Cooling Problems

Guy Montaquila

Registered User
Hi Everyone,
I have been trying to get my 90 SC to run a little cooler, so I started with just flushing and filling the coolant. I did it myself and it started running hotter than before. So I thought maybe I did something wrong so I took it to a shop to do it and now it is running even hotter. I suspect that there is air in the system, but not sure. Any advice.
 
At this point, I think the best assumption is that there is air in the system.. especially since it got worse the second time. Simply let your car run under low/no load and it will escape on its own. If you want, you can run the A/C to activate the low speed cooling fan and turn up the HVAC temperature all the way to help cool it off until the air is gone.

Hope that helps!
 
Actually, you need to keep the coolant bottle filled to the proper level when its hot to purge the air completely. When the car cools down, the contents of the bottle get sucked back into the radiator. If its empty, then air gets pulled back in.
 
That's why the thermostats for our cars have the little purge valves built into them. To help any trapped air escape.
 
Thanks, I hope it is just air in the system.
That's why the thermostats for our cars have the little purge valves built into them. To help any trapped air escape.
Can someone describe where the purge vavle is, or show a pic? I looked in my shop manual and I didn't see it or read about it. Can I still use it now, or only when filling the system?
 
You should not have to find the purge valve unless you think it is clogged.. the air will escape on its own. You can use the car at will, but as air escapes, it will leave empty space. The system will take coolant from your resevoir tank to fill this space, thus the need to ensure that your coolant tank does not run out of coolant.. or else it will take air back in instead of coolant. The amount of air inside can be suprising, so make sure to check it often & refill when necessary.

To be sure, just don't drive it so hard until everything looks normal. It shouldn't get critically hot for very long, as there is coolant in the system. Make sure your radiator cap is sealing well, or else it will allow air into your system. If replacement is necessary, I believe SCs use a 16 lbs cap.
 
any shop that does cooling system work should have a tool called and "airlift" it's made by 'U-View" and is carried on all the tool trucks and thru NAPA, it's only been on the market for a couple years but basically what it does is you hook it to shop air and it pulls vacuum in the cooling system, then you stick the hose in the coolant and it fills up in like a minute with NO trapped air! It's a slick tool, about $150 so you probably dont wanna buy one but any good shop should have one. Lots of newer cars have this problem, so it's become a real problem for shops......
 
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