After changing my oil recently the oil pressure light came on and I would hear some clunking noises coming from the engine bay. As soon as the light comes on (takes a couple of seconds) I turn the car off and after starting again it doesn't come on and everything seems fine. One thing that also happens is the RPM drops immeditly to about 800 even after a cold start and I am used to it staying up there for a minute or two although I am not sure if that's related. The car is a 2015 B7 Passat with the 1.8L turbo engine. While changing my filter a couple months ago there is the piece that broke off the hub (second picture) but I am not sure if that is also related to the oil pressure light or not as the car has been running fine for a couple of months with it like that. Filter hub Broken piece from the hub

So what would cause the light to come on after doing the oil change?

  • A dry oil pump? – Pᴀᴜʟsᴛᴇʀ2 Nov 11 '18 at 19:51
  • Agreed, there was probably some air trapped somewhere in the oil system. Check the oil level and top up if necessary, now you have got rid of it. – alephzero Nov 11 '18 at 20:07
  • I wouldn't worry too much about the different RPM on cold starts, so long as the engine pulls OK from cold. It can be is very dependent on factors like air temperature, etc. The ECU might make the mixture richer for a cold start, or it might increase the idling RPM. Figuring out why it chooses one over the other can be a complete mystery. – alephzero Nov 11 '18 at 20:10
  • @alephzero This was not a single occurrence it happens somewhat occasionally every cold start. And the thing is the light comes off after it starts then comes on and I immediately thereafter shut off the engine – method Nov 11 '18 at 20:47
  • The first sentence of your question reads as if it happened only once. You did say "comes" not "came" in the second sentence, but a lot of people here don't write "precise" English grammar (and English might not be their native language), so I admit I didn't notice the word "comes" the first time I read the question. – alephzero Nov 12 '18 at 0:50

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