Cylinder miss and overheating

[sick_willy]

Hello, I have an 01 PT with 133k miles on it and I'm just trying to get a better understanding of what could be wrong with it. Recently I received the P0303 code after some strong shuddering in the engine. A few days before the shuddering started the engine started to overheat while I was sitting idle for a long period of time with the car in drive. It still has the stock wires and I'm thinking that's possibly the reason for the miss. I'm not sure about the overheating though. Could it be a blown head gasket? It's at normal temp when I'm driving and when the car is in park idling. It only gets hot when I'm in drive idling and the shuddering begins. It also shudders worse when the AC is on. I'm not sure if this could be related or if that's a different issue. I plan on taking it in and seeing what they say as I really am not car savy. Worst case I'm feeling is the head gasket and best case is replacing the wires, and plugs while they're at it.... I think? I really haven't had any problems before this other than I got the front right tie-rod replaced a little while ago. Any input would be awesome! Thanks.

[CREWZIN]

Willy,

A few reason why the PT overheats. Blown head gasket as you already mentioned, bad thermostat, trapped air in the coolant system, water pump or anything to do with the radiator fan (relay, burnt out low or high speed fan motor or the ECM). Diagnostics have to be performed to find out what the exact problem is.

If you do a search on this forum for "overheating" you'll find dozens of threads that talk about the causes and cures.

No matter what it is you sound like your going to take it in to have it fixed. The dealer is the most expensive place to take it to so if you can find a trustworthy mechanic elsewhere, go there first.

With the kind of mileage you have, I have to ask if you've had the timing belt, water pump, serpentine & alternator belt changed? A sipping timing belt could also cause overheating problems along with, of course a bad water pump.

[Gretta]

I have a 2003 PT Cruiser...with just about 100k(s)...I took it to the mechanic when I could get any heat from the car...It would only blow warm for a split second and then get cold. He changed the thermostat and on the drive back to me, the car was squealing like a pig and it began to overheat...no problem overheating before that...he changed the new thermostat back to the old thermostat...placed water into the radiator and it began to overheat again...he then removed the thermostat and said it should not happen again..the next day we would began to tackle the problem again..(it was 8 pm in the evening)...he thought if he removed the thermostat..the car would not run hot...he tried several things the following day and he was not able to find the problem..so I have it at the dealer and he found that the young man should not have placed water into the radiator, but antifreeze only..does this solve my overheat problem or is there something else the mechanic should know?

[CREWZIN]

Only have to guess at your problem but if you read the answer above, there's a few reasons why a car overheats.

I've never heard of 100% antifreeze, it's almost always a 50/50 mixture. ON your no-heat problem, it cold have been that your cooling system was low and when it's low there's air goes to the highest point which is the heater core in the dash. The water won't circulate properly threw the core and you have no heat. When the mechanic changed the thermostat he might have bled the system properly leaving more air in the system and the cause for overheating.

Tell him to use a 50/50 mixture and also that Chrysler recommends HOAT coolant only. Also to make sure all the air is bled from the system.

http://www.search-autoparts.com/sear...27/article.pdf