Continuing with the overheating issues...

[2k1PT]

So I have a continuing problem with my 01 PT overheating.

I have had countless pressure tests preformed, and there are no leaks. I have had the thermostat replaced about a year ago, and I have had the radiator fan replaced, and found later that the plug was disconnecting so have been able to repair that.

Well we overheated again yesterday. I know the fan works because when I turn the A/C on the fan is running. At this point I am at a loss.

I was looking thru the Haynes manual I have for it, and am thinking about the following , but wanted your suggestions before I go and buy these parts.

First, I am not sure if the low relay is working properly, so I was thinking of just replacing both relays with brand new ones.

Also I am thinking of replacing the thermostat just in case it is getting stuck due to all the overheating I have been having, and I read something about the engine cooling sensor (which I assume has something to do with controlling when the fan is to start).

Would these be something that could be causing a problem and a place to start?

I cant think of anything else it could be that is causing this problem.

Thanks...

[CREWZIN]

Other things are the radiator itself could be partially blocked/clogged. The radiator cap could be bad and you could have trapped air in the cooling system.

Are you sure the fan is coming on high speed when needed?

[2k1PT]

Originally Posted by CREWZIN

Other things are the radiator itself could be partially blocked/clogged. The radiator cap could be bad and you could have trapped air in the cooling system.

Are you sure the fan is coming on high speed when needed?

Well I know the fan is coming on when the A/C is switched on (which I believe works off the high speed relay correct?), so I am assuming it is coming on high speed.

Is there any way to check for a clogged radiator? The cap was replaced last year when the thermostat was replaced (I believe the rating on the cap is 16).

[CREWZIN]

No, the fan coming on with the A/C isn't necessarily the high speed. Mine comes on low speed and when the temperature raises, then the high speed comes on. When the high speed does come on it's VERY LOUD. Way above the noise of the low speed and above the engine noise. You can't mistake it.

The radiator would have to be taken out and cleaning fluid and force fed high pressure water. Is the coolant red? Is there any rust color in it? If it's not redish color you have the wrong coolant. Recommended to not hurt/rust out the insides of the radiator is HOAT coolant with 50.50 mix of distilled water.

[vtmdsm27]

Ditto. High speed fan is very, very loud. Daughter had these problems. Replaced the entire fan motor assembly (on national backorder, so that is an indicator). A year later we replace a switch. At one point, the mechanic thought we'd need to replace the TPIM, but that turned out to be incorrect.

[mdfrodolives]

Check to see if your upper radiator hose is getting nice and hot after warming up your PT to normal-running temperature. If it's not, then your thermostat is not opening ....

[2k1PT]

Well I think we found out this time was the fan. The plug keeps coming lose, so since this has been an ongoing problem, we just took the plug ends off and hard wired the fan in....

so far so good.

Does the cleaner stuff you can put in the radiator of any real use? I was going to put some of that in there.

And no, my fluid is green. I had asked the auto shop about the difference, and they are claiming there is no difference in the type of fluid they sold me (the green) and the reddish color. Can this be causing a problem, or is it just something that will be an issue in the future, as I am hoping to get rid of the car within the next year so I am not too worried about future issues.

[CREWZIN]

The green stuff, if not HOAT or equivalent might eventually cause the radiator to rust up or clog up. Ask to see the container.

[ivynthemnts758]

change the temp. sensor it is a cheap part and very problematic if it is bad..

[hyltoto]

It is my conclusion that inoperable radiator fans are the big culprit in the overheating issue, because at highway speed you don’t miss it, but in city traffic you will miss it big time. Coolant flow is easily checked by heater operation. I learned here that you can check the fan operation at hi speed with the ac being set on, but no check is available for low speed radiator fan operation without some disassembly.

Thank providence for this thread. The things I learned here saved me a lot of aggravation finding the cause of my overheating issue. I have a 2002 Limited with 118000 miles. This summer it would start overheating when I stopped in traffic, the turning the heater on trick kept me from being stranded however, and assured me that the water pump was circulating coolant. After reading your threads I purchased a Hayes repair manual for 2001-2003 cruiser from Amazon to better trouble the engine temperature control system unique to these years. I change the relays because they are cheap. The radiator fan still would not operate so I decided to pull it during Labor Day and replace it. I checked defective on both speeds so a replacement was necessary. I would have changed it anyway after reading the horror stories. I ought an aftermarket from Amazon as well.
The replacement was somewhat warped but functions fine. I drove the vehicle to the local carwash to blow out the radiator fins with the pressure wand before replacing the grill. I could feel the air being sucked thru the radiator.

My air conditioning hasn’t functioned for a while, but the coolant might have been purged by overpressure during one of the overheating events. Got 9 months to play with that issue.

This was the most convoluted vehicle to work on I’ve ever experienced. The most prominent tools in this repair were my tactical flashlight, finger tip ratchets, and wobble extensions. Thank you Harbor Freight.

The Hayes manual is ok, but does not give bolt sizes, they are all metric by the way, and overlooks a screw behind the relay and fuse box during removal instructions to reach the egr valve.

I did get a maintenance schedule and found I need a new timing belt. Mechanics around where I live refuse to do that job unless the water pump is changed simultaneously. We are talking about $7-800 bucks. For comparison I had the same job quoted on my sons Focus and it was $265.

This experience is not conducive to another Chrysler product purchase.