Hi there,

I am hoping someone here may have had a similar experience and could shed some light on this issue. I just got a 2006 Volvo S80 (2.5T, like all of them were).

When test driving, I noticed it surging while idling, the RPMs were jumping up and down and it was revving up and down. Each time this happened it would shudder, sometimes rather violently. I ran a code check and it said I needed new variable valve timing solenoids. Well, they've been replaced and it's having the same issue.

While trying to drive it today, it also popped up a warning saying "No Oil Pressure, Stop Safely". The oil does not leak; it is at a good level and is clean.

I'm at a loss, I thought that replacing the VVT solenoids would do the trick, the ones replaced looked relatively new, so it seems the previous owner was battling this issue too. Any ideas?

Thanks in advance!

 

The VVT are activated with oil pressure. Low oil pressure can cause VVT codes. (sorry you bought stuff you did not need, and please don't replace parts by code in the future - you have found out it can be very frustrating - find out what the real problem is first)

"No oil pressure" - that is commonly caused by a clogged oil pickup tube - if you remove the oil pan you might find it clogged with a granulated charcoal like substance. That stuff is formed - if you change the oil as Volvo suggests - (7500 miles)

Solution (if pan is clogged) is a clean pan and a new style oil pickup tube (don't try to clean the old one - you will be wasting your time and end up pulling the pan twice)

It's possible the turbo bearings are damaged, or the engine bearings (rod) are very worn also. You might want to check (and possibly replace) the rod bearings when you have the pan off. (the rod bolts are one time use)

In the future, oil changes every 5000 miles would be recommended - and Volvo changed to synthetic oil a few years later. So IMHO switch to pure synthetic oil with 5-7500 change intervals - and hope the turbo was not damaged.

Don't have enough info to talk about your fluctuating idle - but I trust your low oil pressure warning is not only appearing when the idle drops too low (oil pressure is directly related to engine speed)