Overheating

[jczar]

My daughter has a 96 Chevy Monte Carlo. We recently replaced the water pump with an aftermarket type pump due to leakage. The thermostat was replaced. Now the engine overheats going up when going up hills. I noticed the impeller on the aftermarket pump looked smaller than the original. The Autozone guy said this is the replacement and is just a different design. Installing the pump was a real pain in the whazoo so before I tear into this again I wanted some opinions if there is anything else I should look at.

[trularin]

Well, let's see.

1. Was the collant rusty?
2. Did you put the correct mix in?
3. Did you purge the system?
4. Was the T'Stat you put in the same temp as the one you took out?
5. Did you add a burp hole in the T'Stat?
6. Did you pressure test the system?
7. Did you pressure test the cap?
8. Did you plug in all the cotton pickin wires after the pump was installed?
9. Does the fan turn?
10. Does the fan cycle?

These should get you started before you start yanking parts off. I did the timing belt on the PT Cruiser four times before it turned out to be a sensor.

[Ron61]

All good advice from Tru. Maybe also run the car with the cap off and see if the water is circulating. I have put a piece of pasteboard in front of the radiator to make mine warm up to see if the thermostat opens and watched the water. Do you have an overflow tank, and if so, does it have the right amount of water in it when the car is cold?

By the way Tru, just where on the sensor located on the timing belt?

Ron

[jczar]

Thanks for the quick reply.
1. Was the collant rusty? Coolant look good.
2. Did you put the correct mix in? Yes, 50/50
3. Did you purge the system? Yes
4. Was the T'Stat you put in the same temp as the one you took out? Yes
5. Did you add a burp hole in the T'Stat? No, I didn't drill a hole.
6. Did you pressure test the system? No, didn't have the equipment.
7. Did you pressure test the cap? Cap appeared to be okay. See below
8. Did you plug in all the cotton pickin wires after the pump was installed? Didn't need to pull wires, but engine does run smooth.
9. Does the fan turn? Yes, fan works.
10. Does the fan cycle? Yes.

Pressure cap: When overheating we can see bubbling in the coolant
reservour.

My daughter called me today and said she took the car to a mechanic and he thinks it's the head gasket.....HUH??? Motor oil looks clean, no gray/white smoke from exhaust, no external leak and reservour level holding okay.

One thing I didn't check was if the radiator fins were clogged preventing an air flow. I'll check that tonight.

Thanks guys.

[trularin]

Pressure test the system. Don't know where you live, but a pressure tester will give you an idea if there is a leak, head or other wise. Should be able to hold 15 pounds for 4 hours at least.

Head gasket??? Pressure test the system and see if she holds. If it is a thermal crack, one that opens with heat, it will make it self know through fluid on the ground, white sweet smelling smoke in the exhaust or chocolate milk in the oil pan.

There are only so many places the water can go.

Hope this helps.

Ron, the sensor didn't have anything to do with the timing belt. It broke at the same time I was working on the timing belt. I thought I had FUBARed the timing as the engine ran like sh!t each time.

[Ron61]

Tru is correct about the pressure testing. I bought a test set up years ago and it has saved me money several times. Also helped me find some pin holes in radiator fins and a bad cap.

Tru,

I knew the belt didn't have sensors. Just rattling your cage a little. I watch Jack change them almost on a weekly basis as he does a lot of them.

Ron

[tcrist]

JCZAR,

Was the car overheating when you changed the water pump? Your first post said that you changed it because it was leaking. If it was only leaking and did not overheat when you changed the water pump, then I would think that the water pump does not have enough flow. A smaller impeller could cause that.

Terry

[trularin]

We were trying to avoid having to pull apart the front of the car as he asked.