overheating after changing thermostat

[kimberlirenee]

I reciently bought a 92 lebaron and was told that the thermostat needed changed. well i did so and it has only been a week and now it is overheating, what could be the causes of it or what should i do to fix it?

[blaster1812]

I'm on the same boat as you. Just replaced the thermostat in a 90 Lebaron as it was blowing cold air and when i went to replace it the thermostat it was installed upside down with the spring facing up. Thinking this was the problem, I installed the new thermostat with the spring facing down with a new gasket. Took it for a test drive and the car's heat gauge goes full. Anyone know anything about this problem? It's in the 3.0 Lebaron.

[4pt9fiero]

Question for both of you - did you use an OEM part or an aftermarket replacement?

There are alot of cars out there that you can get away with an aftermarket, and perhaps someone else will chime in here, but I had a similar problem with my 92. It had a stant replacement, went to autozone and replaced it with there generic brand - don't remember exactly what - still ran hot.

Went to the stealership and $38.00 later I had an OEM - guess what - NO MORE PROBLEMS!!!

P.S. - I had the same exact problem with an 89 sentra I owned only the OEM thermostat only cost $29.00.

Good luck

[blaster1812]

Originally Posted by 4pt9fiero

Question for both of you - did you use an OEM part or an aftermarket replacement?

There are alot of cars out there that you can get away with an aftermarket, and perhaps someone else will chime in here, but I had a similar problem with my 92. It had a stant replacement, went to autozone and replaced it with there generic brand - don't remember exactly what - still ran hot.

Went to the stealership and $38.00 later I had an OEM - guess what - NO MORE PROBLEMS!!!

P.S. - I had the same exact problem with an 89 sentra I owned only the OEM thermostat only cost $29.00.

Good luck

Ye i used a "Motorad" or somthing along that line brand. I tested it in hot water and it never opened so i'm gonna go to the dealer and get an OEM one.

[kimberlirenee]

im not sure what kind of thermostat i got but i think now that my water pump froze up and caused the thermostat to stick. now i was able to get parts from another store and i am working on getting it changed, i now have a stant thermostat and i dont know what brand my water pump is but i am going to clean the radiator out to ensure that things arent going to get gunked up so all said and done i was very LUCKY because a guy i know deals in parts and he was able to get me my parts CHEAP but the at same quailty as full price, All toghther i have spent (this time around) 31.49, (2.99 for the thermostat, .75 for the gasket, and 21.99 for the water pump) so we will see how this goes.

[sundownsound]

Sounds to me as if You have a Vapor lock poblem. Air gets trapped in the thermostat neck and fluid wont move. You have to have the front of the car higher that the tail and squeeze top hose repeatedly while filling to "burp" to air out. there ia also a plug w/ allen head on side of housing you can take out... sometimes...they corrode in! no kidding,I had this same problem. Google it and check it out! Good Luck!

[michaelchristian]

I've got the same problem. Replaced the thermostat, water pump, and timing belt, but still overheats. Think an OEM part could solve the problem?

[KManiac]

Hey MC:

What engine do you have and how many miles?

[michaelchristian]

The 3.oL v6, and about 120000 miles.

[KManiac]

Hey MC:

Now for the next questions:

When your car overheats, does the temp gauge go from lowest C to full H within the first 5 miles from being started cold, or does it slowly climb to full H and take more than 20 miles of driving to do it?

Also, when the car overheats, does the radiator and upper radiator hose feel hot or cold to the touch? (WARNING: Don't touch a hot radiator or radiator hose. Placing your hand within 1/4 of a hot radiator or hose will tell you whether or not it is hot, without touching.)

Anyway, let us know the answers to get to the bottom of this.

[michaelchristian]

It usualy takes more than 5 miles, but not much more. I think I might have narrowed the problem down to the timing being off. Do you know what the timing on the 3.0L SOHC V6 should be?

[KManiac]

You forgot to answer one of my questions, and a very important one, at that. When your car overheats, is the radiator and upper hose Hot or Cold??

I think I know what your problem is, and I don't think it's mistimed. your answer here is crucial!

[KManiac]

Well, since you didn't answer my last question, I'll just put my two-cents worth into the mix as food for thought.

Many of the modern thermostats do not have a weep hole, to allow release of trapped air behind the thermostat. Thats why it is important to bleed out the trapped air inside the engine block when you refill the cooling system. If you don't, the temperature gauge will peg out to full hot before the thermostat opens the first time after refill.

Now, there is another condition that allows the entry of gases into the cooling system. If you have either a cracked head, cracked cylinder wall in the block or a bad head gasket, you can get exhaust gas intrusion into the cooling system. When this occurs, a bubble of exhaust gas collects behind the thermostat when you shut it off. Then, the next time you start it cold, the temperature gauge will peg out in the first five miles before heating the thermostat enough to open it. This symptom mimmics a stuck thermostat or a cooling system improperly bled of bubbles at refilling.

Now, if you replaced your thermostat because you thought it stuck shut and now find the same symptom has returned, your problem is most likely a cracked head or block or bad head gasket, or a combination of any or all.

Try this: Remove the thermostat and drill a small (1/16 or 3/32 inch) weep hole in the metal plate, then reinstall. Once the engine reaches operating temperature, check for the presense of bubbles percolating from the bottom of the coolant overflow tank. If you spot these bubbles, go to your local auto parts store and purchase a "Universal Block Tester" kit. Use this kit to check for exhaust gas contamination in the cooling system.

What I just described is what I experienced with my Dodge Shadow two years ago. Found the problem was four cracked exhaust valve seats. After a head rebuild, the car runs like new again.

Let us know what you find and what you do.

[nortoncommando]

[quote=KManiac;5013602]Well, since you didn't answer my last question, I'll just put my two-cents worth into the mix as food for thought.

Interesting, I have just replaced the thermostat on my Le baron, problem remains. The old thermostat was definitley useless, engin overheats in the first few miles, upper hose remaind less hot than engine. Cracked block?

[nortoncommando]

..............is a ceacked block repairable? I think thats the cause here