My PT cruiser overheating.. HELP!

[samiejg]

Hi Guys,

Since I've had a 2002 PT cruiser, it's always appeared to have a slow slow slow leak coming from it. A mechanic once said to us that appears like it might be leaking is the water pump. It's nothing serious though. I just have to top it up every month or two. Same with oil.

Two days ago the car (conveniently the night after I put water in it with my new garden hose + overfilled the reservoir because I couldn't see how full it was and the GF told me it wouldn't matter) overheated on me. It seems fine if the heat is on full blast, but otherwise it won't even run for 3 minutes usually.

The reservoir is still overfull. But I had to put water into the radiator, which is where I mostly have to put water anyways.

I watched under the car for a while and there doesn't appear to be any leaks. Afterwards I took the car for a quick drive and let it overheat, and THEN checked and it looks like the water is only coming from the reservoirs overflow presumably because the reservoir keeps boiling every time the car overheats.

So I'm guessing when the water starts overheating, water from the radiator starts making it's way to (and out) the reservoir for some reason?

Now I'm trying to figure out why the car is overheating. I checked and made sure the fan infront of the radiator is on and it does appear to be working. I dont think there's any other fans to check.. ?

I took the front of the car apart and checked between the AC and radiator to make sure it's not clogged up with leaves and it clean.

I heard some stuff online that the thermostat could be stuck closed. Not sure if I tested this right.. But I felt around to all the hoses and they seem pretty hot, and I would think if it was shut then the radiators water wouldn't make it to the reservoir, correct?

Lastly, I tried bleeding air using the little valve beside the thermostat.

I haven't put the car back together yet to test it. Just have a feeling it's not going to work and thought maybe I would check with you guys here to see if you had any other ideas or things to check for before I put it back together.

My GF and her dad both told me right off that bat that it must be the water pump acting up and to change it. But they haven't even looked at it, they're just going by what the mechanic said a while back about it having a tiny tiny leak(which still seems to be the case). I wanted to check around first before getting into such a big job, since I know it's common for people to start getting into replacing everything on their yet still have no success.

[CREWZIN]

Welcome to the forum.

You didn't say what your mileage is but if it's anything around 100,000, the timing belt should be changed and along with that, the water pump and belt tensioner should also be replaced. Both wear out like the belt. So if your at high mileage the water pump could be at fault for the overheating.

The other two main reasons for overheating are air trapped in the system and the radiator fan that's not working properly. Loosing any water lets air into the system which lowers the boiling point. The radiator fan has two speeds and the PT has a tendency to have one or both speeds burn out. One test is to turn on the A/C and see if the fan comes on. The fan should run when the A/C is turned on. If not, things heat up rapidly to the point of overheating.

[jjackson23]

What is the mileage on the car? The water pump should be changed when the timing belt service is done as most of the labor required to change the part is the same. The timing belt should be changed at 100,000 miles intervals, although I've heard of them failing at 80,000 or less. The PT engine is interference meaning if the timing belt fails while driving at speed the engine will be damaged. The normal culprit for overheating on PTs is the radiator fan module. The fan has two speeds so even though it seems to be working it could be that low speed is working and high speed is not. Easiest way to check the high speed fan is when the car is cold turn on the AC. You should hear the fan start even though the car is still cold. The other possibilities could be the following:

• thermostat
• radiator blockage or failure
• temperature coolant sensor

[CREWZIN]

HOLD ON THERE JJACKSON23. The PT is a NON-INTERFERENCE engine. Only if your at high speed when the belt decides to go will you have a chance of any internal damage and that would be the opposing vales MIGHT hit each other. That's all. Of the hundreds of PT owners that have come to the forum for help when the belt goes, maybe 1 or 2 have ever seen any kind of damage so the odds of any internal damage is extremely low.

[samiejg]

Originally Posted by CREWZIN

Welcome to the forum.

You didn't say what your mileage is but if it's anything around 100,000, the timing belt should be changed and along with that, the water pump and belt tensioner should also be replaced. Both wear out like the belt. So if your at high mileage the water pump could be at fault for the overheating.

The other two main reasons for overheating are air trapped in the system and the radiator fan that's not working properly. Loosing any water lets air into the system which lowers the boiling point. The radiator fan has two speeds and the PT has a tendency to have one or both speeds burn out. One test is to turn on the A/C and see if the fan comes on. The fan should run when the A/C is turned on. If not, things heat up rapidly to the point of overheating.

The cars got 200,000 on the meter but I bought the car used and I've only had it for a little over a year, so not sure if they've ever been changed before or not.

I never knew that about the two different speeds for the fan. Will the test still work if my AC doesn't work? If not, is there any other tests I can try?

And if the fan is working fine, do you think I should just buy the water pump and do it anyways even though there doesn't appear to be a leak? (atleast it doesn't look like it to me..)

[samiejg]

Originally Posted by jjackson23

What is the mileage on the car? The water pump should be changed when the timing belt service is done as most of the labor required to change the part is the same. The timing belt should be changed at 100,000 miles intervals, although I've heard of them failing at 80,000 or less. The PT engine is interference meaning if the timing belt fails while driving at speed the engine will be damaged. The normal culprit for overheating on PTs is the radiator fan module. The fan has two speeds so even though it seems to be working it could be that low speed is working and high speed is not. Easiest way to check the high speed fan is when the car is cold turn on the AC. You should hear the fan start even though the car is still cold. The other possibilities could be the following:

• thermostat
• radiator blockage or failure
• temperature coolant sensor

Don't think it's the termostat because all the hoses seem to get hot. I checked the radiator and there's no blockage. I guess maybe it could be a failure but I'm not sure how to check. Also not too sure about the coolant sensor.

I'm going to try that AC thing in a bit, but I'm not sure if the test will work anyways because the AC is broke. Any other ways to test it?

[CREWZIN]

Testing the fan...

[NitroPT]

Welcome to the forum

[NightWing]

Only small amounts of distilled water should ever be added to a radiator. Proper coolant resists boil over much better than water.

The way the overflow bottle works is, when the car cools down, coolant is siphoned from the bottle into the radiator. When the coolant heats up, any overflow from expansion goes back in the bottle. You will notice two levels marked on the bottle, cold and hot, indicating the proper level for either circumstance. The bottle should not be totally full or totally empty.

If you are going to go through the trouble of changing the water pump. by all means, change the timing belt, tensioner, cam and crank seals. The parts are relatively cheap but the labor is intensive and costly.

[ptcruisersteve]

First I would suggest checking the hose between the radiator cap and the overflow tank. If its leaking it will allow air to get into the coolant system.

Second I would suggest you have a coolant compression test done. You need to make sure there is no leaks in the coolant system for it to work properly. Check to see if you have coolant coming out of the bottom of the engine when the coolant pressure test is done.

If there is no leaks in the coolant system I would suggest checking the radiator cap. You need the proper coolant system pressure to keep the coolant from boiling.