Car overheating...

silverdoctor · #1 05-01-2018, 03:54 PM

Friends daughter has an older Grand Am that's been overheating. It's a 2003, 3.4L V6.

Overheated last week, filled it up, let it come to temp and coolant was flowing out of the filler reservoir overflow. Didn't seem like there was any flow of coolant through the lines at temp. And no other leaks. Changed the thermostat, filled it up and it was great for a week and a half. Now it's dry again, overheated. T-stat change on this thing is a bear, GM engineers need a kick in the keister.

Only thing I noticed, it calls for dexcool and it's the green coolant, but that shouldn't matter - been like that for years.

What else could it be? Sudden blockage somewhere?

Sooner · #2 05-01-2018, 04:06 PM

Has to be going somewhere, if it's not on the ground or on the carpet under the dash, I would pull the dipstick to see if the coolant is in the oil pan? Should see a very high oil mark if it is.

Could be a air pocket/air lock. In the body shop, we would jack up the front of the car when refilling coolant. Kinda keeps the bubbles rolling to the top. Are you filling it up with the car running?

silverdoctor · #3 05-01-2018, 04:28 PM

Quote:

Originally Posted by Sooner

Has to be going somewhere, if it's not on the ground or on the carpet under the dash, I would pull the dipstick to see if the coolant is in the oil pan? Should see a very high oil mark if it is.

Could be a air pocket/air lock. In the body shop, we would jack up the front of the car when refilling coolant. Kinda keeps the bubbles rolling to the top. Are you filling it up with the car running?

She's getting a friend to look at it later, i'll talk him through what to look for. hope it's something minor. Really don't want to go back in to pull the t-stat, that's painful.

gloszz · #4 05-01-2018, 04:35 PM

Did you bleed the lines from air? Lots of guys fill it and think its good to go but you need to bleed it, otherwise it will keep overheating.

silverdoctor · #5 05-01-2018, 04:43 PM

Quote:

Originally Posted by gloszz

Did you bleed the lines from air? Lots of guys fill it and think its good to go but you need to bleed it, otherwise it will keep overheating.

Yes, the one thing GM did right was put a coolant bleeder in the system. Ran fine for a week and a half, that's the odd thing.

spyguy 0-0-7 · #6 05-01-2018, 04:55 PM

I had a similar thing happening. It started as over heating then a slight puff of white sweet exhaust. It was a 3.4L. Ended up being the head gaskets.
Hope it's not. Good luck.

gunluvr · #7 05-01-2018, 05:45 PM

Most likely head gasket.Is the exhaust smoke white? Indicates burning glycol. Compression gasses in water jacket pressurizes cooling system. Pushes coolant into reservoir, or out rad cap.

RandyBoBandy · #8 05-01-2018, 08:45 PM

Are the cooling fans working? Pull the oil cap off and see if there is a foamy substance under it

Little red riding hood · #9 05-01-2018, 08:52 PM

If you're getting bubbles in the radiator with the cap off and engine running, you've got a cracked cylinder head.

silverdoctor · #10 05-01-2018, 09:20 PM

Haven't heard back from her yet, might have to take a run up tomorrow for a look.

When I replaced the t-stat, there was no white smoke, and she didn't mention anything this time either. I doubt the head gasket is an issue. The fans are working as well.

Might have to pull the T-stat and let it run without for a while.

Dr. Phil A · #11 05-01-2018, 09:30 PM

Dex cool turns acidic and eats the gaskets. I have done lots.of intakes and head gaskets on GM prodcuts with Dex Cool. If the coolant is not changed regularly it's starts the process. If the intakes blow the head gaskets are about a month later.

silverdoctor · #12 05-01-2018, 09:31 PM

Quote:

Originally Posted by Dr. Phil A

Dex cool turns acidic and eats the gaskets. I have done lots.of intakes and head gaskets on GM prodcuts with Dex Cool. If the coolant is not changed regularly it's starts the process. If the intakes blow the head gaskets are about a month later.

It's not running Dexcool, just ethylene glycol. I guess at some point someone changed it out.

sako1 · #13 05-01-2018, 09:32 PM

Couple things to double check. The low speed cooling fans will come on at 220°. The high speed at 235° . Make sure they are getting commanded on. Coolant temp sensor is a common problem with this. If they are all working fine it very well could be a headgasket problem. Which is quite common on this car.

Dewey Cox · #14 05-01-2018, 09:35 PM

The 3.4 was bad for head gaskets going. (So I am told)
I had a grand am from 2000 or so.
I filled it full of water, and drove straight to the dealership to trade it off.

gulfman · #15 05-01-2018, 09:56 PM

Quote:

Originally Posted by silverdoctor

Haven't heard back from her yet, might have to take a run up tomorrow for a look.

When I replaced the t-stat, there was no white smoke, and she didn't mention anything this time either. I doubt the head gasket is an issue. The fans are working as well.

Might have to pull the T-stat and let it run without for a while.

Don't pull the T-stat unless you aren't 100% sure it's installed correctly. The T-stat will slow the coolant flow down to give the radiator a chance to do the heat transfer allowing cooler coolant back into the engine. If the coolant circulates to fast your just putting that overheated coolant back into engine. Look for air bubbles burping in rad with cap off, would lean towards head gaskets before cracked head, or you could just confirm by pulling spark plugs and pressurizing cylinders with shop air and look for bubbles.

Peace Meal Farm · #16 05-01-2018, 11:22 PM

These things were famous for intake gaskets. They have a wet intake.

petew · #17 05-02-2018, 03:44 AM

Do a pressure test on the rad and see if it holds pressure.

gulfman · #18 05-02-2018, 05:26 PM

Quote:

Originally Posted by Peace Meal Farm

These things were famous for intake gaskets. They have a wet intake.

My experience with intake gaskets is they develop a external leak or leak coolant into oil, not pushing coolant into and out of overflow tank. Still suspect head gaskets but need to pressure test to confirm.

Trap Shy · #19 05-02-2018, 05:44 PM

Quote:

Originally Posted by Peace Meal Farm

These things were famous for intake gaskets. They have a wet intake.

I had 1 go with less than 20,000 miles

silverdoctor · #20 05-02-2018, 07:52 PM

Spoke with a family member, been a journeyman for 20+ years and has worked on these. Gave more ideas. Could be blocked heater core, coolant reservoir cap lost pressure or the water pump impeller is toast. Didn't have a chance to get up there tonight.

sako1 · #21 05-02-2018, 10:30 PM

Quote:

Originally Posted by silverdoctor

Spoke with a family member, been a journeyman for 20+ years and has worked on these. Gave more ideas. Could be blocked heater core, coolant reservoir cap lost pressure or the water pump impeller is toast. Didn't have a chance to get up there tonight.

Heater core definitely won't be the problem. Rad cap is possible but unlikely. Water pump could be a problem but should do it consistently.

gtr · #22 05-02-2018, 10:39 PM

Top end issue. Intake or head I would think.

brslk · #23 05-03-2018, 01:16 AM

Do you have access to and IR temperature gun? Let it run till it reaches operating temperature and then check all the lines with the gun.
I can't imagine the heater core being blocked having anything to do with it.
Could be a bad head gasket but if there's no white smoke (even on start up) and no bubbles or milky oil then I doubt that too.
A quick cylinder pressure test will let you know if the head gasket is toast.
Not doubting your ability as a mechanic but is there any possibility that you installed the thermostat backwards? It happens to even experienced mechanics.
From what you've posted, it sounds like the impeller. Or possibly one of the electric fans isn't kicking on. I'm not sure if those used a coolant temperature sensor to turn the fans on or if it's computer controlled. It could even be a bad connection in the fans wiring circuit.

Kim473 · #24 05-03-2018, 06:14 AM

Had a rad cap that would not hold pressure once, and the engine was over heating. Flush system as the rad could be partially blocked, change rad cap. Cheapest and easiest 2 things to do first.

gulfman · #25 05-05-2018, 07:15 PM

Quote:

Originally Posted by silverdoctor

Spoke with a family member, been a journeyman for 20+ years and has worked on these. Gave more ideas. Could be blocked heater core, coolant reservoir cap lost pressure or the water pump impeller is toast. Didn't have a chance to get up there tonight.

With answer like that (heater core) must be journeyman carpenter

RandyBoBandy · #26 05-05-2018, 09:07 PM

Quote:

Originally Posted by gulfman

With answer like that (heater core) must be journeyman carpenter

does it ALL outdoors · #27 05-05-2018, 10:21 PM

A friend had the exact same problem, it was an air lock. We raised the front of the vehicle and on the coolant pipe going into the engine from the rad there is a small bleeder screw, bleed it out. We had to do his a couple times before it took but we got er. He hasn't had any problems since

Habfan · #28 05-05-2018, 10:34 PM

Quote:

Originally Posted by sako1

Couple things to double check. The low speed cooling fans will come on at 220°. The high speed at 235° . Make sure they are getting commanded on. Coolant temp sensor is a common problem with this. If they are all working fine it very well could be a headgasket problem. Which is quite common on this car.

Good call !

gtr · #29 05-08-2018, 12:41 PM

Any update on the fate of the car?

raab · #30 05-08-2018, 12:55 PM

Headgaskets gone