2001 PT Cruiser Overheating After Numerous Repairs To System

[Mycierra]

New to this forum as member but have read off and on many times. Have read many of the post regarding over heating but nothing particular to my problem. Vehicle has 273,000 miles.

Have had over heating issues for about (4) years. First replaced the radiator. Helped for quite a while but the gauge needle always fluctuated up and down from 3:00 ever so slightly. Since then have replaced:
Fan Motor - Ran alright but still with needle waiver. Eventually started over heating again.
Radiator Flush & Compression Check - No change, no diagnostic advice. Now leaking & gurgling.
Cap, Over Flow Reservoir - No change
Water Pump - Ran fine for a few months and mechanic had to replace this past Feb. under warranty. Started sporadically over heating again beginning a month ago. No gurgling in the over flow reservoir though. Minor leak somewhere.
Relays replaced, which were the most recent (couple of weeks ago) and secured the air escape nozzle. Now not leaking but still over heating after 45 min on the road in upper 80 degree heat. Fan not going on. It seems this happens intermittently though. Direct power to the fan and it runs. Fan runs immediately after any repair but then later notice it's not coming on when at idle.
BTW... I'm a chick and not a mechanic. Some of the work is by mechanics, some by my boyfriend. Have a repair manual but still scratching our heads. Thoughts anyone???

[ptcruisersteve]

I would suggest you remove the low speed relay and start the engine. Your radiator fan should immediately come on. If it does not come on then you should check the wiring from the relays to the radiator fan. Check the radiator fan connector for bad contacts. If it does come on then I would check your coolant temperature sensor. Check the wiring from the sensor to the PCM. Make sure it making good contact on both ends. If your PCM does not get a reading from the coolant temperature sensor it will not turn on the radiator fan.

[lemonPT]

Curious what the outcome was?

[kshanok]

I had a stubborn overheating problem myself. My problem was rust and other sediment in my cooling system. I had a mechanic supposedly flush my system but it still ran hot. If you put a radiator in with the same crap I had then that would have plugged up also. Take out the thermostat and disconnect both radiator hoses from the radiator. Only do the next step with engine cold. Run a garden hose through one radiator hose and watch what comes out the other. If you get a lot of rust you will need to replace the radiator again. I also installed a 180 degree thermostat and my car runs cool as a cucumber. Don't forget to completely clean the overflow tank.

[Mycierra]

Boyfriend working on this today. Should have some results next week. At least, for now, am able to get back and forth to work (35 miles one way) due to rural route. Will report back when I know more.

[MJKnight]

Soooo its sorta fixed?

[chuzz]

Sometimes it's a simple thing like a loose hose clamp. They can suck air in and drive you bonkers. If the flush and thermostat suggestions don't work, just check and tighten ALL hose clamps. That includes the heater hoses. And make sure you're running a 50/50 mixture of anti-freeze and distilled water.

[Mycierra]

Follow-up/Update:
PTCruiserSteve......boyfriend followed your advice but did not find solution. However, it lead him to the PCM which when taken apart had oil in it. Can't be good so he played stump the mechanic at the local Chrysler dealership and they suggested the oil sending unit. (Can't believe it but sensor failures can result in fluids back flowing up the wires and into the PCM. Found reports of this elsewhere on the Net) Repaired (what a pain the #%$) but still no change either.
In desperation finally went to "Just Answer" where I connected with a retired Chrysler Master Technician who spent (3) hours working with me and my boyfriend over the phone. They went thru testing the relays and found, although they had been replaced already, that the lower relay had failed.....again. Because of repetitive failure he recommended replacing the fan/motor assembly. This had also been replaced a couple of years ago and worked fine when a hot wire was hooked up directly to it. Given these previous repairs we never earlier considered this the area of concern. However, we made the recommended repairs the very next day and, two weeks later, the car is running great. No further overheating issues. The tech said the repeated burn out of the relays was due to the fan/motor drawing too many amps and frying them. So, even though in theory it functioned, we replaced it anyway. Let's see where this is in six months.
Much thanks to those who offered advice. Hopefully my experience will help someone else struggling with pesky, mysterious over heating issues.

[Mycierra]

MJKnight........no, never fixed but because I drive a country route at a min. of 55 mph and have no traffic tie ups; I can keep air blowing over the motor. But boy, if I have to stop and idle (trains etc.) or drive too slow (construction) she starts to overheat. With morning temps cool, worked well. Hot afternoons; dicey on way home. Glad we finally resolved it.

[chuzz]

Glad to hear you got it fixed. Happy Moparing.