Hello, i own Audi a3 2010 1.6 TDI 105HP 7 speed auto. I’ve begun to have trouble starting my car when engine gets to working temperature, let me explain.
When the car has been sitting overnight and is completely cooled, the engine starts perfectly. Than i go for a short drive and engine warms up. I park the car let it sit for a 15-30 min while i finish some things in city etc. And when i come back to start a car, it either throttles good 10 sec before starting or it starts/shuts down/starts again by itself. This happens ONLY when car is warm and is sitting for a time. If i turn it off and start it again immediately than it starts just fine.
One other thing i noticed this happens the most when my car is acting weird, by that i mean my car idle rev are around 900. Sometimes while i drive car will go into this weird state when i stop at traffic light, idle revs would be at 1000, and i feel the car drives different, like its more sensitive to gas. I attributed this to DPF regen because i don’t drive as hard, but my DPF has been checked and they said its under normal numbers. Any ideas?
Did you have the overheating problem fixed from your other thread? Also what country are you in because that may have been a dumped vehicle because someone did not want to fix the problems . You may be forced to find an Audi dealer and spend a lot of money.
Yes, it turned out that radiator was clogged inside from coolant sitting in car too long, it was replaced and temperature is fine since. I’m from Serbia, car was imported from Italy because it had faulty Robot that shifted gears, car dealer said he had it replaced and re sold car to me, and car really shifts good so i think its not that. Now i don’t know if car was sitting few years in Italy not being driven few years before being brought here, but that might be the case.
A diesel’s rpm and load depends on the fuel added. It has no throttle so it will take in the same amount of air every stroke. So the higher rpm likely means more fuel is getting in than is needed.
Sounds like it could be a fuel injector problem. It could be a temperature sensor problem, too. A good scan of the car with a pro-level tool when you try to do a hot-start would help pinpoint the problem. Find a VAG specialist, not necessarily a dealer, to diagnose the problem.
I was thinking leaking fuel injector as I read through the OP’s symptoms. That could explain the hot start problem and the unstable idle rpm. A problem developing with the injection pump should be considered too. Seems unlikely to be a problem w/the turbo, so that’s good news. An egr problem might cause both of these symptoms, but that would usually turn on the check engine light and store a diagnostic code. Rotational sensors (crankshaft/camshaft etc) can sometime fail when hot, so that’s another possibility. Those faults sometimes don’t turn on the check engine light or store a code.
diy’er, no experience w/you car or its configuration.