98 SLS overheating...

chrislikescrazy · #1 (**permalink**) 07-01-07, 09:55 PM

I have a 98 seville sls, it overheats randomly and loses coolant.
When it heats up it pukes coolant through the reservoir cap. I did a compression test, all the cylinders read normal. I replaced the thermostat and there are no visible leaks on coolant system.

someone help i cant think of anything else it could be.

**Ranger** · #2 (**permalink**) 07-01-07, 09:59 PM

Compression test won't tell you anything. Do a cylinder pressure test. Check the purge line, tensioner, thermostat and cap.

iametarq · #3 (**permalink**) 07-01-07, 10:07 PM

How long between coolant losses and refills? I could not find a leak for the longest time, and with the help of Ranger, it appears to (hopefully) just be the gasket for the water pump cover...

zonie77 · #4 (**permalink**) 07-02-07, 12:52 AM

Ranger, you have to save the answers and repost them. You'll save a lot of typing!

**Ranger** · #5 (**permalink**) 07-02-07, 01:10 AM

Yeah, I should store them. This is getting old fast.

lisekpl · #6 (**permalink**) 07-02-07, 01:36 AM

Also check the fans, make sure they are coming on, or at least at the right time. ALso check your exhaust, and just because you cant see any white smoke doesnt mean you're not burning coolant.

Man, I'm happy I'm past that whole nightmare, it's nice to have a car that doesn't overheat anymore.

chrislikescrazy · #7 (**permalink**) 07-04-07, 03:53 PM

how do i test the purge line

**Ranger** · #8 (**permalink**) 07-04-07, 06:42 PM

Pull the line off of the surge tank at idle (engine cold). It should flow coolant. Flow will increase with RPM. If it flows coolant it is OK. If not, locate and clear the obstruction.

chrislikescrazy · #9 (**permalink**) 07-15-07, 12:54 PM

checked the purge line and its flowing constant and increases with RPMs. i hear fluids sloshing around whenever i accelerate or turn. the only thing i have not checked or changed is the coolant cap.

**Ranger** · #10 (**permalink**) 07-15-07, 10:04 PM

Sounds like you have air in the heater core.

chrislikescrazy · #11 (**permalink**) 07-16-07, 06:34 PM

i replaced the cap and it still will shoot about 3/4 up the gauge and randomly drop to normal if it is the heater core how do i deal with that

ej2000n · #12 (**permalink**) 07-16-07, 08:23 PM

Best bet would be to take it to a shop and get it tested. overheating is never a good thing and will only lead to more expensive repairs if you continue to drive the car.

zonie77 · #13 (**permalink**) 07-16-07, 11:25 PM

Quote:

Originally Posted by chrislikescrazy;

the only thing i have not checked or changed is the coolant cap.

There are plenty of things you haven't checked yet.

Did you check the water pump belt? tensioner? radiator plugged? Coolant for exhaust gases? Crossover for leaks? Water pump for leaks?