This is an old thread, but I have the same problem and didn't see an
answer that fit my problem.
The problem: It overheats quickly. This began a year ago. I replaced the
water pump and thermostat twice. So, in February, I gave up and just
drove my 93 suburban without a thermostat until now. So, today, I put in
a 3rd thermostat. All 3 are different brands, for what that's
worth???... (btw, while driving without the thermostat, the temperature
never got above 120)
When I drove down the road to test the new thermostat (today), the guage
went up to 250 before the thermostat opened up. I'm sure the guage is
working right cause the engine started to clatter, so I was easy on the
gas going back to the house and the temperature slowly dropped. I was
told it could be air in the system, I ran the engine without the
radiator cap on and waited for the thermostat to open, the level dropped
so I added more fluid. Since then, I can't seem to get anymore fluid in
there, infact, the level goes up and down in the neck of the top of the
radiator and some overflows a little with the cap off. Now, the
thermostat opens around 230 with the cap open. I closed the cap and now
it seems to open around 220. I'm not sure about trying to drive it yet.
If there is air in the system, is there an easy way to get it out? Or,
could there be something else wrong?
Sometimes a head gasket can blow without giving signs of water in the oil,
or out the exhaust. You have to remember those cylinders are like an air
compressor, under combustion the force can be great enough to push exhaust
gases into the water passages, but still will not leak back into the engine
when it is stopped. I know I've had this problem before and the harder you
drove it the hotter it got.
Also check the radiator in the front, run your hand over the entire surface
and see if the temperature is about the same. If you have a fairly cool
area, the radiator could be plugged inside. Also make sure the fins are
clean bugs can plug them right up and it will run hot. I had this happen on
an Astro van before. I run water over the radiator, then blow with
compressed air, repeat over and over till I can kneel down and see thru all
Hope this helps.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.