I did a radiator flush, refilled the radiator with water and cleaner, and drove for about 10 minutes. Because I was trying to get my car to temp so the fans and water-pump would kick in I was keeping and eye on the temp gauge. After a few minutes I noticed I was loosing power, but my temp gauge was not even going up half way. I made it home, with the temp still reading normal, but with the car obviously overheating. I added water, and found that the radiator plug had come out, so I was driving without coolant/water. So my question is how bad is the damage probably? Also why didn't I see the temp gauge rising? I notice that the thermostat housing is near the radiator cap. Is sufficient coolant required to transfer heat to the thermostat for it to work?

3 Answers 3


Ok, no real way to tell what damage was done. Possibilities, anywhere from scored pistons and cylinder walls. Blown head gasket, cracked head/block. I would fill the system and bleed out the air and see how it goes. Very strong possibility all will be ok. As for the temp sensor/gauge not reading correctly, if there is not enough coolant in the system it has nothing to read.

  • This type of event will have affected the longevity of the engine but, no way to even start to guess by how much... good answer, good advice.
    – Solar Mike
    Aug 19, 2017 at 16:50
  • Further reading on the internet suggests that the car may have gone into a "limp mode" when sensing the overheating. This could also explain the loss of power, but with the heat sensor not working, is this really a possibility?
    – Frank
    Aug 19, 2017 at 18:05

Just got my 2002 PT Cruiser LE DREAM. Driving home from the lot, I pulled over for a couple of minutes. Started running hot, temp gauge going up, so got back on the road. Got home, drove to store, every time I stopped, the overflow was bubbling over. It got quite hot, which really worried me that some damage had been done internally. Honey is retired mechanic (thank goodness), he tried to turn fan manually with engine off... it would not turn. Luckily the dealer had a brand new fan, got that and changed them out (quite the job in labor). Still fan would not run, on A/C, on heater, nothing... temp climbing. He used a 12 volt test light to the low fan relay junction, got no juice. Bought $8 Low Fan Speed Relay (there are two, low and high speed, he tried replacing low speed first because that is for fan... high is fan condenser relay, but there was nothing wrong with that once we got the first fan relay in), installed that... VOILA! My new beautiful PT Cruiser running like new. Also, someone had not tightened down a bolt on the manifold cover, causing it to suck air, which caused a rough idle. He made sure everything was tight and now I can drive my zippy cruiser with confidence!! No internal damage... Good luck to you on getting yours running right... it is well worth the time!!! : )


If the coolant temperature sensor isn't in the coolant, i.e. in air instead, it won't register the water temperature elsewhere in the system.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .