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01 PT Cruiser Running Hot/Overheating

07-23-2008, 04:41 PM
I'm not mechanically inclined, so I'll try to keep this short, but as detailed as possilbe. 2001 PT Cruiser (4 cyl) 140,000 miles.

It's been hot here.. and days around 90 or higher are MUCH worse. Temp guage normally points "half" way. Lately, it starts rising higher to almost 3/4 at times if I don't turn the heat on to pull hot air off engine. Even mid 80s in temps seem to have an affect.

Last year I had timing belt replaced, and for the first time after that, car overheated and shut down twice (and AC wouldn't work at all after belt repair either). Did a drain and fill, and car was fine.

This summer, even on cool mornings (around 75 out) after 45 min drive at 65MPH and about 2500rpm the temp guage rises after I get off interstate. I did another drain and fill (the invoice said drain.. not flush) but it did not help. I also bought a new radiator cap (16lb pressure) and checked and the radiator is full, no leaks. Coming home, it does ok first 30 min of drive, but once I start hitting a few hills, the temp guage starts to rise.. sometimes a little, other times almost 3/4th of the way towards "hot". This past weekend driving home from a trip, (about 3 hour drive time) it was around 90 out, and I could not use AC or temp guage went way up, and even with vent on I had to have heater on at about 80%(high) just to keep the temp guage down. If I didn't have the heat on the guage kept creeping higher and higher towards the red. I have not just "let it go" to see if it will totally overheat and shut down..

I don't mind driving without AC, but even with it on vent, on days it's hotter than 90 driving with hot air on sucks.

Few details: When I get to a stop light it goes up a bit, but if I give it a little gas in neutral (raising idle) it goes down slowly. If I'm just driving in town at 30 mph the AC still causes the guage to rise quite a bit above "normal". The hills I talk to are not "really steep", but I know they do affect it a bit like any car.. but don't think they should spike the guage 25% higher after a short one minute climb. Before I got timing belt replaced it never did this. The "fan" does kick in, I can hear it when testing. I tried to "bleed out" any possible air bubbles and didn't notice any.

I've read LOTS of people talking about cruisers and changing thermostats, hoses, etc. with no luck. Is this just a cruiser problem I deal with, or any other ideas? If one plug was bad could it be making the engine work harder without me noticing? (There is no noticable difference in sounds or performance right now other than the temp guage trying to make it to the red.) Last year it overheated quickly.. this year it's slow enough to notice and prevent by cranking up the heat.

Any ideas, suggestions, are welcome. Thank you all for your time.

07-28-2008, 01:21 PM
Hi Alex. I think I may be less mechanically inclined than you, but I'm having the same problem with the same car- same year and all. I don't drive much, so I haven't really been motivated to get the car fixed, but I was wondering if I might be able to ask you a few questions so I don't have to reinvent the wheel, as it were.

Are you putting a mix of water and coolant in, or is it straight coolant? Someone told me a blown gasket could cause the engine to overheat- said you could check that by checking the oil a good while after it's been changed and you'd expect it to be a bit dirty looking. If it's cleaner than you'd expect, could be an indication that water/fluid is mixed in with the oil and you may have a blown gasket. I hope that's not what I have...:uhoh:

07-08-2010, 01:59 PM
Sounds like the electric fans on the radiator are not coming on.

07-18-2010, 01:56 PM
Yep I have a 2002 and that was my prblem. One of my fans wasnt coming on..Had to get it fixed.

09-02-2010, 01:01 PM
I have a 06 Pt Cruiser and I had to replace the radiator fan twice. They are $100 but a booger bear to put in. I got a warantee on this one.

03-26-2011, 04:02 PM
two weeks ago bought a 02 pt and today the ac was hot so i turned itr off and then the car got hot so i pulled over a while then back on the road and thirty minutes later it got up into the red i pulled over and water started pouring from the bottom of the car... got it towed back to where i bought it and they said they will let me know on monday.... today is sat.... and by the way a week ago my kid ran over a mailbox hit the concrete sidewalk breaking a rim.... could that have contributed to this??? tow truck guy said it sounded like the water pump or thermostat was going slowly from what i described...

08-09-2011, 04:39 PM
My PT is one of the first 100,000 built in 2000. It has 146,000 miles on it. The problem of overheating started simple and got bigger. I did a 20 mile trip one day in July and had bubbles coming up in my coolant recirculation tank.
Decided to drain the cooling system and put some chemical flush in with a light, -10 degrees Fahrenheit, coolant mix in. I had an 80 mile, one way, trip to make the next day, and thought it would be about the correct time and distance to work the flush. Got where I was going fine, but had to stop every 10-15 minutes of driving for about 30-45 minutes to cool down and put water in.
I should have paid closer attention to what happened next. I installed a back flush kit and ran water through the engine cooling system. Water was coming out the petcock, but not out of the filler neck above the thermostat.
I took the car to a radiator guy with 40+ years in the business. He checked the system and pronounced it good by the test he could run. I took the car home and didn’t make it back to the house before overheating. Took it back the next day and he had to run the car for 45 minutes before it started bubbling, and he confirmed the fact it was CO.
This means either a cracked head or a leaking head gasket. The maintenance cost with parts would be $1,500 to $2,500. That I do not have.:crying:
I went to the parts store and got some Bars Leak HG-1, pricy but worth every penny. It has now been over 4 weeks since this started. I had a week and a half trip that I couldn’t get out of.
On Saturday, last week, I was trying to get the filler neck and thermostat body off, and I lost a bolt where I could not see it. If you have never taken the front e3nd of a PT apart, be patient. I drained the cooling system and saved it to put back in. When I finally got the radiator out I found that there was still coolant and other stuff in to top end of the radiator. Remember, this is the first time I have ever had an overheat problem with this car. I turned the radiator over and poured out about a pint and a half of coolant and other stuff. Hooked up a hose to the bottom fitting of the radiator, and turned it on. Slowly water started coming out the top, and then it came out faster. This is when I remembered the water not coming out the top of the filler neck. After you have taken down the front end of a PT you will understand why I did what I did next. I went to the parts store and bought a new radiator. By the way, I found the bolt with the help of a friend.
It is all back together. There were 2 problems. First the radiator was not allowing the coolant to circulate properly. Second, when the head overheated, the head gasket leaked. Funny thing, when 5,000 degrees of heat does not have coolant running constantly next to it, it wants to melt or expand things.
:p Good things do happen when you overcome your lack of memory, and there is a parts store near by with a new radiator, and HG-1.
If you PT or other Chrysler 4 cylinder is overheating, try to back flow some water through the radiator before you go and spend $2,000 on head work.

08-10-2011, 11:05 AM
Nice a thread from 07-23-2008. I hope he did wait for you to reply.

01-25-2012, 06:59 AM
I know this thread is old but the first thing you should do if you think your PT is running hot is to check and see if the fan will run with out the air conditioning on. That will let you fan only run on the low setting.
If it wont run, the fan is bad on the low speed, or you have a bad conection for the fan motor. That is the #1 reason for a PT to over heat.

On the other side, if your air conditioning blows warm air 9 times out of 10 the High speed side of your fan is burned out or you have a bad connection in the fan connector. The high side of the fan only runs when the AC is on.
Most times to chech this really fast is to run the car with the hood up and turn the AC on. You will hear the fan speed up. The sound is quite noticeable.

01-25-2012, 02:35 PM
Chigger, thanx for the tips.

02-14-2012, 01:10 PM
Our PT cruiser is having an issue also.when we are rolling at 25 or faster it stays cool.if we idle for about 30-45 secs it starts to over heat. when we shut the car off the coolant starts to bubble into the over flow and spews out of the drain line. the issue has came and gone since Christmas. we did not see it again untill about a week or two ago. and also an added note (maybe nothing to do with this issue) but when the car is off the heater fan will kick on and blow about every 45 mins for 4-5 secs then shut off. i am sorry for posting on an old feed just seems you guys have a good head on ur shoulders lol. we do not want to go and spend a ton of :2cents: and this is about to rune our day to day life :runaround: ty in advanced for all the help.

EDIT: also i hear the fan run when the hood is up but i am not sure it is running when it should. it kicks on right when the car is started so i am feeling the fan modual is the bad boy in this.

06-12-2012, 07:15 PM
Yeah, I def have the same problem as the OP, other than the mileage being half of what his is, and no major maintenance has been done otherwise.

This problem just started the other day. Going to start with a flush and fill, and go from there. I will let you guys know if I find anything, as OP did not report his findings, or solution. From reading this thread, there are a couple of things to check first.

Any help would be appreciated,


The thermostat could be the issue but there are a couple of things that I feel should be examined before
plunging in and only focusing on the thermostat.

The problem could lie with the fan itself, low speed relay, or an electrical problem. The question is what, and how do I proceed? Here is the problem in more detail

When you turn A/C on low, the fan will come on as it's supposed to. When you increase the A/C speed, the fan speed does increase as it should. The fan works on high and low speeds just fine. The problem is that the fan only works intermittently. When it works, it works fine and stays that way until the car is turned off. Sometimes when you turn the car on, the fans do not come on at all, no matter what speed the A/C blower speed is on. I can simply turn the key off and back on, then turn the A/C on, then the fan will be working again. Seems like 50/50 and I have no idea what causes it to work or not. Perhaps a short in the distrobution block?

I should also mention, that no matter what the circumstances are, I can never get the high or low side to come on by itself (meaning without the use of the AC - IE: by natural temp)
I believe that the high and low speed can work independently of each other through the use of the AC (IE: not controlled by temp sensor or thermostat ?) and not only by the temp of the motor. But it should work for both.

I did switch the high speed relay from the fan, with the horn relay (since they are the same). The horn works fine, and the blower works fine as well. I could not get it to hit or miss like it did before the swap, but that's common (because it does not misbehave all the time). But I assumed it was exhibiting the same behavior. Perhaps I should try that again to see if I can get it to fail? Ya know, just to cover the base.

So at this point, it seems the thermostat or temp sensor is not kicking on the fan naturally. But why? I assume the fan should come on at some point with just engine temp ? I feel I have an electrical problem of sort and that is not happenening. I thought maybe a bad connection to the fan, but then why would the fan work when the ac is on (sometimes anyways), but not by the temp of the car ?

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