Let me start by saying I'm a first time volvo owner and I bought it knowing it had a couple issues. It cold starts fine but once it starts warming up while idling in park my rpms fluctuate. Usually dropping pretty close to the point of stalling if not actually doing so. If I Rev the engine while in park there's usually an initial hesitation or stutter before kicking in. I also hear a loud whoosh sound when letting off gas pedal. While driving at low rpm and with a light load it doesn't do too bad except for coming to a quick stop will occasionally stall it out. During acceleration the engine stalls or hesitates very hard at around 2500-3500rpm. Its fuel consumption is also ridiculously high. It's throwing 12 ODB2 codes

what I know:
1. It was very poorly maintained
2. Seal in the exhaust cam gear is bad(inside of the timing cover has oil everywhere and there's some on top of the valve cover as well)
3.it's got 215k miles on it.
4. It's got positive crankcase pressure(did the latex gloves test)

what I've done so far:
1. Replaced cam sensor
2. Replaced crank sensor
3. New maf sensor
4. Replaced TPS
5. new plugs, ignition coils and wires
6. Replaced turbo boost solenoid
7. Replaced all the vacuum lines going into throttle body
8. Replaced IAC

 

Replace the PCV hoses and oil trap first (FCP sells a whole kit). Then do the seals and VVT (optional if you are not getting P0015 code). Consider doing the belt while you are in there. Idle issues could be the FPR or the idle control valve which I think you already replaced.

 

yeah I replaced the idle air control. and actually forgot to mention I also did the FPR and fuel filter

 

does your temp sensor wander when warm? You may want to test the resistance of your engine coolant temp sensor (located under the thermostat housing). The ECT can contribut to warm start problems.

 

^^^^^^^ ooooh, that's a good one. The ECT could be messing with your rpm's at idle for sure!

 

Temp Guage seems to be fine is there a way I can upload a video of its symptoms?

 

you can share a URL from YouTube / Vimeo etc. But... listening to the engine won't really be as helpful as listing the OBD codes. What I'd do is clear all the codes then drive it and see what resets. Temp Gauge wandering doesn't always happen with a bad ECT - testing the cold/warm resistance is the proper test. The oil leak really suggests your VVT needs attention - check out some of the Hudini posts on the topic. Seals tend to weep not spray oil all over but its possible the crankcase pressure really pushed them out. Did you check the rear cam seals as well?

 

Definitely replace the o-ring on the VVT gear on the exhaust cam. This is your number 1 threat. Mine eventually soaked the timing belt enough to cause it to slip and bend the exhaust valves. Fix this now. It's leaking from the little plunger thing on the gear itself.






Then clean or replace the PCV system. Mine was full of a nasty oily/water gunk that had several passages clogged up. You will probably have to remove the intake manifold to get to it properly. Clear the oil return holes to the crankcase. This is where mine had clogged the worst. You will probably need some hard plastic tubing to replace the original stuff on the PCV system. It gets brittle and cracks over the years.

It's the black plastic piece under the intake manifold. This is the oil/water separator. Sometimes they don't separate so well.


Now this car is super quiet. To hear a whoosh when letting off the gas plus the erratic idle tells me you have something off in the intake tract. Check this S shaped hose by the IAC motor. This one tends to crack in half.

 

alright so I got finished replacing the oil trap and all hoses about 20 min ago as well as a new intake manifold gasket. I also cleaned the ports going to the trap as well as I could. They were definitely clogged especially the bottom one. The s shaped hose you talked about got replaced as well. It was in fact broken. I'm going to reset the codes in a minute and take it for a drive but it's not looking too hopeful. I started it right after finishing and it still is showing all the same symptoms. I'll update again in a bit. Oh and the whooshing sounds like it's coming from the turbo when I let off the gas... don't know what that would mean but it is pretty darn loud

 

you can't really hear it as much as Id like but listen at the end right as I let off the gas.

also here's the codes it's throwing. It's been these same 12 codes since the beginning. The ones with * next to them means it was listed twice

*P0341, *P0107, P0237, *P0017, P0336, *P0172, P0202, P0237,

 

The happy meal of codes is really puzzling. You have codes for the cam sensor, crank sensor, cylinder 2's injector, the MAP sensor, and a boost sensor which as you noted some of those parts were replaced to no impact. Makes me really wonder if its wiring related - perhaps a grounding point or a short or corrosion on a connector. I haven't looked at a wiring diagram to sort things out but I'd consider removing the ECU and cleaning its contacts then reinstalling. I'd also look at the wires around the cylinder head - ie wires going to the coils, the connectors to the various sensors etc. Got yourself a real puzzle right now. :-(

 

That's why I posted on here lol. A lot of my info on how to test things and stuff to look out for has come from this forum.
It was mentioned earlier about timing belt because of the belt being saturated with oil... can these engines still run if the timing is off tiny bit? And I still have the feeling there's something turbo related going on as well. But I'll check the wiring in depth tomorrow maybe clean the ecu too

 

Yes it can run being off a tooth or so. With the codes you are getting and the unknown history, I would verify everything.

You shouldn't be getting any whooshing sound at anytime so I'd be checking the intake ducting from turbo to throttle body for any splits in the rubber. Here is a diagram: