Are there any 'issues' that are real gotchas with the 3.1L motor
in the Gran Prix?
I remember someone saying something about a plastic intake
manifold and coolant, but I don't know if that was referring to this
motor or not.
My Gran Prix occasionally would show a high temp spike when
I started it and first time of the day, but would otherwise be fine.
Last week the car sat for 7 days, and when I drove it, the spike
happened and it DIDN'T come down. It also had no heat, which
never seemed to happen before either.
I think I caught it in time, but I won't have a chance to look at it for
perhaps another 5 days.
The 3.1L suffers from intake manifold gaskets problems, not the plenum
problems you make reference to. The plenum problems are unique to the 3.8L.
Your description sounds like a car low on antifreeze. If you get too low
you won't build up the required pressure in the system, and you won't get
heat, but the engine will overheat. Check your coolant level before you do
anything else. Faulty radiator caps, plugged heater cores and other things
can also cause a no-heat problem, but the most likely is low coolant.
Hmm, posted once, but it never appeared...
You're right, low coolant. It all drained into the oil pan! A local
mechanic friend is looking at it right, and so far he's 99% sure it's
the gasket. He said I should have the car back tonight.
He's putting in a metal part. He's had to do a few with the
original GM part more than once. Makes me wonder if there's
also a tolerance/alignment issue. But he now get a metal gasket
and he said he's never had to do one again once he puts that in.
I don't know if it's a revised GM part or aftermarket.
I hadn't driven the car for about 9 days. I had carpooled for 3
days to my job at the mountain (skiing) then went on a ski trip
for 5 days. As a result, the car sat and 'cooled down' for more
than 2 days for the first time in the last 5 years or so.
For quite some time there were 'hints'. I'd get a 'sludge' under the EGR
solenoids that I couldn't track down, so I think the gasket was cracked
and leaking a bit for some time. However, the car ran fine.
Thanks for the info.
Just as a follow-up for the group...
For the last number of months, I was getting 'Service Engine' with
EGR problems. This was minor, and I could make it go away
(for a while) by just pulling the 3-way EGR assembly off and
cleaning out this 'goo' that was in there. Even at it's worst though,
the engine light would be variable, from 10 miles into a trip to 60
miles into a trip, and always when I was decelerating.
Anyway, I went away for a ski trip and the car sat for 9 days in
sub-freezing temps. At one point below zero.
Came back, and 3 miles into the first run the temp gauge skyrocketed.
I let it cool and then spurted and coasted it home.
Plastic intake manifold gasket seal thingie. (Engine has 120K on it)
So, off to the shop. A new metal assembly installed ( to hell with
that plastic thing that originally came on the motor ) and a lot of
cleaning. Then fill with old used oil and a used filter, run to warm
and drain. Do it again. Drain. Then another used filter and engine
flush. Drain. Then yet another oil fill and drain. And finally new
filter, new oil, and check it out and drive it. Seems to be fine now.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.