Probable burnt valve what to look at next.

Post by **rguzz** » 11 Dec 2016, 08:59

Cold compression on 96 850t is 170, 170, 0, 170, 170. Car has been using oil in a pattern consistent with bad valve guide seals, as a good guess: smoke on cold start, clears, returns after several minutes at idle, not clearly present under acceleration. Engine might have 220k miles, car is in great shape otherwise. I'd like to do a valve job and leave the block alone if possible, how can I best determine this idea is best? Visual of cylinder walls, etc? What do I look for? Should I consider rings and a look at the crankshaft? Not inclined to gamble on a used motor and would like do this only once ever again. So, specific question is how can I maximize the likelihood that I will be doing this only once and what should I do to be confident the block will support a fresh valve job?

Post by **Ozark Lee** » 11 Dec 2016, 09:09

A visual on the cylinder walls will tell you pretty much what you need to know. On the Volvos I have had the head off of I can still see the cross hatching on the cylinder walls at over 200k. What you can't have is vertical scars, those are indicative of bigger problems.

The bottom end on the white blocks is pretty stout, if it wasn't knocking then it should be fine. From your description of the issue my bet, without actually seeing it, is that reworking the head will get the car back to near new performance.

...Lee

Post by **erikv11** » 11 Dec 2016, 12:48

rguzz wrote:... So, specific question is how can I maximize the likelihood that I will be doing this only once and what should I do to be confident the block will support a fresh valve job?

- Use only Volvo branded valve stem seals. You can get a set of them for about 80 bucks from the dealer, search here at MVS.
- I usually spend up for the head gasket too. Definitely for the spark plug tube seals. Unless you can be certain about a cheaper head gasket recommendation from someone who has done several p80 heads over time (e.g., JDS60R, jimmy57); one person's experience with one or two jobs doesn't do it for me in this case.
- The biggest hurdle to doing this job well is cleaning the block surface well. Get a quality gasket remover or varnish remover, the Permatex product is of almost no value in my experience. The shop will clean the head surfaces of course. If at all possible send them the cam cover too, that helps a ton.
- Be sure to get now head bolts. All Corteco cam seals unless they were recently done.
- Taking the engine apart is easy, anyone can do it by following instructions, putting them back together close to factory is not you have to pay attention to detail.

101 · Post by **101** » 11 Dec 2016, 16:42

^^ I agree with Ozark Lee and erikv11.

If your engine is otherwise in known good condition (had regular oil changes, never overheated, etc.), all you should need is your head reworked and you should be good to go. The bottom end should be fine.

As said, use only OEM valve stem seals. You might be able to source a used valve or two as needed since the new ones are pretty pricey. I went OEM on the rebuild parts except the cam seals (Corteco).

Welcome to the burnt valve club. There's many of us on here.

Post by **rguzz** » 11 Dec 2016, 17:23

This car has been in the family for 15 years or so, purchased from local dealership from new. Driven by the elderly (really!) for the most part. Never over heated but has been low on oil on occasion, for sure. No unusual engine noise. I've been meticulous about caring for it over the last few years and it is up to snuff except for this issue, and long time history of excessive oil use as I noted above. BTW, what do I need to do about the lifters, anything? Thanks for all advise.

Post by **erikv11** » 11 Dec 2016, 17:27

When you pull the lifters, place them in order in some container where they can be immersed in oil then put back into the same place they came out of.

The Tracey's True Soap head gasket tutorial is the gold standard, you might want to give it a read.

PeteB · Post by **PeteB** » 11 Dec 2016, 17:34

Have you considered the big picture concerning timing belt, PCV, axle shafts, struts,
vac lines, brakes, is the rear main seal good, etc?
Our car leaks a lot but doesn't seem to burn oil.

Post by **rspi** » 11 Dec 2016, 17:41

With those compression numbers, I would not worry about the bottom end. Do get Volvo valve stem seals, others may leave you in the same or worse situation in 12 months (ask me how I know).