Opinions wanted regarding valve job on 1997 850 NA

thedancingfiddle · Post by **thedancingfiddle** » 23 Jul 2020, 12:26

Hi all,

I have a 1997 850 NA, 276k miles. Has had a burnt valve and was running on 4 cylinders since last fall. So, finally got a chance and someone to help me work on it, and we got the head off.

My big question is, what all would you get replaced as far as the valves? One of exhaust valves on #3 has a big chip out of it, which explains the problem.

The car has gone through oil the entire 6 years I've had it, and so I'm wondering if this valve was just the first, and it won't be long before another one goes, in which case I'm thinking should I replace all 10 exhaust valves?

I'm definitely going to be replacing all the valve stem seals.

Thanks for all advice!

Post by **erikv11** » 23 Jul 2020, 13:33

On the valve stem seals, Volvo brand only, viewtopic.php?t=71962. 99% chance that explains the oil consumption but it would have been useful to know compression numbers before you pulled the head.

Replace the one bad valve.

Clean up the rest of the valves, no need to replace them.

Other then refreshing the seals as you reassemble, that should do it.

thedancingfiddle · Post by **thedancingfiddle** » 23 Jul 2020, 13:44

Thanks. I do have the compression numbers—it was a while ago that I did all the compression tests, but they were consistently around 190-200 except #3 which was like 60.

The other big issue now is that one of the head bolts broke off, and is stuck in the block. I'm calling around but have yet to find a machine shop or person who is up for the task of drilling it out and probably re-tapping the block.

bronco · Post by **bronco** » 23 Jul 2020, 15:13

thedancingfiddle wrote: ↑23 Jul 2020, 13:44 Thanks. I do have the compression numbers—it was a while ago that I did all the compression tests, but they were consistently around 190-200 except #3 which was like 60.

The other big issue now is that one of the head bolts broke off, and is stuck in the block. I'm calling around but have yet to find a machine shop or person who is up for the task of drilling it out and probably re-tapping the block.

get an engine from a junkyard . Machine shops are charging $150 an hour here and it always takes more hours than you think

Post by **FLXC90** » 23 Jul 2020, 15:17

How bout a picture of the broken bolt, may be more doable than you are thinking

bronco · Post by **bronco** » 23 Jul 2020, 15:38

FLXC90 wrote: ↑23 Jul 2020, 15:17 How bout a picture of the broken bolt, may be more doable than you are thinking

true , if it is sticking up and there is thread you can put a nut on and weld it then give that a shot , if its flush or below flush then I guess try it yourself . If you tow the car to a shop and they do it in car then that might be cheaper than another engine , if you have to pull it then don't bother is my wag. Pull it and drop in a different one with a good head.

Headwork aint cheap either. I spent 1000$ redoing factory "desirable" 289 ford heads in 1997

shop rates have doubled since then and the quote was for $500 initially.

The valves were bad and the seats had recessed and unleaded seats , new valves new springs yada yada . I still have those heads on a shelf

thedancingfiddle · Post by **thedancingfiddle** » 23 Jul 2020, 16:45

It's sticking about 1.5cm above the block. I'd be slightly worried that any kind of turning with a welded nut or vice grips might cause it to break again further down. But maybe if it's heated?

It did come up a wee bit before breaking, maybe 3 turns or so, with a lot of effort.

: headbolt.jpg (154.11 KiB) Viewed 1217 times

thedancingfiddle · Post by **thedancingfiddle** » 23 Jul 2020, 16:46

And the bolt in that hole directly behind it came out a bit hard, so we stuck a good one in there as a reminder to check the threads carefully in that hole.

bronco · Post by **bronco** » 23 Jul 2020, 18:08

you are in vermont? can't you just pluck volvo parts from a tree ?

Soak the heck out of that bolt for days weld a nut on it really weld it , get the nut cherry red with your welder then give the heat time to soak down into the bolt recite a few prayers and go for it

Post by **abscate** » 24 Jul 2020, 04:30

I’ve always wondered about this. A valve burns , and we replace one out of 10 ( its always an exhaust of course)

Cost drivers Of course

NA valves are as low as $10 from Oscar, each

Turbo valves are $100 for Sodium filled from Volvo, each.

There are lots of Volvos in Vermont. I had forgotten how beautiful the Green Mountain State is...