Need help fixing an overheating 95 Grand Am 3.1

[Arokh]

Here's the problem, when I first start driving in the morning, I have mild heat. But after 5-10 mins, heat goes out and temp gauge goes nuts (into the red). Usually if I just let it run for another minute or two, the heat comes back, temp gauge goes back to normal, and it works fine for the rest of the day. But not even that worked this morning, so something's wrong.

Does this sound like air in the coolilng system? I recently replaced the radiator, thermostat, and intake manifold gaskets to plug up some leaks, so I think it's plausible.


What's the right way to bleed this car? I tried the bleeder valve on the water pump pipe but that was only good for a coolant fountain.


So instead, I opened the radiator cap and ran the car. The first cycle seemed pretty violent, lots of air bubbles, lots of coolant coming out, lots of gurgling coming from the radiator. The 2nd, 3rd, and 4th cycles were much improved, but it still seems like it's burping out air? How many times should I have to do this? Am I doing it right? Should it be blowing out a lot of the coolant during this process?


I've thought of maybe plugged heater core or inefficient water pump. Especially given that sometimes to get it to "release", I need to punch the gas. But what I can't figure out is why when it finally does "release", it's fine for the rest of the trip. It seems that a plugged heater core or bad water pump would make it not work all the time.

Thanks!

[xeroinfinity]

Does sound like trapped air in your cooling system.

Did you turn your heater on ?
Air tends to get trapped in there, but it could be a clogged heater core.
You can feel the two heater core lines(when the engines hot) and see if they are hot.

When you bleed it from the bleeder valve make sure the engine is up to operating temp.
With the bleeder valve it can take some time to clear the air if thiers a big pocket. You are actually supposed to attach a large hose to the bleeder, then run it to the resivoir and run until the air is gone.
Also if the thermostat is in backwards, spring side goes into engine.

If you dont know when the last time your water pump was replaced that might be worth checking out.

If it keeps spewing coolant out the radiator cap when its open then it is possible your head gasket(s) is bad. Did it do this same thing before the LIM change ???

Good Luck

[Arokh]

That bleeder valve isn't really a valve, it's like a plug. It doesn't have a nipple on it like brakes usually do, how would I attach a hose to it? Do they make some sort of tool kit for bleeding the cooling system? I might need to try to do that.

It did this before the LIM gasket replacement, but it's very recent.

I wouldn't say it spews out coolant, but if I open the bottle cap and let the motor run, the level will slowly rise, then overflow (dumping coolant on the ground), burp out some air, repeat several times, then the level drops again and everything is fine.

But I've gone through this cycle about 5 times and it's still doing it's funky overheat thing.

I've dealt with a bad head gasket before and this just doesn't seem the same. Still feels like air, but it seems like no matter what I do, I can't get all the air out.

[xeroinfinity]

Originally Posted by Arokh

That bleeder valve isn't really a valve, it's like a plug. It doesn't have a nipple on it like brakes usually do, how would I attach a hose to it? Do they make some sort of tool kit for bleeding the cooling system? I might need to try to do that.

It did this before the LIM gasket replacement, but it's very recent.

No it is not like a brake bleeder. the small fitting in the center has two holes that run down through the center of the piece. Purple arrow is the bleeder.

It can take up to 45 minutes if the whole systems been drained. No kit I know of but thier could be IDK.

Also you said it did do this before the LIM was changed ?

BTW did you see this;
http://www.automotiveforums.com/vbul...d.php?t=718130

[Arokh]

That's a good guide, I'm going to go try that now, thanks!

I don't recall when this started, but it was before the LIM gasket change. You see, I've been dealing with coolant leaks on this pile of crap and I'm sure I ran the bottle dry and introduced air during all of this.

Now I'm pretty sure I have all of the leaks taken care of, I just need to get that air out.

[Arokh]

Well I tried bleeding it, but I guess I don't really know what I'm looking for. Should I be seeing air then coolant coming out of that little hole on the bleeder plug? Because I'm not. I did see lots of air bubbles and some coolant, but looked like it was coming out of the threads on the plug, not the little hole. I was out there for about a half hour and can't really tell when the air stops (it goes in waves). I'm going to let the car cool off so I can check that bleeder plug and make sure it's not plugged (and not letting air out).

Also, when sitting at a stop light, the heat gets noticably cooler. But then as soon as I go again, it goes back to normal. The temp gauge seems to stay normal.

Sound like I still have air in there or sounding more like a water pump? I suppose I'm going to have to unbolt the motor mount again to change the WP eh?

[inafogg]

hello are we sure head gasket is ok!! i dont no how bad it over heated?? just a thought hope im wrong good luck

[Arokh]

No, I'm not sure it's not the head gasket. It doesn't feel like it, as I've been through it before, but I'm not really an expert. I'd rather try the cheap fixes first.

I took the bleeder valve off to inspect it and I think it's broken. That might be why I can't bleed it correctly??? It looks like there's supposed to be another fitting on top of it that is broken off (hence, I can't open the valve, just remove it from the pipe). See attachment for picture. I'll pick up another at the dealer tomorrow and give it another go. Maybe I'll be able to bleed it correctly this time!

http://s39.photobucket.com/albums/e1...eder_valve.jpg

[xeroinfinity]

yes it will bubble out the valve with some coolant.
When I use that I open until the fluid is constant, close allow to run for a few seconds then repeat. Like you said in cycles. remember to open you heater to high heat also.

And yes that is a broken bleeder. $10-12 at the stealership.
Sometimes you can find simular parts at a hardware store for much cheaper.

Pretty easy to check the waterpump and worth the trouble.

One other question after the LIM change did you do a coolubg system flush ??
If not you could have crap in the system causing a blockage, and that would cause some overheating issues.
Good Luck

[Arokh]

Thanks for your help xero, I will try the new bleeder and let you know how it goes.

As for coolant flush, no I didn't do that because after replacing the radiator, this thing has pretty much all new coolant in it. But this problem did exist before the LIM change, so I don't think that made it any worse. (the motor ran like crap for a few minutes after the LIM change, but it worked it all out, and a fresh oil change made it run like a champ)

[inafogg]

might be worth knowing?? a block tester is'nt expensive & would tell you if head/ or gasket is failing.if all else fails after you get new bleeder i'd look into it

[xeroinfinity]

You mean a compression tester... ?

$20-30 is worth spending IMO.
I'd at least check that out before pulling off the heads.

[inafogg]

no it checks for exhaust in cooling system called block tester any rad. shop could also do it

[xeroinfinity]

OK , I wasnt sure about the block tester, I usualy refer to it as a "combustion leak tester".
They can give false readings if a coolant flush was done recently, shows positive for hydrocarbons(which most flushes use a petro based cleaners). Realy only works if combustion gases are leaking into the coolant.

I usualy just use my emissions probe(sniffer), just dont get it wet. Or doing a compression leakdown.

Hopefully its not the head gaskets since he just done the LI, cause those would realy need replaced again.

[Arokh]

It doesn't have any coolant in the oil, or blowing any white smoke from the exhaust, or excessive pressure coming from the cooling system, so I hesitate to think it's head/gasket related (the reason for the LIM change was that it was leaking coolant externally onto the block, not inside the motor). It could be, I'm no expert, but in my experience with another car with a cracked head, it doesn't feel the same.

I put the new bleeder on it, jacked the front end up, and bled it. Lots of air. I mean I could hear it hissing for several seconds at a time before seeing any coolant. I did this several times over the course of about an hour and the amount of air coming out each time got noticably smaller. So it doesn't appear that more air is being introduced into the system.

Then I took it for a test drive. The temp gauge is behaving, but the heat is erratic. Especially if stopped at a stop light, it gets cooler. Keep in mind it is only about 10 degrees here. I also think that with all the air that came out, it's probably low on coolant. I'm going to let it cool down and check the level, and if necessary, bleed it again.