2003 Audi A4 1.8t :
I have started to notice on days when it gets to close to freezing temperature when i start my car it does not go into the high idle how it usually does on a cold start. The rpms just start off at the regular speed (under 1k rpms). When this happens I noticed that it takes forever to heat up. Sometimes when I am in one place the heat will start blowing out cold. Today once again it took forever to warm up and i noticed the temp. gauge get to a bit before half way and then dropped a little. The only thing that comes to mind is a thermostat. Any ideas?

 

coolant temp sensor maybe?

 

Would that effect the idle at start up and also the heating not working at times?

 

It could. If it's sending the wrong temp to the ECU, the ECU will lean out the mixture and won't throw it into "cold start" mode.

 

Thanks

 

I have the same situation happening with my '05, is this something that could damage components eventually or is it just the inconvenience of slow heat?