2002 P.T. Cruiser Overheating Problems?

This is a 2002. Have you had the coolant changed?

The only reason I can think of a car eating thermostats is that there is trapped air in the cooling system, and what is happening is that an air bubble is encompassing the thermostat, and the thermostat is overheating.

Are you losing coolant, even a small amount?

My last thermostat only lasted 20 months. Any ideas?

Hello Ted and thanks for the quick response. I have lost a large amount of fluids but it does not look like, or smell like, coolant. It is brackish in color and was preceded by a large amount of gurgling. I have already taken the car to the dealership and will wait to see what the consensus is.

Sounds EXACTLY like coolant to me! You do know that G-05 antifreeze used in modern Chryslers is reddish (factory fill) or yellow (aftermarket) in color, not green, right? Nothing else usually "gurgles" before leaking either.

Hello Steve,

Yeah, I knew they changed the colors. Just grew up with the green stuff and I guess it is embedded in my mind. Well - the car came back home this afternoon. It was indeed coolant. It develops that both fans froze up and the system went to crap. I live in the Phoenix area and it just over 108 yesterday.

It won't matter if it did - remember he said the car was under warranty, (he probably has an extended warranty on it I would guess) and so if the engine went to crap then his warranty coverage would take care of it. I'm sure the insurance company that underwrote the warranty would be pissed off at the "muckanics" that didn't bother to check the cooling fans the previous -three- times, but that is their problem, not his.

Ted

its a pt cruiser............JUNK

My last thermostat only lasted 20 months. Any ideas?

Don

I have read the several replies to your query. Should not the Coolant Overflow System/Reservoir take care of ridding any bubbles from the coolant system? I do monitor mine at least monthly if not more during the summer.

Bob AZ

If a head gasket is failing then the compression stoke will produce a lot of gasses going into the coolant - endless supply of bubbles.

As for trapped air - you obviously never had a fishtank with a side-mount filter that used siphon hoses to draw water from the tank.

Ted

An engine cooling system doesn't rely on a siphon. However, the OP asked why the bubbles wouldn't bleed off into the overflow tank. Normally the overflow tube is on the low pressure side of the radiator cap. In order for anything to go into that tank pressure would have to build high enough. Bubbles won't cause that.

That's not how many modern "overflow" tanks work. They are actually part of the pressurized system, and coolant is pumped THROUGH them continually. They're really not an "overflow" tank anymore, they're more akin to a surge tank on an old liquid-cooled aircraft engine, only pressurized.

I've thought I saw what I think you are referring to. They always say to add fluid to that tank and never take off the radiator cap to do so. However, the tank is still a thin walled plastic tank with a non pressurized cap. So guess I haven't seen what you're referring to!

I find my wife's 2000 Intrepid really frustrating -- if I can believe the FSM, it really does have a conventional overflow tank -- but the overflow tank and pressure tank are molded in a single piece. The only cap is the pressure cap. The "correct" way to fill it is to put on a special funnel that mates to the pressure cap fitting. The result is that there is *always* air in the system.

Hmmm... it actually looks like I could puncture the overflow side so I could fill it, and put a cork in it...

I believe both sides of the reservoir are pressurized - IOW I don't believe that the "overflow" side is vented to the outside as that would require some sort of isolation valving between the two compartments, and I don't believe their is any. I haven't understood the purpose of that funnel, and don't have or use it on either of my two Concordes (same car for this discussion as your wife's Intrepid), and have never had any problems after servicing and refilling the coolant system.

The idea is that the coolant continuously circulates thru the pressure chamber (when the engine is running) and any air in the system will find its way there and be trapped there, so the rest of the system is air free. There is a bleeder valve in the intake area that is supposed to be open when refilling to prevent air being trapped in the block during refill. Any small amount of air will then make its way to the reservoir when the engine is run in normal subsequent driving.

I guess the FSM doesn't actually say the overflow chamber isn't pressurized -- but it refers to the other chamber as the "pressure chamber", and the path to the overflow chamber is by way of the radiator pressure cap.

I've never had any actual problems, either. It just annoys me.....

No, the kind I'm referring to can be found on first-gen LH cars, for example. Thick-walled plastic WITH a pressure cap ON the plastic tank, and no other radiator cap.

I *think* the PT uses the same type, but its been so long since I've looked under the hood of a PT that I don't remember.

Hmmm.... no bleeder on the T-stat housing on 2nd-Gen LH cars??

Other than the fact that the bleeder is so nearly at the same level as the overflow tank that it takes too long to force the last of the air out of the system, I have no complaints with the first-gen system. I had expected that pressure tank to promptly explode when the warranty expired, but here we are 15 years and 250k miles later, still going (knock wood).

No, the bleeder is there (though the thermostat has been moved away from that housing to a location down on the side). My annoyance is that I find it nearly impossible to see the level of the coolant in the pressure tank due to the tank being nearly opaque and the dye being very light in color; I can only check the level with with any confidence with a cold engine.