Help. Can't seem to stop overheating. [Archive] - GrandAmGT.com Forum

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Midnight GA
07-17-2010, 11:55 AM
Hi everyone. I'm having a hell of a time with a car that wont stop overheating. I'm not a mechanic, just a parts changer, so I'm hoping someone more knowledgeable than me might be able to shed some light on things for me. Let me start from the beggining. It's a 99 Grand AM GT, 130k miles, and a few months ago the LIM gasket started leaking. No coolant in oil or anything. Just some leakage from under the manifold between the heads. He put in a bottle of stop leak and that took care of things for a while. Then a few months later, it started to overheat. Almost no heat at all and the needle would start climbing and the coolant would spray right out the overflow tank hose. The water pump was leaking so I changed that but no help. I changed the cap but that didn't help. I flushed the system as best as I could and burped it but still no help. I even tried running without the t-stat, in case that was getting stuck but it didn't help at all. It just didn't seem to wanna circulate coolant and would just overheating. He put in a bottle of Blue Devil stop leak and that fixed the problem for about 2 days. So, i concluded must be pressure getting in the from one of the cylinders. I took the motor apart, put on another set of heads that i had pressure tested and resurfaced, put it all back together with a new t-stat, and low and behold, the heat worked great and the temp was sitting right around the 200 mark, but, as soon as the needle starts hitting the 200 mark, the coolant starts shooting out of the hose of the recovery tank. I hooked up a garden hose directly to the hose that feeds the radiator from the fill tank, open the radiator drain, and flushed it as best as I could. I've bled the system over and over, tried yet another cap, but still no help. Any ideas what could be causing this? Any ideas would be greatly appreciated and thanks for reading my long post.

AaronGTR
07-17-2010, 02:57 PM
First thing I'd say is, never EVER use that stop leak crap. It causes more harm than good.

First places to look are the obvious... pressure cap on the over flow tank, t-stat, water pump, etc... sounds like you've already covered all those. If it still overheats regularly, and if there are other signs like white smoke out the exhaust, then I'd say it's a bad head gasket. But you already fixed that too.

I can only hypothesize that it was a head gasket issue and you should have fixed that before using the stop leak. It's possible that the stop leak has clogged some coolant passages in your engine somewhere, and/or there is still air in the system somewhere (possibly also made worse by the stop leak). Any air in the system will cause it to not hold pressure properly and boil the coolant which will make the pressure cap vent.

Midnight GA
07-17-2010, 03:07 PM
Thanks Aaron for the reply. The car is running fine other then the coolant boiling out. It's not overheating and then boiling out. As a matter of fact, the temp gauge hasn't gone passed one notch over the half way point since I changed the heads and its over 90 degrees outside the past couple of days. I've been bleeding it for days but it doesn't seem to completely bleed out. There always seems to be some air in there. I know on my 2003, I've never had such a problem bleeding the system. Maybe it's just not completely bled or I'm not bleeding it correctly, IDK. I'll keep trying to bleed it. Maybe it's just air escaping and opening the cap. Thats exactly what it seemed like to me, but I've been bleeding it for so long, I thought maybe there was something I was missing.

B Weezy
07-17-2010, 03:19 PM
Thanks Aaron for the reply. The car is running fine other then the coolant boiling out. It's not overheating and then boiling out. As a matter of fact, the temp gauge hasn't gone passed one notch over the half way point since I changed the heads and its over 90 degrees outside the past couple of days. I've been bleeding it for days but it doesn't seem to completely bleed out. There always seems to be some air in there. I know on my 2003, I've never had such a problem bleeding the system. Maybe it's just not completely bled or I'm not bleeding it correctly, IDK. I'll keep trying to bleed it. Maybe it's just air escaping and opening the cap. Thats exactly what it seemed like to me, but I've been bleeding it for so long, I thought maybe there was something I was missing.

I don't know much about this, but this is relevant. My uncles Jaguar coolant hose had a leak at where it connects.. ;crap

juanvan
07-17-2010, 03:22 PM
If its boiling out - it over heating if the Coolant 2 water % is not right water boils easier the coolant - check your coolant ehow Video ;-) (http://www.ehow.com/video_2328529_test-antifreeze.html)

AaronGTR
07-17-2010, 08:27 PM
well, if the temp gauge isn't getting that high but you are still getting coolant out the vent hose it could be two things. 1) even though you replaced the cap, the new one could be defective, or 2) the overflow tank itself could be warped or otherwise defective and not allowing the cap to seal properly. Might want to replace that too, or both.

icecats87
07-17-2010, 08:50 PM
This is what happened to my car when the head gasket blew, it overheated for days after i fixed it, then i noticed that a lot of the hoses had crap from the stop the previous owner put in it. it blocked all the coolant from going in, maybe check the hoses

Midnight GA
07-18-2010, 11:22 PM
Swapped the tank and cap from my GA and still the same thing is happening. His tank and cap are also cooling my car just fine.

AaronGTR
07-19-2010, 05:08 PM
Weird. Well I guess you can rule that out then. Only other thing I can think of is some plugged hose or coolant passages in the block.

Midnight GA
07-19-2010, 07:35 PM
I hope so. Somebody suggested a cracked block.

juanvan
07-27-2010, 08:00 PM
Cracked block would be coolant in the oil or vic vs - and could have bubbles in the coolant - it could also have a miss fire bc of the loss of psi in the cylinder.

Try taking the lines off the top of the coolant bottle and see if they r moving coolant - maybe one is moving steam and that is how its coming out of the overflow - do this with the car off and turn the car over with. Someone else - less mess!

blazingerbs
08-03-2010, 10:32 AM
my car always overheats
it cant idle for long periods and i have observed the cooling fans only come on when i have a/c or defrost on. checked all related fuses and relays, but nothing.
had lim done, that stopped the coolant from boiling out, still overheats.
its absolutely fine on the highway which leads me to believe its a fan problem only
is there an easy way to make the fans come on when the car is on all the time?

remiljr
08-03-2010, 01:41 PM
my car always overheats
it cant idle for long periods and i have observed the cooling fans only come on when i have a/c or defrost on. checked all related fuses and relays, but nothing.
had lim done, that stopped the coolant from boiling out, still overheats.
its absolutely fine on the highway which leads me to believe its a fan problem only
is there an easy way to make the fans come on when the car is on all the time?
change your t-stat. if you want the fans to run you have to get a modded pcm

WidbyJ
08-03-2010, 07:15 PM
Actually you can just unplug the fans from the harness, the car won't care. Control them with a thermostat, switch, relay or direct power - it's up to you. Fuses are advised...

blazingerbs
08-04-2010, 09:23 AM
thanks widby, thats more along what i was thinking....
so im pretty good with electronics but not automotive
i want to find a 12V when ON always and hook up directly to the fans using the frame as the neutral? where is a good spot to get my hot from?

WidbyJ
08-04-2010, 09:42 AM
To get power I'd probably just draw direct from the battery, use an in-line fuse for safety. Better would be to find and use one of the extra circuits in the car, like the power feed for the sunroof or rear defroster - these should both only be live when the car is on. If you're using a switch or thermostat control I'd just use the battery power. You'll want to use a couple of jumper wires to test which wire to each fan is positive so they spin the proper direction. Good luck, this is pretty basic stuff if you are comfortable with wiring.

Tank
08-28-2010, 06:34 PM
I'm having the same problem, changed head gaskets, t-stat(removed right now), water pump, coolant bottle & cap & a radiator flush. In the morning on the way to work I can drive for about 25min then it starts to run hot. On the way home a few days ago I could only go about 10min then I had to pull over and add fluid. I have no idea what it could be. One mechanic said that even though the pump is just a few months old that sometimes they due crap out on you fairly new if its a refurb. I'm going to check that in the morning & hopefully it works.

AaronGTR
08-28-2010, 11:40 PM
Usually the pumps don't just stop pumping though. Usually the bearing and seal in them wears out and they start leaking fluid, but the impeller is still attached to the shaft and pulley so it's still working. It won't just stop pumping.

Tank
08-29-2010, 12:51 PM
yeah, that' kinda what i was thinking, it's cool I'll let him check it out because its free, but I've already started looking for another car.