Hello all! My wife’s 2012 VW golf has lately been stalling out randomly. It started 6 months ago, and then again 3 months ago, and now it’s happened 3 times within the past week. The electronics appear to still be functional when it stalls, but stepping on the gas does nothing and the car slowly comes to a halt, since so far it’s been happening only when going 30mph or less. We put it in park, turn it off and right back on again and it seems fine. AAA replaced the battery 6 months ago and we had them check it again yesterday and they said the battery is fine. Does anybody have any thoughts?
One of the first things suspected for random stalling is a faulty Crankshaft Position sensor.
One of the many things this sensor does is informs the computer whether or not the engine is rotating.
If the computer loses the signal from this sensor, it see’s no reason to operate the ignition/fuel systems and the engine stalls.
And no. A faulty crankshaft position sensor doesn’t always turn on the Check Engine light.
Concur, CKP sensor should be considered a suspect. Those can have a failure mode where they stop working when hot, but work ok once the engine cools down. Another idea, the fuel pump relay could be faulty. When this happens, does it seem to spit and sputter a bit more than usual on the re-start? If so, that would be consistent with a fuel delivery problem like the fuel pump relay. For an engine to just conk out like that it pretty much has to be from among
- no spark (e.g. CKP sensor, ignition module, … )
- no fuel (e.g. faulty fuel pump relay, faulty fuel pump, … )
- faulty electrical system, wire in the process of breaking, cracked fuse, …
the first thing I’d do if I had that problem and there wasn’t anything visually obvious staring at me from the engine compartment, like the battery was on the verge of falling off it’s holder, the first thing I’d do is check the computer memory for any pending diagnostic codes.
Edit: I should mention I have some experience, I owned an older VW Rabbit and it would stall like that, for no reason, even when driving down the freeway. It turned out to be the fuel pump relay and burned wiring where it plugged into the relay plate.