03 Overheating

[Cruisjim]

My 03 is overheating. I have had the radiator flushed out. That did not fix it. Changed the t-stat and it still overheat. The problem is that it overheats driving down the road on when it is stopped. Does anyone have any ideas?

Jim

[CREWZIN]

Jim,

Too many questions to ask so I'll just let you read through some of the old posts to see if they will help. There's more if you so a search on "overheating".

Yes another overheating question.

PT cruiser Overheating - fan isn't running

02 PT overheating?? grr...

Cylinder miss and overheating

PT OVERHEATING!!!PLEASE HELP

Back with another over-heating prob...

PT Overheating at idle

Overheating PT!

[Cruisjim]

I am beginning to think there may be a problem with the high speed fan setting. The fan only comes on when it reaches normal operating temp (1/2 way). Then when you turn on the A/C, the fan runs at the same speed even when it goes up one more mark. The fan comes on when very the A/C is on. I have checked for air in the cooling system. I left the radiator cap off ran it until the t-stat opened up. it had good flow. I watched it for about 20 min. The coolant level remained full with no air. What is strange is it gets hot as you are traveling.

[CREWZIN]

You might have to take it to the dealer or a mechanic that has a scanner to find out way the high speed of the fan isn't coming on. It might be just the high speed relay, the PCM or the fan motor itself.

No fan should be running once the PT reaches 35mph. The computer turns off the fan as there should be enough air coming through the condenser and radiator to keep everything cool. If yours is still getting hot when your running along at above 35mph then the air isn't getting through or the coolant isn't being allowed to circulate freely.

[Cruisjim]

Well today the radiator fan will not come on unless it is jumped. Also, the a/c compressor is not coming on.

Jim

[Cruisjim]

Is there something that controls both the fan and the a/c compressor?

Jim

[CREWZIN]

The fan is controlled by the coolant temperature sensor, relays and the PCM. The compressor comes on when you either turn the A/C control on or switch the control to defrost but is regulated by the high and low pressure switches and probably the PCM also. The PCM would probably be the only connection between the two.

[Cruisjim]

Where is the PCM located and is there anyway to test it? I am a little frustrated, we just spent $2000.00 on the transmission and now it is overheating.

Jim

[CREWZIN]

It's located in the engine bay right on the firewall in front of the driver. The only way to test it is with the proper scanning tools.

Did it start overheating right after they fixed the tranny? They very possibly did something that started the overheating process and you can't prove that without finding the reason for the overheating. You might call them up (is it a Chrysler dealer) and ask if they can check over their work to make sure everything is back the way it was before the tranny was fixed. Just a thought.

[Cruisjim]

No the work was done at a transmission shop. I don't know of anything that they could have done that would have caused it. I do have a code reader.

Jim