UPDATE - Cooling system problem on 97 SL2

66dartdave · 11-15-2004, 07:21 PM

I decided to do a new post on the cooling system. I had it tested because it was over heating. I had already put in a new water pump and thermostat. When I replaced these items, I drained the system and refilled with Prestone instead of the GM orange stuff. I took it to a shop and was going to have it power flushed, thinking that the orange coolant and the prestone had reacted with each other and was plugging up the works. I was told that the coolant was visably flowing freely so they did a pressure test. I don't know how they did it or anything about it. They called and told me that their pressure gauge went up to 30psi, and my cooling system pegged the needle. I think what they were saying is that the system built up pressure on its own to at least 30psi. Now, I know that 30 psi is roughly twice what the cap is rated for, but if there was really that much pressure in the system, I would think that something would have blown by now (I'm still driving it). I haven't really had to add any coolant, either. They said they think that the head gasket blew into one of the combustion chambers and was pumping extra pressure into the system on the compression stroke. Now, I haven't checked for water in the oil or anything myself, but haven't noticed any when changing the oil and filter. What do you guys think?

dave

**Ssicarman** · 11-16-2004, 03:11 AM

I doubt that you have a further problem with the cooling system. The only thing that perhap I can think that they did was run the engine with a pressure tester on the surge tank to get to 30 PSI. This is something that should not be done. Even at that I don't know if the system would actually get that high a pressure. If the head gasket was bad and the coolant was open to a cylinder that cylinder would fill with coolant on a hot engine shut down and you would notice problems when you started the engine. Not to mention the coolant would be down.

66dartdave · 11-16-2004, 03:22 AM

Hmmmm, I hadn't thought about the coolant filling up the cylinder. I think you're right about them running the engine while doing a pressure test. I think I might change the thermostat again. It seems to warm up to about, or a little past, the 1/4 mark on the temp gauge, but then slowly creeps up to not quite the half way mark. Does that sound normal? Or does it sound like maybe the thermostat is perhaps stuck open or at least not working correctly. I hate to change that again, but if I have to, I have to.

dave

Robert-sl2 · 11-16-2004, 06:00 AM

Quote:

Originally Posted by 66dartdave

Hmmmm, I hadn't thought about the coolant filling up the cylinder. I think you're right about them running the engine while doing a pressure test. I think I might change the thermostat again. It seems to warm up to about, or a little past, the 1/4 mark on the temp gauge, but then slowly creeps up to not quite the half way mark. Does that sound normal? Or does it sound like maybe the thermostat is perhaps stuck open or at least not working correctly. I hate to change that again, but if I have to, I have to.

dave

That is a normal temperature reading. The fan doesnt kick on till almost the 3/4 mark so you are well in the the green

66dartdave · 11-16-2004, 02:33 PM

Robert, again, thanks for the reply and supporting confirmation. I'll just keep an eye on things and see how we do. Should be Ok this winter anyway - LOL.

dave

nyce · 11-16-2004, 08:07 PM

Quote:

Originally Posted by Robert-sl2

Quote:

Originally Posted by 66dartdave

Hmmmm, I hadn't thought about the coolant filling up the cylinder. I think you're right about them running the engine while doing a pressure test. I think I might change the thermostat again. It seems to warm up to about, or a little past, the 1/4 mark on the temp gauge, but then slowly creeps up to not quite the half way mark. Does that sound normal? Or does it sound like maybe the thermostat is perhaps stuck open or at least not working correctly. I hate to change that again, but if I have to, I have to.

dave

That is a normal temperature reading. The fan doesnt kick on till almost the 3/4 mark so you are well in the the green

It Is normal but if you have the factory ECT's you can change them out for the Brass ones solves alot of problems with overheating issues...

ian12 · 11-17-2004, 04:23 AM

its normal to drive it at about the 1/2 way mark. thats where most all gms sit. if it sits slightly above the 1/4 mark then the ects probably is bad or thermostat is faulty. another thing is, dont worry about the coolant kind. prestone makes some new stuff that is yellow and mixes with everything. all coolant times are the same but the dex cool has some added stuff to last longer. just use the new prestone stuff that is yellow, its what i have after i flused, changed thermostat and ects and it works fine.

66dartdave · 11-17-2004, 09:08 PM

I just put the new, "second improvement", CTS in that I got from the local Saturn dealer. I am wondering if my new thermostat is not working like it should. It warms up pretty quickly to the 1/4 mark, but then won't get close to the 1/2 mark until I've driven it a bit. Has yet to get exactly to the 1/2 mark, but gets close. I'll keep an eye on it and perhaps change out the thermostat again if it starts looking more suspicious.

dave

Anony00GT · 11-17-2004, 11:58 PM

Quote:

Originally Posted by 66dartdave

I just put the new, "second improvement", CTS in that I got from the local Saturn dealer. I am wondering if my new thermostat is not working like it should. It warms up pretty quickly to the 1/4 mark, but then won't get close to the 1/2 mark until I've driven it a bit. Has yet to get exactly to the 1/2 mark, but gets close. I'll keep an eye on it and perhaps change out the thermostat again if it starts looking more suspicious.

dave

Sounds like it's working properly now.

nyce · 11-18-2004, 01:00 AM

Man your lucky in this Heat in FL mine is always at 3/4 in traffic...