: 99 SLS overheating, need help

06-05-13, 01:56 PM
I have a 1999 SLS that keeps over heating. I just flushed the coolant and put new coolant in but the problem still exists. When driving and the car starts to heat up I will crank the heat on, sometimes when it gets hotter the heat blows out cool air. I am trying to pin point the problem but I am not car savy at all so I am doing my best and appreciate any help I can get. When I pull over after the car starts getting hot the coolant bubbles out the coolant cap after I open it a little to release the pressure. Are there any easy steps to pin point the problem so I don't go to a mechanic & have him fix 10 things that isn't the actual problem? I really love my SLS but its now summer & I can't drive my car at all. I've been told it could be a spring in the thermostat and possibly a water pump. Also is it a must to use the GM orange dex cool. Thank you everyone for any help or suggestions given.

06-05-13, 02:43 PM
Sorry man, I hope you didnt pay alot for the car.
If you are machanical it can be fixed, just be aware of the $$$.
I'm into mine about $850 (parts, tools & equipment) so far. I still need an assortment of new bolts, sealant, sparkplugs, coolant and a battery. Fortunatley I only payed $600 for the car and it came with a set of new Bridgestone's.
Good luck.

06-05-13, 03:17 PM

Another '99 :nono:

Check the purge line for flow first. If that checks out OK, then borrow a block test kit from AutoZone and just pay fro the test fluid. Run the test after an overheat episode to confirm the failed HG. That's a pretty easy way to pinpoint it.

No Dex is not a must. Any coolant will do.

06-06-13, 02:38 AM
Just don't mix the two