Normally on a cold start my rpms go up for a minute or so and then come back to normal. This has stopped occuring. It's very random, now when I start my car on a cold start my rpms do not go up anymore most of the time. Once in a while they will go up. Even if I leave my car sit for two days in 30 degree weather the rpms do not go up. Could this be the ECT? The temp gauge seems fine always goes up to midlevel. Taking the car in next week, just curious if anyone has an idea. I had it to the dealer 3 times already and they haven't been able to figure it out. Also my check engine light came on and my heater is not blowing hot air anymore. I had these three things at the dealer, had heater core replace, hoses, etc, flush, and dealer can not find issue. I was thinking for the heater issue maybe wasn't bled correctly.

 

anyone have the same issue with the rpms?

 

Mine's been intermittently ignoring its cold start sequence, but I have no problems with my heater, so either you have something additional wrong beyond whatever's causing mine to behave that way, or something completely different. Either way, I'll be interested to hear what the resolution of your situation is. (I suspect I have a coolant temp sensor that's going funky, but I'm not sure - one of these days, I really need to invest in a VAG-com so I can read the codes.)

 

Thanks yeah I think I have a couple things going on. I was thinking also it's the ECT. I'll report back after I take it in. Whatever is going on I think it's causing the engine light to go on. Audi dealer couldn't figure it out, they replaced some hoses etc...

 

ok here goes: the shop replaced the ect and the thermostat. They still have the car so I couldn't confirm yet it if it fixed the rpm problems, they used vag to scan for the codes. As far as the heat not being hot we are still at a loss. This has been going on for the past couple of years. Had the heater core replaced about 55,000 miles ago. Had a timing belt replacement done about 55,000 miles ago also which they did water pump at the same time. Also had thermostat done at same time. Had the radiator replaced 55,000 miles ago. Had the coolant system backflushed several times already. Audi has been trying to figure out for past couple of years. Now I have my car at an independent shop and they are recommending water pump( I might just do my timing belt change early since getting to the water pump is a ton of money in labor) and they want to possibly do the radiator. They also mentioned the hoses for the radiator. They backflushed the system and noticed that there is a discolored film like substance and thats the same exact thing Audi noticed but the backflush didn't solve the issue. I'm at a complete loss here along with everyone else why the heat isn't warm. From what both places are telling me it's a circulation issue but not sure where the problem is. My heat seemed to stop working after I had a coolant leak and the delaer had to replace the coolant flange and they also had to replace the ect and crankcase breather tubes, after that heat was not hot. Please does anyone have any ideas what could be causing this? By the way my a4 1.8t has 280,000 miles on it, bought it brand new and it's been my buddy every since! Even more amazing is it's a cvt, original cvt lasted 255,000 miles. Thanks for any help.