Overheating Diagnosis

[Gomanngo]

I have a 2002 PT Cruiser which has started to experience some overheating problems. After some internet research it seems that this is not an uncommon problem with PTs, particularly my year. I have read and read how multiple thermostats are changed, fan motors, relays, etc.

Approximately one month ago I was out of town and overheated. A local mechanic found the problem to be a cracked thermostat housing. So that was replaced along with the thermostat. Works fine for several weeks and begins overheating again.

Took it to a local shop and this is what I was told ...

Motor mounts wore down enough to allow the engine to rock enough to impact the air conditioner which impacted the fan.

This seems logical to my non mechanic mind processes, as one of the overheating conditions would be when I braked. Almost immediately the temp would rise (motor going forward) ... not anything like sitting at idle with no air. Additionally, when I acclerlated (thinking motor swayed back) the temp would almost immediately decline. I am almost positive this was not due to airflow going through the wall of the radiator, a reasonable assumption, because my car would continue to overheat on straight aways going between 60 to 70 ... even with turning on the heater.

Thoughts?

[Knotsobright1]

Uh...

I would suggest checking the radiator first. My 2001 just went thru the exact same problem. The radiator failed causing our PT to overheat. It would sit and the half point and then sky rocket whether driving or not. 1 way to check is to take a little drive and once it reaches half shut the engine off and CAREFULLY check the radiator. If it cooler on 1 side and hot as on the other the radiator is bad. I personally have never heard of overheating caused by bad motor mounts.

Actually if it declines once you speed up then your fan is going out. The fans shut off at 35+ mph. As they are no longer needed.

[CREWZIN]

Originally Posted by Knotsobright1

Uh...

I personally have never heard of overheating caused by bad motor mounts.

Actually if it declines once you speed up then your fan is going out. The fans shut off at 35+ mph. As they are no longer needed.

[Gomanngo]

I thought I would come back an update my thread, since higher temps seemed to be causing many overheating problems.

After the mechanic quoted me replacement of the motor mounts and fan and started to fully disassemble to install parts he found another problem. Supposedly the radiator needed to be replaced. According to him, it had a leak. I was a bit suspiscious, because it was one of the things that I was diligent about in checking. The fluid level never dropped and I never left any puddles.

A few hours later, another call. This time I was told that some framing was bent. He said what he thought the motor mounts were causing, was actually the framing being bent. He asked if I had hit anything recently, which made me very upset because I hadn't and thought he was being shyster. After a little more discussion, he rephrased his question and asked about pot holes. I live in rural america and pot holes are a part of everyday life. He said with the PTs being so low and their frames so light a hard enough hit could cause this issue.

So I back track to the point of when I replaced the cracked thermostat and a day before I was traveling an unfamiliar country road. They were doing some development and tore out the asphalt creating a sudden four to six inch drop. No signage, no familiarity and going 55 mph partnered with the light frame and how low PTs are ... it was a big hit.

After sharing that with the mechanic, insurance and adjuster, it seems that this is what did my cooling system in.

Thought I would share here so others may take a look at their ongoing overheating issues to see if this may apply to them. I am very happy that I will be getting a whole new cooling system, considering the overheating issues I have read about, for only my deductible.

And FWIW, I mentioned to the mechanic to make doublely sure that my head/gaskets are intact and that no damage was done due to the overheating. I was very careful not to exceed the 3/4 point on the temp gauge, but you never know.

[Travis2k7]

Originally Posted by Gomanngo

He asked if I had hit anything recently, which made me very upset because I hadn't and thought he was being shyster. After a little more discussion, he rephrased his question and asked about pot holes. I live in rural america and pot holes are a part of everyday life. He said with the PTs being so low and their frames so light a hard enough hit could cause this issue.

Unrelated, but a friend at work has an '01 PT and he hit some 18 wheeler tire debris on the Interstate once... busted the oil pan and lost all the oil.

He told me he didn't realize it until the oil light came on... immediately pulled over but it was too late and he lost the motor.

Because of that story I pay particularly close attention to pot holes and road debris.