Hope I solved overheat prob.

[Arne]

Firstly, hello all, I am a double PT owner.
It's easier to figure stuff out when you have two.
They are both non turbo 01 auto, air, base package.
Overheated my white one when driving city with AC on.
Replaced thermostat, cap and radiator even though I have only
50k on the car. Still overheating.
No smell at exhaust, no bubbles in radiator no sign of oil contamination.
I was about to delve into a head gasket replacement when I noticed a small
problem.
I don't blame anyone if you find this laughable or incredulous, but,
the cheap rubber PCV tube was mush and collapsed. I had taken care of this a long time ago on my wife's PT and forgot about it.
Guess what I found... No More Overheat... so far.
I'm about to give it a hot day test but it has held normal dead steady with full AC.
Woo Hooo.
Jim A.

[CREWZIN]

I hope your right Jim, but the PVC tube is only there to recirculate the exhaust gases and create less pollution. Shouldn't have anything to do with overheating. You are talking about the 5/8" tube with the PVC valve on one end and the tube attached to the upper intake on the other, right.

[Arne]

Yes, there are two tubes very similar right next to each other.
The airbox filtered tube is ok, but the one from manifold to valve on cover was closing off vacume from the crankcase.
I agree with you that this would not be a big thing on other vehicles where I've seen it,
but I believe this cooling system is very minimal and the computer settings didn't like that restriction.
Since I mentioned it,
I heard recently a rumor of a computer flash update having to do with some issues.
Since I carry a spare computer I wondered if it was worth a try at having it reprogrammed?

[CREWZIN]

I have an 01 automatic with 100,000 miles and only had 1 computer flash lots of years ago. You can take you VIN to any dealer and they should be able to tell you if yours needs one.

[quicksilverdon]

The PCV hose needed fixing, but agree w/Crewzin, can't see it causing overheating...
Was the car idling poorly?
I hope you're right...

[Arne]

Hey quicksilver Crewzin was correct.
She overheated again.
It gets me that there's no indication of any other symptoms.
I had one tip to remove the low fan relay as a test. Not sure where I saw this but the fan was supposed to then default to high speed mode.
When I tried it it didn't help so both relays are in and fan does come on.
My limitations start when it comes to head or pump removal.
So I'm almost at the hands of a dealer.
I'll dick around a little further, because it is actually the air conditioner that's
putting a load on things.
Sorry to appear to get anyones hope up and I appreciate the remark that an expensive repair equals 4 payments.
Helps me put it in perspective, and I'm blessed to have other vehicles just in case.

[CREWZIN]

Jim,

How about the simple things like making sure all the air is bled out of the system and that your thermostat is working and are you sure that both speeds of the fan are working.

[Arne]

Thanx, you give very good advice.
I am going to disassemble the squirely front fan and clean and restore it.
One thing of interest about the larger relay for slow speed.
It opens easily by lifting its lid. Once you access the contacts you can watch it pick or manually engage it for troubleshooting.
It is delicate inside but the cap easily snaps right back on.
The front and rear contacts I believe are the make connections which helps because unlike the smaller relays they are unmarked.
I would have that fan in my hand right now if the mosquitoes had left my ankles alone.

[Arne]

This fan motor has 50k on it under hot conditions.
Found it to be completely full of graphite with brushes almost gone and armature appears to be missing almost an eight of pads.
Replacement at 100 bucks is arriving tomorrow because brush assembly is one piece design.
I would not have thought to go into this without you guys so thanx again for good advice.
The other PT is closer to 100k on it and I'm wondering if that fan has any life left?
The Silver PT had developed a small crack in the radiator upper tank near the top inlet above the seam.
I saw it in time and JB Welded all around the area about three months back.
Still holding pressure but it took two applications to get the entire crack.
Antifreeze is like blood, in that you'd rather not let it spill out.

[CREWZIN]

Originally Posted by Arne

Antifreeze is like blood, in that you'd rather not let it spill out.

It also needs changing (not like blood) every couple of years and refilled with the correct replacement fluid. Good luck with the fan, hopefully that WILL be the underlining cause of your overheating.