1999 V70R possible burnt valve?

[osman]

Usually in a turbo the cause of burned valves is using less than premium fuel.

[HWG09]

Been working on this a bit more. I cleared the codes yesterday and then drove around the block today and vibration was still there. Code popped up so I pulled it back in and swapped the #1 cylinder plug and coil with #2 where the code is coming from. I didn't put the engine cover back on but I took the car out for another spin and it was noticeably better. There was still some engine shaking but no codes and the acceleration felt better. I pull back in and put the engine cover back on to go out for a bit of a longer drive and sure enough the engine shakes more and codes flash again. I'm getting P0302 which is obv the misfiring cylinder and P1655 which I have no idea what it is.

I haven't checked the compression yet but I'm about to. Do I need to pull all the plugs when checking the compression or can I just test #2 and leave the others in?

[HWG09]

Ok this is weird. Just took another drive with the engine cover off. P1655 went away immediately (I think some of the engine cover screws were catching some of the spark plug wires).

Engine shaking is still there although acceleration is just ok but No Codes! Only with the engine cover off. What the hell is that about?

[HWG09]

Alright compression test results are 0 psi for cylinder #2. Bummer.

Only cause I can think of is I got an oil change in late Sep at a dealer (non-Volvo) with a groupon and they only put 5 quarts of oil in the car. A couple weeks later the engine is making this awful tapping sound and I go to Advanced Auto and my dipstick is bare and I have to put 3 quarts of oil in. The sound goes away and I'm good and now this so I'm calling the dealership who did the service to let them they will be addressing this issue (although I gotta wait till Monday to talk to the service director).

Will update on what happens but I'm down a car for the moment. Any leads on replacement engines?

[Pauloil]

yeah I just got same result on cyl. 4 with the tester from oreilly's on my 99 v70xc with 170000. I always look at the oil one day after and one week after any oil change I do, or others do to my cars.

[HWG09]

yeah I just got same result on cyl. 4 with the tester from oreilly's on my 99 v70xc with 170000. I always look at the oil one day after and one week after any oil change I do, or others do to my cars.

I'm unfortunately @ only 110k miles.

What are you gonna do?

[rspi]

I have seen burnt valves in these white blocks with less than 65,000 miles on them.

If you need to, you can drive the car with the #2 fuel injector disconnected. Have not heard of anyone having problems with doing that. I would likely pull that coil plug as well but that probably doesn't matter.

I usually check oil shortly after a change and monthly after that. Heck, the owners manual advises people to check oil at every fill up like they use to do at the full service gas stations years ago.

Check your receipt to see if it shows how much oil they added when they changed it in September.

[rspi]

Did either of you guys ever run fuel injector cleaner in your cars on a regular basis?

[HWG09]

Receipt says that put in 5 quarts of conventional 5W-30.

It was about 3-4 weeks later that I noticed the engine noise and discovered the lack of oil.

I did use a fuel injector cleaner probably about a month ago.

[erikv11]

The oil mishap is unfortunate but how could that lead to a burnt valve? I think you may be barking up the wrong tree there.

The valve stem seals are still 15 years old, regardless of mileage, that's a decent bet. Or like rspi suggested, maybe this is one of those rare cases where the #2 injector was clogged so that cylinder was running lean.

Regardless, it's a bummer my condolences, time for a new head or new engine or move on ...