Hi there all.

I recently posted another thread expressing some issues with my 06 S80. Previous suggestions have been to clean oil pan and pickup tube for sludge. This has been done, and the problem is still present. I am thinking it is either a vacuum hose leak or MAF sensor, but it could be something else entirely. Here are the specifics:

• Idle is rough after reaching operating temperature (10-15 mins of driving)
• Engine will also begin to surge at idle
• Car stalls sometimes after reaching operating temperature (starts fine, then shudders and stalls)
• Car sometimes presents an urgent message (which flickers on and off) stating, "No Oil Pressure. Stop Safely". This message corresponds with the car beginning to display rough and unstable idle symptoms
• Check engine code for PCV solenoids (both have been replaced, code came back on)
• Engine is not overheating

Can anyone with experience with these issues suggest what this might be? I would rather fix the issue myself than overpay the mechanic, as they've had the car for two months and have still not fixed the issue.

 

a few thoughts - test the engine coolant temp sensor. Google for resistance charts for cold and hot resistance. Vacuum leaks - spray around intake tubing, injectors, intake gaskets etc with some carb cleaner to see if your idle gets a bump. For the more hidden vacuum lines, a smoke test may be in order, particularly if you are seeing codes for things like an evap leak. Did you check the PCV oil separator? That can become the source of an intake air leak when it fails plus it can dirty up the MAF

As to the oil pressure - that could be due to a low idle rpm, low system voltage or an oil pump/pick up tube that needs servicing (ie dropping the pan would be required). You may be able to use a fully featured OBD2 or find a shop with VIDA to pull some run time data to see when the oil pressure is too low.

 

Thanks mt... good info. Your comment about the separator got me thinking about the pcv breather system. Could it potentially be that the breather system is clogged? And could that have an effect on the oil pressure? Although I'd think a clogged breather system would increase pressure in the crankcase, I wouldn't expect oil pressure to go down or be nonexistent.

In terms of the pickup tube, the pan has been dropped and they installed new seals and cleaned all the buildup out of the tube and pan. Oil pump hasn't been checked, though.

Probably needs a new MAF on top of whatever else is happening, I haven't owned a single Volvo yet that didn't need it replaced around this mileage.

 

Update: went to look at the car, and it now refuses to run at all. Previously it would reach operating temps before dying. Now it turns over, shakes, and stalls out. Revving it keeps it running a bit longer, but as soon as RPMs drop to idle it stalls out.