Cooling Issues

[netadmin67]

Hello. My '95 Cobra SVT seems to be having cooling issues. The heater core is very hot but the radiator is not. I replaced the thermostat and replaced the coolant. Thermostat is 180 degrees. I tested the stat in a pan of hot water for functionality but I don't know the exact temperature that it opened.

I ran the engine with the radiator cap off and the coolant does seem to rise in the radiator but it doesn't seem to be moving around very much if at all.

So I took the thermostat back off again and it looks like I might have put it on slightly askew. It's a vertical mount (as you probably know) and I'm going to try to use some sealant to hold it in place. I had a heck of a time trying to make it stay put until I could re-attach the elbow housing.

The water pump seems to be squealing a bit until it's warmed up. But the pump doesn't leak. The squealing is a sign of it failing? I just purchased an infrared thermometer to do some testing with.

Any suggestions for how to tell if my water pump is producing sufficient output and/or if I have an air bubble stuck somewhere?

Thanks in advance!

 

[Boosted92LX]

Hello. My '95 Cobra SVT seems to be having cooling issues. The heater core is very hot but the radiator is not. I replaced the thermostat and replaced the coolant. Thermostat is 180 degrees. I tested the stat in a pan of hot water for functionality but I don't know the exact temperature that it opened.

I ran the engine with the radiator cap off and the coolant does seem to rise in the radiator but it doesn't seem to be moving around very much if at all.

So I took the thermostat back off again and it looks like I might have put it on slightly askew. It's a vertical mount (as you probably know) and I'm going to try to use some sealant to hold it in place. I had a heck of a time trying to make it stay put until I could re-attach the elbow housing.

The water pump seems to be squealing a bit until it's warmed up. But the pump doesn't leak. The squealing is a sign of it failing? I just purchased an infrared thermometer to do some testing with.

Any suggestions for how to tell if my water pump is producing sufficient output and/or if I have an air bubble stuck somewhere?

Thanks in advance!

Have you checked your lower radiator hose to see if it's collapsed? If it is, the pump can't draw water and i could see it making noise then. Just a shot in the dark, first guess would've been stat.

 

[jAEded]

To help with the air, one thing you can do is jack the front end up as high as you can when you fill the radiator. You are trying to make the radiator the highest part in the system so that the air works its way into the radiator instead of stuck in the block or intake somewhere. Also, fill it and let the car completely warm up. Then let the car completely cool down and the level in the radiator should drop significantly. One other thing that helps is if you buy a thermostat with the little hole and pin in the opening disc. This lets small amounts of air and coolant through without having to wait for the thermostat to open.

If you are running a high volume pump its possible its cavitating. If you put a stethoscope on the water pump you can actually hear it if thats the case.

 

[netadmin67]

Thanks for both ideas. I'm going to try after work today and re-post here.

 

[mikestang63]

get a lysle fill cap- best $25 you will spend.

 

[netadmin67]

Removed lower radiator hose and found a spring inside. I assume that it's there to prevent the hose from collapsing. A bunch of coolant came out of the engine and the radiator. So I put the thermostat back in and will fill with coolant tomorrow and test again. The front end is jacked up in hopes of helping to clear any air bubbles. Thanks for everyone's help. Will post again tomorrow.

 

[netadmin67]

Updates: Re-installed thermostat, let sit overnight, refilled coolant, ran car to warm and all seems well. I can rev the engine above 2,000 rpms now so I think the ICM was an issue. Replaced that (the ICM) and things are good. Went for a short drive and checked temperatures again. Coolant fan came on near the end of my drive, as expected.

Seems like the thermostat and air bubbles (after refilling with coolant) were probably my issues. Jacking up the front end of the car might have helped with air getting trapped in the system. I feel much better about my 'stang cooling itself properly now.

Thanks to everyone for the suggestions and guidance.

 

[7991LXnSHO]

PLEASE still use a LONG screwdriver or a real mechanic's stethoscope (cheap at HFTool) to see what the noise when cold is/was. Water pumps have sealed bearings and have no reason to squeal wet or dry, except as a warning that they are going to size and possibly blow chunks.
If you are running an electric fan, you probably are using it as a pull unit and have removed any mechanical fan and clutch or spacer. But if the shaft fails when the bearings seize, the pulley can still damage your radiator as it flies off. It could as easily be any of the other accessories, so please poke around and listen.

 

[netadmin67]

Thanks. You're right and I appreciate the input. Will do