A car question

#1 Postby **coriolis** » Thu Jan 27, 2005 10:41 pm

I am having a fight with my car. It's a 93 Plymouth Sundance with a 2.2L, automatic. When I start it cold in the mornings, and start down the road, it starts to overheat. The temp gauge slowly goes all the way up to hot and pegs momentarily and then drops quickly to cold. It does that 2 or 3 times and then runs normally all day. If I make a quick stop and then go again (warm start) it doesn't do that. I replaced the thermostat and bled the air out of the space behind the thermostat. It still does it. I took the thermostat out and ran it without a thermostat. As expected, it dosn't warm up and stays cold. That tells me that the water pump, radiator and hoses, etc are all ok. I replaced the radiator, hoses, and radiator cap this past summer. Of course I could take it to the shop, but I don't feel like paying more than the car is worth.

Any ideas besides shooting it and putting it out of its misery? All these hot/cold fluctuations is going to do it for me if I don't get this solved.

Ixolib · #2 Postby **Ixolib** » Thu Jan 27, 2005 10:48 pm

Might sound too logical, but are you sure it (thermostat) wasn't put in "backwards"? Speaking from experience... :oops:

Lindaloo · #3 Postby **Lindaloo** » Thu Jan 27, 2005 11:19 pm

If it does not do it with the thermostat out then that means you bought a defective thermostat. Another possibility is your temp gauge could be bad. Would be hard to put one in backwards on those type of cars. You could have though.

#4 Postby **TazzyD** » Fri Jan 28, 2005 2:36 am

Could also be your head gaskets though I hope it's a defective temperature gauge as that would be much, much less expensive to fix. My current vehicle kept overheating and I ended up having the head gaskets rebuilt after trying to replace the temperature gauge didn't work. It hasn't overheated since.

Lindaloo · #5 Postby **Lindaloo** » Fri Jan 28, 2005 7:49 am

Blowing head gaskets is not the same as the trouble he is having. If he had blown head gaskets the car would be running hot all the time.

#6 Postby **coriolis** » Fri Jan 28, 2005 9:32 am

Plus there's no oil, foreign matter, or discoloration in the coolant. Same for the oil - no foamy stuff. (death to the main bearings)

I find that if I let the car sit and warm up, it doesn't do it as bad. After this cold snap is over, I might just take the thermostat out for good. This car has 175,000 miles, so I definitely got my money's worth out of it. (especially since it was given to me for free at 125,000). The tranny is starting to slip and the starter is starting to slip (probably a solenoid). I'm not going to pour a lot of $$ into it.

I am definitely in the band-aid mode now, and in a couple of months I may be looking for a new used car! Besides, the buses run out here and 15 miles is not too far to bike it to work.

Thanks everyone!

chadtm80 · #7 Postby **chadtm80** » Fri Jan 28, 2005 9:40 am

Take yout thermostat out and put it in a pan of boiling water.. If it dosent open up then you know you have a bad part

weathermom · #8 Postby **weathermom** » Fri Jan 28, 2005 9:44 am

Menopause?

bjacobs99 · #9 Postby **bjacobs99** » Fri Jan 28, 2005 10:26 am

when the gauge says its hot have you checked to see if is actually hot... gauge pegged out you should be seeing steam and hear it boiling...could just be a bad gauge....maybe lost its ground

Persepone · #10 Postby **Persepone** » Fri Jan 28, 2005 11:45 am

If the car is not actually overheating (steam etc.) then it's probably a bad temperature gauge.

On 1979 VW Rabbit the symptoms you describe were chronic because there was something about the position of the overflow tube and the thermostat that made it go up, peg, and then go down to normal... developed once car was old enough (about 10 years) so that there were some sort of pressure leaks so it looked like (to sensors) there was not enough water...

On another car I had, however, it actually did overheat. But you had to run it a little while (but not very long). It turned out there was a pinhole leak in one of the radiator hoses--but you could not find the leak when the car was off because when it was not under pressure, it did not leak! Annoying and frustrating. Need to have one person look while car is on and sort of dangerous because of the fan that comes on without warning, etc. etc. etc. Parking on bedsheet, turning car on and waiting for temp light, gives you a surface where you can actually "see" if car was leaking--even a little bit.

Unscientific, but works better than driveway, etc. where you can look for the leak forever and never find evidence of it...

#11 Postby **Pburgh** » Fri Jan 28, 2005 11:51 am

Start the engine up and get it up to operating temperature and then bleed the air. Do it three to five times. If you don't get all the air out it will continue to give you a problem. Bleeding it one time does not do it!!!

#12 Postby **coriolis** » Fri Jan 28, 2005 1:19 pm

Good ideas, all!

BTY, the thermostat had a a little arrow on it to indicate the orientation, plus I put it in as per the picture in the manual.

I'll try Karan's suggestion first because it involves no cost and the least amount of work, as long as I don't get scalded in the process. I'll keep the radiator cap off so it doesn't build up pressure and spray out the vent port.

It could be a bad gauge or a short. Sometimes when I put on the headlights, the instrument lights don't come on. But if I whack the top of the dashboard, they all come on. Maybe if I drive the car into a tree....

But when it is acting up, the engine is hot, the radiator is cold, and the top hose is cold. That tells me that the guage is accurately reporting.

Yeah, time for a new car....

A car question

A car question

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