plan for in-car valve stem seals replacement

whoa · Post by **whoa** » 18 Mar 2010, 12:36

I'm going to do an in-car valve stem seal replacement on my '96 850 Turbo wagon, and since I got so much good info from the write-ups here and on other Volvo forums, and since I haven't found one specifically about this job, I hope to contribute one. I thought I'd try using Google Sites to host it. Right now I've just created the site and, to play with it, put up info about my plan, parts, tools, etc.:

>>> In-car valve stem seals replacement tutorial <<<

Any advice gratefully appreciated...

Post by **jblackburn** » 18 Mar 2010, 13:51

Cool, good luck with both the car and the site!

I'd offer help if I could, but I haven't done anything other than Dreamweaver and a whole web page in basic HTML for a class a couple years ago.

The only valve seals I've ever replaced were on a strange 12-valve (yes, 3 per cylinder) Accord, but it was a pretty easy process. I buy cars with weird engines apparently. You should be able to find tutorials for other cars and follow more or less the same procedure, and I know there are pictures of a head replacement lurking in a pretty busy topic on the forum here if you need pictures of what it looks like when the head's apart. You learn more about something as you dive into it headfirst anyway

rjaywhit · Post by **rjaywhit** » 18 Mar 2010, 13:59

The only help that I can give is that I have seen where someone fashioned a fitting for an air compressor hose that fit into the spark plug threads. They used air pressure to keep the valves from dropping into the cylinder when the spring was removed from the valve stem to allow the replacement of the stem seal.

Post by **JDS60R** » 18 Mar 2010, 14:27

How did you diagnose the valve stem seals as a failure/leak vs the turbo seals?

whoa · Post by **whoa** » 18 Mar 2010, 14:44

jablackburn: Creating a Google Sites site is the web equivalent of changing a headlight bulb.

rjaywhit: No compressor, so I'll stick rope in the piston and squash it up against the valves.

JDS60R: Not entirely confident about the diagnosis, but I could not feel any play at all in the turbo shaft, and there's a big puff of blue smoke on revving the engine after a 10 minute warm idle. The car has not been driven hard... Good compression, good power, decent mileage. I'd love any ideas about diagnosis!

Post by **JDS60R** » 19 Mar 2010, 10:32

Give a call to www.ipdusa.com I think they will help you with the diagnosis. If i remember correctly the stem seals and guides having excessive wear make more smoke when you let it idle and the turbo seals will give you more smoke when you rev them. I believe the theory is that while reving the turbo it creates pressure and there would be no suction past the valve stem seals. Also - I usually see the valve guides in almost as bad shap as the seals so I am pulling the head. You can always inspect first. I am just getting a gut feeling from what you wrote that you may have a turbo oil seal issue. Have you checked the intercooler or OTE pipe for signs of oil?

whoa · Post by **whoa** » 19 Mar 2010, 12:12

Thanks. There was no play in the turbo shaft, so I am hoping that makes turbo issues less likely. I will see more as I dismantle things for the timing belt. A new or bigger oil leak has started in the last day or two; looks like it could be the rear main seal. So this all might end up being academic.

whoa · Post by **whoa** » 20 Mar 2010, 22:16

So here's what happened:

http://sites.google.com/site/incarvalve ... s/write-up

whoa · Post by **whoa** » 21 Mar 2010, 10:34

Do you think this write-up should be linked to in the repair database? I know I would have found it useful...

Post by **Zimbo** » 21 Mar 2010, 11:43

Terrific write-up!
Most of this stuff is beyond my mechanical aptitude but I enjoy reading and learning.

I wonder if you wouldn't mind answering a question: Replacing the camshafts, I had always thought there would be a little play with regards to the proper seating. Is that not the case, do they go back in place well seated so there's no big worry about lining them up? I guess that ties into your decision to not use some sort of cam lock. I had thought it was in part to make sure the camshafts remained in place, but I guess that's where my lack of understanding is.

Thanks for taking the time to document this as you went. I've contributed a few write-ups and know first hand it takes a decent amount of time during and after to accomplish the write-up task.