2004 volvo s40 1.9t poor drivability slow acceleration excessive oil consumption/leaking oil pan.After doing some research I've found that the crankcase ventilation system could be to blame did the glove test on the oil filler hole and glove inflated also noticed slight amount oil blowing out of the filler hole along with oily turbo hose I scanned for codes and found p0128,p0015,p0442 wondering if these could be a clue? also a tutorial for changing out the crankcase ventilation system would be useful.Any information would be a help thanks

 

P0128 is saying the coolant temp is measuring too low. I'd spend the $75 and put in a new thermostat and ECT sensor. It would also be a good time to check the upper radiator hose as on the 1.9Ts they are prone to leaking at the tap to the overflow reservoir hose. P0015 is saying the VVT timing is retarded. That can be due to the VVT gear/solenoid not actuating properly. VVT is run by oil pressure so you should pop off the timing belt cover to see if its leaking onto the timing belt. The VVT can leak so worth checking out. P0442 is an evap system leak. First thing to check is the gas cap seal. Get a new seal, clean around the filler and see if the code returns. Other causes may be the Purge Valve or the vacuum line going all the way back to the cannister (which is ahead of the rear wheel).

So, it sounds to me like 1) you need to attend to the PCV system (starting with the oil separator) to correct the positive crank case pressure 2) clean off all the oil residue to see where the leak is coming from (pan gasket wouldn't be my first suspect - start by cleaning then look for the highest point you see new oil). I'd be looking at PCV hoses (like the one that goes up top near the filler port) and the VVT gear. The VVT sounds like the likely cause for your loss of power so you'd want to read up on symptoms and tests on how to repair.

 

thanks for reply seems like p0128 and p0015 codes are common on these models. Timing belt seems to be in good shape it was replaced at 95k by previous owner car now has 123k not sure if the owner before changed the oil regularly or not. I cleared my previous code p0045 by replacing gas cap seemed do the job ill check vacuum leaks next. Checked the oil filler cap appears to be built up sludge around it checked also checked pcv line going into the intake feels hard is this normal is there anyway I can check the pcv valve for proper function?

 

the standard test for the PCV system is to measure the crank case pressure which is the point of the glove test. The oil separator is what allows the intake to provide a vacuum so that's the first thing to check out.

https://www.ipdusa.com/blogs/512/vol...sues-explained

and

https://blog.fcpeuro.com/volvo-pcv-b...-and-diagnosis

 

Thanks for the links will check them out