote:
>
>> OK. Now you guys have ruined my quiet Sunday morning. Are you saying
>> that valves should be or MUST be checked on a scheduled basis? Even when
>> there are no other indications of a valve related problem?
>>
>> I have 145K on my 2000 Accord that runs smooth as silk. Should I take it
>> in "just because"?
>
> miles. At one time it was 15K miles, but I think yours is 30K miles.
> That is, if it's a 4 cylinder.
>
> My 02 Odyssey specifies to do it "as needed if you hear noise". That's
> marketing speak for "my God, it costs $300 to adjust valves on this
> silly thing! We can't tell them to do THAT every 30K miles!"
how much does it cost for a head gasket replacement? because that's
essentially what you're looking at.
jim beam
it's not just seat wear - the valve heads soften ever so slightly as
they warm up, so extended use at high speed, with the normal hammering
effect of operation, means the seats bash impressions into the head.
that closes clearances quite effectively. you can almost see that in
the pic.
if you're just pottering about town, it's not so much of a problem.
when i used to do more high speed [high temp] runs, my biannual checks
were much more likely to show a need for adjustment.
Tegger
I suppose you could do it that way, but I've been doing valves for almost
30 years and have never left the gauge in.
All I do is to make careful note of the position of the screwdriver slot at
the correct clearance setting, and make a tiny adjustment down to allow for
the slight gain in clearance you get when you snug the nut again.
Tegger
news:elmop-46407D....@nothing.attdns.com:
> In article <4b1be13b$0$5080$9a6e...@unlimited.newshosting.com>,
> Nasty <na...@tampabay.rr.com> wrote:
>
>> OK. Now you guys have ruined my quiet Sunday morning. Are you saying
>> that valves should be or MUST be checked on a scheduled basis? Even
>> when there are no other indications of a valve related problem?
>>
>> I have 145K on my 2000 Accord that runs smooth as silk. Should I take
>> it in "just because"?
>
> The 2000 Accord owner's manual specifies valve adjustment every so
> many miles. At one time it was 15K miles, but I think yours is 30K
> miles. That is, if it's a 4 cylinder.
>
> My 02 Odyssey specifies to do it "as needed if you hear noise".
> That's marketing speak for "my God, it costs $300 to adjust valves on
> this silly thing! We can't tell them to do THAT every 30K miles!"
That's also kind of silly (to my mind) because it's REDUCED valve
clearances that do the big damage. You can't hear reduced clearances.
Tegger
I think it also has a lot to do with oil change intervals. The engine in
question may have had an inadequate frequency of oil changes.
Greg
>> Even with zero maintenance, you're got to wonder if they abused the
>> engine somehow. Assuming the valves were set correctly at some time,
>> it takes a lot of seat wear to eat up the clearance. (Right?)
> I think it also has a lot to do with oil change intervals. The engine in
> question may have had an inadequate frequency of oil changes.
That was my first thought, that the owner had run some additive-free,
buck-a-quart, SA rated oil, or hadn't bothered to change it at all. But
in that case, it seems you'd expect accelerated cam lobe wear that would
tend to open the lash clearance, if anything.
Does the minuscule volume of blow-by oil aid valve seat lubrication in
any way?
Regarding the original picture, I've got to agree with Jim, that lots of
high RPM and/or heat has worn or peened the valve to death. I'd like to
see pics of the seats too.
zzznot
> driveway with his Fiat just barely able to make it up hills in the early
> 80's.
Hey I resemble that remark, sold off my 1971 Fiat circa 1979
in just about that state! Replacedit for with Alfa and drove it until it
ate a (sodium-filled) valve about eight years later.
So far, in my experience, Hondas don't do that!
J.
jim beam
the seats are fine.
the damage you see is not just heat [and definitely not peening], but
actual hot gas erosion. if you've ever used an oxy-acetylene cutting
torch, you'll have created gouges like this in the steel you cut, only
on a larger scale.
bottom line, there are actually two potential causes of this:
1. insufficient valve lash causing leakage, heating and then erosion.
2. defect in the valve - a "soft spot" could start the leakage, and
erosion takes hold from there.
#1 is completely avoidable.
jim beam
well, provided the locking nuts are not crudded up, you can leave the
gauge in and the adjuster won't turn as you tighten the lock nut. makes
it a quick one-handed operation. if there's crud in the threads, you
need the screwdriver and two hands as you say.
Tegger
My valve mechanism is squeaky-clean, with hardly any varnish, let alone
crud. I cannot tighten the locknuts without holding the screwdriver still,
otherwise the adjuster attempts to turn, even with a gauge in the way.
You're putting 18ft/lbs of torque on that locknut, which is sufficient to
push a lot of things around.
jim beam
the patient in the valve surgery case however, is crudded up, and a
screwdriver is essential.
Dillon Pyron
Sure you can. It's that little "tink tink tink" sound of broken metal
bouncing around inside the cylinder.
--
- dillon I am not invalid
I love my country, It's my government I fear.
Hey, turnabout's fair play.
Dillon Pyron
>On 12/06/2009 05:37 AM, Tegger wrote:
>> jim beam<m...@privacy.net> wrote in
>> news:I_mdnaThKsq11obW...@speakeasy.net:
>>
>>> http://www.flickr.com/photos/38636024@N00/4162355180/
>>>
>>> when is the last time you checked /your/ valve lash? don't you want to
>>> avoid this little problem?
>>>
>>> just pulled this from a civic with "an emissions problem". the
>>> incredible doofus that was ripping the owner off trying to "fix" the
>>> problem, simply welded in a second HUGE catalyst into the exhaust
>>> system. and was disappointed when it didn't work! then they removed
>>> the bulb from the "check engine" light...
>>>
>>>
>>
>>
>> Wow! Nobody noticed the lumpy idle?
>
>d15b1 motor - unlike almost all other honda motors, the flywheel is
>/really/ heavy - it idled reasonably well. they should have noticed the
>lack of difference that plug made when pulling the lead though. a
>compression test might have helped too.
>
>initially, i suspected a thrown rod, [classic for "smooth idle"
>misfires] but a long screwdriver down the spark plug hole showed the
>piston still moving.
You said "thrown rod" and my years of drag racing tell me that usually
means a see-through block, or at least an invisible pan.
>
>
>>
>> I do my valves once a year, which equates to about 25,000 miles. I find
>> perhaps one or two that have moved maybe a thou. Some years there's no
>> noticeable change to any of them. I suspect this valve came fom an engine
>> that may have NEVER had its valved checked.
>
>i suspect it was done, but done badly. should leave the feeler gauge in
>when snugging up the lock nut so the adjuster doesn't move.
jim beam
> Thus spake jim beam<m...@privacy.net> :
>
>> On 12/06/2009 05:37 AM, Tegger wrote:
>>> jim beam<m...@privacy.net> wrote in
>>> news:I_mdnaThKsq11obW...@speakeasy.net:
>>>
>>>> http://www.flickr.com/photos/38636024@N00/4162355180/
>>>>
>>>> when is the last time you checked /your/ valve lash? don't you want to
>>>> avoid this little problem?
>>>>
>>>> just pulled this from a civic with "an emissions problem". the
>>>> incredible doofus that was ripping the owner off trying to "fix" the
>>>> problem, simply welded in a second HUGE catalyst into the exhaust
>>>> system. and was disappointed when it didn't work! then they removed
>>>> the bulb from the "check engine" light...
>>>>
>>>>
>>>
>>>
>>> Wow! Nobody noticed the lumpy idle?
>>
>> d15b1 motor - unlike almost all other honda motors, the flywheel is
>> /really/ heavy - it idled reasonably well. they should have noticed the
>> lack of difference that plug made when pulling the lead though. a
>> compression test might have helped too.
>>
>> initially, i suspected a thrown rod, [classic for "smooth idle"
>> misfires] but a long screwdriver down the spark plug hole showed the
>> piston still moving.
>
> You said "thrown rod" and my years of drag racing tell me that usually
> means a see-through block,
usually. but not always - depends how hard the motor was going when the
cap finally let go. i was looking at one in a junk yard just recently.
the head was off and there was no visible external damage to the
block, but one piston was out of phase and rotated. you don't get
/that/ with the rod still connected, regardless of holes.