idle issues still.temp changes?

[drumrooster]

04 PT auto non turbo..been dealin with a rough idle for awhile now??.new plugs.wires...Cam sensor..IAC ..replaced thermostat awhe back.
for som.e reason its been running cooler than it ever did? Drivin at 55 with cool temps 30 down the temp guage runs about down from half way to the next mark.it seems to idle better when the temp is runnin at the half way mark? My question is...is there something temp related that would mess with my idle? New temp sensor in it too..

[ptcruisersteve]

We need more information and history on your PT Cruiser.

How many miles on your PT Cruiser?

Has your water pump been replaced yet?

How long ago was your thermostat replaced?

Any engine trouble codes?

[drumrooster]

160,000 yes new pump n belt at 120..termostat less than a year ago 2xs to be sure it wasnt it..from the dealer..bad pumps not gonna make it run cooler..thermo maybe sticking..? Just wonder if the cooler temps are causing some of the idle issues?..no vaccume leeks..code showin po440 /522

[ptcruisersteve]

I would recommend getting a noncontact infrared thermometer and see where there might be a temperature change at 2,000 rpm's. Check the temperature difference between the upper and lower radiator hose and other places like the thermostat where a restriction might occur. It seems to me when your PT Cruiser is running at high rpm's you are getting a restriction flow in the coolant system.

[ptcruisersteve]

Seems you might have a few different problems.

P0522 engine oil pressure or sensor voltage issue. This might indicate low oil pressure causing your idle problems. Have you tried making sure the wire going to the oil sensor is good and making good contact. Is there any oil leaking from the oil sensor?

If you have a OBDII Scan Tool have you already reset the engine trouble codes and this P0522 came back again?

[ptcruisersteve]

P0440 - A huge evaporative system leak or a failed NVLD unit.

Have you checked your gas cap? Sometimes the gas cap doesn't make good contact with the surface its touching so make sure the surface is not rough causing it to leak.

[drumrooster]

New gas cap reset codes n it came back...replaced oil sending unit awhile back no help..i will check it again for leeks? How would the oil pressure switch cause an idle issue??..gonna replace the filter at the tank evap next..maybe theres a big leek back there?

[ptcruisersteve]

If you have an oil light on that is an indication of low 4 to 5 psi oil pressure. Low oil pressure usually means the engine is not getting enough oil which can lead to trouble for the rod and main bearings, and upper valve train components causing rough idle. Any indication of low oil pressure should not be ignored and should be diagnosed immediately.

Another member had not checked the oil level and found it to be 2 quarts low and it was causing rough idle.

[drumrooster]

Never been low on oil..and oil lght never comes on..oil changed alot..just hoping its not low compression.....

[ptcruisersteve]

Originally Posted by drumrooster

160,000 yes new pump n belt at 120..termostat less than a year ago 2xs to be sure it wasnt it..from the dealer..bad pumps not gonna make it run cooler..thermo maybe sticking..? Just wonder if the cooler temps are causing some of the idle issues?..no vaccume leeks..code showin po440 /522

P0522 - Low oil level or motor mechanical fault

Faulty Oil Pressure sensor
Oil Pressure Sensor harness is open or shorted
Oil Pressure Sensor circuit poor electrical connection

If it was my PT Cruiser I would not drive it until I found out what was causing the engine trouble code P0522 to trigger.