I've got a 2000 V40, bought from a friend of mine this past summer, and it's got a number of general problems (it wasn't taken the greatest care of mechanically I've come to find out) that I'm working through slowly as the budget allows. Right now, briefly, I'm curious about the RPM dipping every once in a while but, often enough that I'm concerned.
Some context: I've had a few things worked on and replaced on it since buying and just recently had to replace the PNP switch as I got the flashing arrow signal and check engine. A little before this and now still, the RPM will dip down to 600, nearly 500. When it does this, I can hear/feel the engine chug a little bit as though it might die but, never does, it always recovers. The only consistency I've noticed is that it never happens when I'm moving/driving, only happens when the RPM are already around idling speed (~700-750). Sometimes it's while sitting at a sign/light/parking space, sometimes it's right when I come to a complete stop at a sign/light/parking space, sometimes it's when I put the shifter into Park - but, never one of these more often than the others.
Extra context: It was having a bad misfiring problem a couple months ago - this was one of the things that I had fixed recently (not sure exactly what all the mechanic did) - and has been resolved. It does have a significant oil leak, I think around the head gasket, which I'm trying to get done ASAP but, can only do it as budget allows. The catalytic converter was showing signs of having a couple weird issues when I had the misfire worked on but, mechanic said it should be fine for now (obviously no guarantees). I believe the fuel pressure regulator was also replaced or cleaned (?) which fixed a problem it had with not starting right away - it always started but, before replacing this, would take a second of rolling over to get it.
Overall, I'm not certain how concerned I should be (if at all) about this problem. Any suggestions, help, or advice would be greatly appreciated! Thanks!!
