95 Grand Am 3.1 - temperature issues

1995 Grand Am - 3.1L V6, approx 124K.

Recently we had to replace the heater core on this car. Since then I've noticed that the temp rises at extended stops to about 220+. Also the car seems to surge.

My wife told me this evening that the low coolant light briefly illuminated and sure enough it's low. No milkshake in the oil, and nothing on the ground. I popped the hood and heard some gurrgling coming from the reservoir tank.

Any ideas? Would bleeding the system and/or replacing the thermostat do any good? And while I'm asking, where is the thermostat located?

Thanks.

Yes you need to bleed the cooling system it has air pockets.

theres a sensor in the side of your radiater. that makes it go off it'll say low coolent might not everytime but if it's real bad it will.and the 3.1 or 3100 had problems with head gasket belive me i got one.

yes it sounds like an air pocket trapped in the cooling system.

Check your coolant level when the coolants cold and make sure its not going empty when it gets warmed up.
It will also help to drive with the heater on to cycle thru the h core, which is where the air likes to get trapped.

yep, sounds like you need to burp that thing!

I'll burp the baby tomorrow and post to see if it works. Thanks everyone.

My wife brought the car to Goodyear yesterday (they are the ones who replaced the Heater Core), they bled the system and confirmed that there was air in the system. So far so good.

Back again:

I drove the car to work this morning, and at the first light the temp was up past 240 degrees. After I got going again the temp almost redlined and then took a dip back down to below the 220 line. Then the same thing happened at the next stop light. I turned on the heater and that seemed to help and it the temp stayed below the 220 line for the rest of the commute. My co-worker seems to think that it's a bad thermostat. If that's the case where is it located?

3.1 V6

Thanks.

I was able to bleed some more air out of the system. We ran the car for a while to get it nice and warm and at around 230-240 the fan kicked on and brought her back down to normal.

but now I've got an SES light!!!

I wouldnt worry much about the SES if its running alright.

It can take some time to get all the air out of the system, much much longer then it should! :disappoin
I noticed my GT was gurggling the other night from the heater core, and I'd replaced the head and LI gaskets well over a month ago. I think I might have let it get low on coolant. :)

I would keep an eye on the coolant level! Try not to let it go empty or it'll suck more air back into the system.

If the thermostat was bad it would most likly stick and the temps would either stay high or could be to low.
The extreme flucuations are from the air, the coolant has a hard time pumping an air pocket, as it was designed to pump fluids, which causes brief temp spikes. At least you know your fans are working ! :thumbsup:

More then anything, IMO its a bad cooling system design. :2cents:

Good to know X. I'm going to bring it home, cool it off, fill up the res. tank and then try to bleed it a little more. Thanks.

No problem !
Thier is also a procedure in the Tips and Maintenance section, here is the link if you havnt seen/read that.
Bleeding Your Cooling System (http://www.automotiveforums.com/vbulletin/showthread.php?t=718130)

i agree on the rest of the air you think you still have in that line will go away soon.if you can fit your foot under the brake when it's started it should be ok.

ok your top radiator hose leads right to the thermostat at other end of hose.