Is it possible for my car to have a problem and NOT pop a code??? For example, I just got my car back from the dealership today because my car within the last 2 months has not been achieving normal operating temp; every once in a blue moon it will. During this low-temp scenario my idle has been running real high (1200rpm) as if the car is still in cold start-up mode. Now, with all this being said my car is NOT popping a code! The dealer scanned it and they say "...duhhh there's nothing wrong with it otherwise the car WILL pop a code." Then when I re-iterate the symptoms to them they say "yeah, something isn't right." They won't fix it because they say that if they start to just install parts it might not fix the problem. What can this be? Can it be that something in my computer is NOT allowing any codes to pop even if there are malfunctions going on? I'm concerned... please help!

 

My friends car had similar symptoms.. since he lives in the cold, his thermostat was stuck open, so the coolant never warms up. This is a mechanical device so i doubt this will pop a code. Just a thought.

 

Benzo...your absolutly right! After the dealership yesterday I decided to bring my car to my local shop that I always use for general repairs. I told them the symptoms and they said it's most likely my thermostat. I told them to change it...I took a chance. It was the thermostat after all! The shop showed me the old thermostat and the seal was shot inside allowing the coolant to flow right through it! The car runs great now, my temp reaches normal and my idle is now normal as well! I am very happy...Maybe I should call up the dealership and tell them to take lessons from my local shop! LOL! Thanks for the input BTW. Oh, one other thing...the dealer said that a code WILL DEFINITELY POP if the thermostat was malfunctioning because there are sensors on coolant temp/regulation; I guess they were wrong!

 

Glad u got it solved. Unless the sensor malfunctioned itself, I doubt the code will appear no matter how long it takes ur car to warm up.

 

Told you it was the thermostat :P