Dave 29

Hey guys this is a very informative forum.
This is my first post I need info on chaning my thermostat in a 1995 Grand Prix 3.1 litre engine. Has air and fuel injection.
What all do I have to remove to change the thermostat?
any good info with pictures anywhere?
I can take digital pics of mine if needed thanks for any info
Dave
dwal@rogers.com

kustomkid54

Dave,
Have the information on 97 and above.
Best I can tell you is follow the top radiator hose back. Remove two bolts on neck. Clean off old gasket. and install.
Sorry.

Dave 29

thanks for the quick reply, doesnt look that easy on this one, I swear I chaned a thermostat before and it was only 2 bolts...this one looks like its on the side under all kinds of air intake hoses and fuel lines etc...
Dave

kustomkid54

Can't help you with that one. Can't find anything on the 95. In 95 I had a Seville.

Dave 29

anyone else?

Chazman

I'm tempted to put in my two bits, but my 3.1 is in my 94 grand am.

Is the thermostat below the throttle body on yours ?

Dave 29

I believe so, its on the side too not on top.
Dave

Chazman

I was trying to post a picture of mine, but was unable.

If it is the same, it shouldn't be to much trouble.

Remove the air filter and the big black hose that goes to the intake.

The thermostat housing is pretty tight to the exhaust, but on mine the houseing has a cut out next to the rear bolt - therefore you should not have to remove this bolt completly, just loosen it.

The gasket is somewhat like a rubber oring, it fits on the thermostat before installation - you shouldn't have to scrape this one of, maybe a bit of corrosion if anything.

Dave 29

I removed the air filter housing and black hose etc...
still cant get a socket on the 2 bolts, they are blocked by the manifold and a steel bar above it with no cutouts, tried a swivel still no luck.
anyone know what size the bolts are?
13mm I think...
help!
Dave

Dave 29

I got the front bolt off but no way can I access the rear bolt without removing some fuel lines and the throttle body or the manifold which seems ridiculous to me to change a thermostat...
Its 13 mm but I cant find a wrench long enough to get torque on it, Ill have to shop around more...
I cant get a socket on it at all..I can get a closed end bycycle wrench? I think you call them on it but not enough leverage to start it...
thanks for any tips or info...
Dave

Chazman

Put your box end 13 mil. wrench on the bolt, then take anouther wrench and hook its box end into the open end of the 13 mil. This should double the length of your wrench and give you the torque you need.

If you don't understand what I mean let me know, and I will e-mail you a picture.

Dave 29

thanks for the help. I got the 2 bolts off using your method...
but its so damn tight against the manifold I had a hell of a time getting the thermostat assembly out since the thermostat was stuck inside it....
anyway got it out and back in but now I cant start that back bolt...argh..can we swear on here? lol
Ill get it eventually but it sure is a tight fit and a bad design if you ask me..
thanks again Chazman !
Dave

Chazman

NP, glad I could help, can you get a shorter bolt ?

Just remember - if it was easy, anybody could do it !!!

Dave 29

Chazman and Kustomkid thanks alot for the help, I got it done this morning.
I had it done last night but the thermostat housing was leaking a bit so I had to lossen it and slide it down over the back bolt a bit better and get more torque on it, it seems fine now and heater is working great.
anything I should watch out for? other than leaks ...how do I know if I got the air out of the system?
anyway my hands are cut bruised and a bit swollen it was real hard to get the wrenches down under the fuel lines and manifold but I didnt want to remove all that stuff.
hopefully I got it working right now..now to fix the abs light on and the engine light just came on in our 99 Windstar van here we go again lol...
Dave

Chazman

Your 3.1 liter should have an air bleader screw were the heater core pipe comes out of the top of the water pump (front of the motor passenger side.)

Wait for the system to build up pressure, with the rad cap on, then loosen the bleeder screw but do not remove it, wait until only a steady stream of coolant comes out, close the bleeder and repeat until all air has been purged.

Keep an eye on the temp. gauge for the first couple of days.

Abs light ? might want to check the condition of your brake pads or shoes.