Help please Over heating still - '01 Grand Am

tiggerlb

My 2001 Pontiac Grand am will over heat where the red light comes on and then at times it will just run very high temp a few marks before hitting the red line on the temp Gage. My heat blows hot when I am on the express way then it will blow cool on normal roads. When I turn the car off I have coolant spew from the over fill hose on the resivor tank. I have checked for leaks other than it comming out the resivor over fill tank hose there are no other leaks.. It will also boil in the resivor tank at times. My cooling fans do kick on but only when my gage reached about 3/4 of the way up. the air from them seems to be blowing on the motor and not towards the radiator. I have had the car 1 yr and only stated having this problem with overheating. So far I have replaced the thermostst. What else should I look at ? I was thinking temp sensor possible. Thoughts please

ray80

Kind of sounds like it may be low on coolant, have you checked both reservoir and radiator? Are there bleed screws to get air out of system?

Mr_Shiftright

Yes your fan should suck air from the radiator (through the radiator actually, from outside the car) and push towards the engine. So that is working as it should.

Have you inspected/tested the thermostat yet?

imidazol97

tiggerlb said:

My heat blows hot when I am on the express way then it will blow cool on normal roads.

That says to me that you're getting air into the heater core. At low water pump/engine speeds not enough hot coolant is going through. The air could be combustion gases from a head gasket leak or other leak letting
combustion gases into the coolant.

tiggerlb said:

When I turn the car off I have coolant spew from the over fill hose on the resivor tank.

That says it's overheating. So your temperature sensor is not likely the problem.

tiggerlb said:

It will also boil in the resivor tank at times.

That says to me you're getting combustion gases into the coolant if the reservoir tank is acting like it's boiling and the bubbles you think are steam are actually exhaust gases from head gasket problem or worse leaking into coolant and escaping into the reservoir and then venting to the outside.
You need to have the coolant checked for combustion gases at a shop.

What does the coolant level look like when the car cools? There is a procedure for refilling the cold engine with coolant to expel air from the heater core. If you have a dropping coolant level after driving and experiencing the heater being cool at times, you likely have a combustion leak. Do you hear rushing water sounds when running the engine at idle or if you rev it up to 2000 or 2500? That indicates air in the heater core.

The 3100 engine has had it's share of failure points. How many miles are on this puppy?

Mr_Shiftright

You can buy a simple kit at an auto parts store that tests for combustion gases in the coolant.

Yes I think the 3100 engine has a problem with intake manifold gaskets causing coolant intrusion into the oil. Very common, so have that checked out.

t_j_dusky

You said the air blows hot on the expressway and cool down city roads? If so then you most likely have a blocked heater core. Very common problem. Take it to a ready rad or your mechanic and tell them to flush your heater core

tiggerlb

I ruled out the heater core all together I by passed it. The car can sit in park and idle for an hour + with out overheating but then just a short trip around the block it is over heated. and back spewing water out the over fill hose on the resivor tank. I am leaning towards a bad head gasket or a warped head. Even though there is no a single bit of the normal signs of this like white smoke from the tail pipe or the milky looking oil. This car is not meeting any of the traditional signs. I have put the car up till next tax season when i will have the money to fix the major issues. I did go out and buy another grand am a 2004 for the mean time. I like my 2001 grand am GT best because it has the sportier feel and look it is also the wide track. It feels much better to me to drive than my 2004. Thank you ll for taking the time to answer my question.

Shanandoah266

Ok bare with me here because at first my answer will seem ti make no sence. Ive had been having the exact same problem with my 2000 grand am. I life depends on my car running so it was getting very worrisome for me. Especially when it got so bad I had to have a head gasket done. After having the head gasket done and had checked everything you would normally think would have any effect on the cooling system, I was still having the same problem. New head gasket and - 500$ I was at my wits end. Then my baby wouldn't start one day. I had been running errands all day and on one of these errands my baby just wouldn't start. She would crank over but would not start. Well I do all my repairs myself and im reasonably new at this repair stuff so I do alot I mean alot of research on you tube before I do any repairs. Well my conclusion was a bad fuel pump. So I pull out my gas tank slip in a new fuel pump. Fuel filter. Change my oil, oil filter and air filter while I'm at it. Well during my days of research I ran across one video talking about all the things a bad fuel filter could effect. But when it breaks mentions that a bad fuel pump could make your car over heat I scammed past it thinking I must have heard that wrong cause after all what could a bad fuel pump have to do with it. Well I get the work done turn my key and yes my baby starts up and purrs like a kitten. I kept a close eye at my fuel gage to make sure I had no leaks and of corse I also kept a diligent eye on my temperature gage as I had become accustomed to doing. I instantly noticed my temperature gage was not in its normal place witch would be straight up and down in the middle and tempting to go over the line into the too hot area. It was just below the middle line now. Right where it should be but never before had been. It stayed there. Heater on or not it stsyed right where it was supossed to be. Ever since that day I put in a new fuel pump my car has not over heated. I can drive around on a hot day without my heater blaring and she won't over heat. I have tried to find that video again so I might learn what a fuel pump has to do with the cooling system but I haven't been able to find it. My car is still running cool I have relaxed on stressing over getting her too hot and breaking down again. Who would have guessed that a new fuel pump would take care of my over heating issue. A new pump is only 87$ filter $17$. So for $100 i now have a very cool trust worthy car. My next project is fixing the driver side window that won't open or close. Same issue that many other grand am have. Good luck and trust me. Change your fuel pump, its not at all as hard as it sounds. Try it, you will be astonished. And free of your over heating problem. Good