GM 3.1L V6 coolant temp problem
Kevin J. Phillips
the information that may be necessary...
My wife's car has a coolant temperature issue and I'm hoping to get
some suggestions from you guys. The car is a 1995 Pontiac Grand Am
SE (3.1L V6) w/150K miles. Auto-transmission and A/C.
The coolant temperature gauge has 5 hash marks:
- 100F
- Unlabeled
- 220F
- Unlabeled
- 280F
A few weeks ago, the heater core died, sending coolant all over my
driveway. I had it towed to the shop. They replaced the heater
core and after doing a pressure test reported the radiator was
leaking, so I also had them replace the radiator. Since then the
engine has run hotter than normal. It's not overheating but it is
definitely hotter.
We have had this car since new. Prior to having the work done, the
coolant temp was always around the 2nd hash mark (which I presume
is about 180F-190F), maybe just a tiny bit above it. The only time
I recall it going close to 220F was when I loaded the car down with
a bunch of heavy stuff to take to the dump
Since having the heater core and radiator replaced, the coolant
temperature will go up to 220F (the 3rd hash mark) just while
cruising on the highway at 65 MPH. When street-driving, it runs
cooler than on the highway (but still hotter than before the work
was done); it will vary from the midpoint of the 2nd and 3rd hash
marks, up to 220F. The coolant temp will drop noticably when
accelerating.
I've taken it back to the shop twice. Last week they verified the
system was staying pressurized, that all the air was bled from the
system, and the fan comes on when they are supposed to. Yesterday
they replaced the thermostat (only charging me for the thermostat
itself). I have also verified the front air dam is in place.
The mechanic's position is that since the coolant temperature is
staying below the fan turn-on point (236F?) the cooling system is
operating normally. I disagree with him. Even though the car
isn't overheating, when we're driving on the highway, the coolant
temperature is 220F (30F above the thermostat opening temperature)
and that's not normal.
1st question: Is the mechanic right?
2nd question: If I'm right, any suggestions on what else to look
at? The upper and lower radiator hoses were replaced a few months
ago and the water pump is 2 years old.
Thanks!
LinuxTester
http://www.theherd.com/articles/lt4_temp.html
and (Kool It additive):
http://www.getautohelp.com/automotive_products/96001.html
aarcuda69062
<1146572704....@u72g2000cwu.googlegroups.com>,
"LinuxTester" <mysw...@hotmail.com> wrote:
> check this out (gauge anomaly):
> http://www.theherd.com/articles/lt4_temp.html
Are you suggesting that he has a LT1/LT4 engine in his Grand Am?
> and (Kool It additive):
> http://www.getautohelp.com/automotive_products/96001.html
What if he didn't have Kool-It in his radiator before the heater
core leak?
Kevin
"Kevin J. Phillips" <k...@abs.net> wrote in message
news:YKednRfw4o0_o8rZ...@charm.net...
Verify that the replacement radiator has the same cooling capacity as the
original. Some shops install cheaper radiators with fewer cooling tubes.
They will suffice under normal operation, but you will notice elevated
temperatures under extreme conditions.
--
Kevin Mouton
Automotive Technology Instructor
"If women don't find you handsome, they should at least find you handy"
Red Green
Mike Walsh
Some time ago (probably five or ten years) I flushed the 3.1 engine in my Beretta and added new antifreeze. Afterwards the temperature read considerably different. I don't remember if it was higher or lower, but I thought it was very strange to read differently and I never could figure out why. Also, I replace the thermostat about a year and a half ago and it read about 20 deg.F higher with the new thermostat. The new thermostat starts to open at 205 deg.F (10 degrees higher than specs) and I assume that the old one opened 10 degrees lower than specs.
--
Mike Walsh
West Palm Beach, Florida, U.S.A.
John S.
First off verify with Pontiac what the normal operating temperature
should be.
Next, have someone check the coolant mixture itself. If they used 100%
coolant when it should have been mixed with 50% with water it will not
transfer heat as effectively.
Kevin J. Phillips
> Verify that the replacement radiator has the same cooling capacity as the
> original. Some shops install cheaper radiators with fewer cooling tubes.
> They will suffice under normal operation, but you will notice elevated
> temperatures under extreme conditions.
The shop only installs OEM parts, and I trust them in that respect.
If the radiator wasn't up to snuff, wouldn't I be getting close to
normal temperature on the highway, but overtemp when doing stoplight-
to-stoplight driving?
Kevin J. Phillips
> First off verify with Pontiac what the normal operating temperature
> should be.
Yep, that's definitely a good idea. :-)
> Next, have someone check the coolant mixture itself. If they used 100%
> coolant when it should have been mixed with 50% with water it will not
> transfer heat as effectively.
That's a pretty basic thing to screw up, but I suppose it couldn't
hurt to check it out...
ray
> Since having the heater core and radiator replaced, the coolant
> temperature will go up to 220F (the 3rd hash mark) just while
> cruising on the highway at 65 MPH. When street-driving, it runs
> cooler than on the highway (but still hotter than before the work
> was done); it will vary from the midpoint of the 2nd and 3rd hash
> marks, up to 220F. The coolant temp will drop noticably when
> accelerating.
>
IMHO, hot on the highway but cool around town = airflow problem.
There's nothing jammed in between the rad and the A/C condensor? I've
heard of stuff like plastic bags getting jammed in there.
I would also confirm that they replaced the rad with the right size -
maybe they inadvertently used one for a 4cyl, no AC Grand Am? Double
check the part numbers.
Also, if the thermostat has been changed it could be to blame - the one
in my truck stays closed until it's almost too hot (the needle starts to
go past "normal" and then opens like crazy - the temp drops about 20
degrees and then it slams back shut and cycles like this for a while.)
Nothing wrong with it, I just don't like it.
Lastly... check the connectors for the temperature gauge. A little dirt,
a broken wire... could make your gauge read high.
you're not overheating, but 220 sounds high. On the cars I've owned,
"normal" (aka the middle of the factory gauge) is around 190-210F.
Ray
mst
> In article
> <1146572704....@u72g2000cwu.googlegroups.com>,
> "LinuxTester" <mysw...@hotmail.com> wrote:
>
> > check this out (gauge anomaly):
> > http://www.theherd.com/articles/lt4_temp.html
>
> Are you suggesting that he has a LT1/LT4 engine in his Grand Am?
Not necessarily, but there's nothing with
thinking outside the box.
What was your suggestion to the OP?
> > and (Kool It additive):
> > http://www.getautohelp.com/automotive_products/96001.html
>
> What if he didn't have Kool-It in his radiator before the heater
> core leak?
Again, another option. Also, what is your
suggestion to the OP?
Either participate positively, or dont participate.
--
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Steve
>>Next, have someone check the coolant mixture itself. If they used 100%
>>coolant when it should have been mixed with 50% with water it will not
>>transfer heat as effectively.
>
>
> That's a pretty basic thing to screw up, but I suppose it couldn't
> hurt to check it out...
Its a lot more likely to happen now that we have shelves full of the
idiotic "pre-diluted" antifreeze and people get used to just dumping it
in straight all the time.
aarcuda69062
mst <ms...@linuxMYSHOESmail.org> wrote:
> On Tue, 02 May 2006 12:35:42 GMT aarcuda69062 <none...@sbcglobal.net> wrote:
>
> > In article
> > <1146572704....@u72g2000cwu.googlegroups.com>,
> > "LinuxTester" <mysw...@hotmail.com> wrote:
> >
> > > check this out (gauge anomaly):
> > > http://www.theherd.com/articles/lt4_temp.html
> >
> > Are you suggesting that he has a LT1/LT4 engine in his Grand Am?
>
> Not necessarily, but there's nothing with
> thinking outside the box.
By what stretch is referencing an entirely different engine with
a reverse flow cooling system "thinking outside the box?"
You're comparing horse shoes to pineapples.
> What was your suggestion to the OP?
Had I made one, it certainly wouldn't have anything to do with
relocating the temperature sending units which at best would only
serve to mask whatever problem he's experiencing.
> > > and (Kool It additive):
> > > http://www.getautohelp.com/automotive_products/96001.html
> >
> > What if he didn't have Kool-It in his radiator before the heater
> > core leak?
>
> Again, another option.
Masking the problem is not a very wise option.
If the car didn't need Kool-It jizz in the radiator to function
properly for eleven years, why should it need it now?
> Also, what is your
> suggestion to the OP?
To ignore you.
> Either participate positively, or dont participate.
Who died and made you the boss?
John S.
You might be surprised at how may times that gets screwed up. People
dilute pre-diluted coolant and don't dilute 100% coolant.