1990 valve guide seals in a 1986

[ster1]

Hi folks,
I have an '86 466 that's been recently inframed (last year) and runs great. Smokes a bit if I idle it too long, though. No oil getting past the turbo, and into the intakes. Oil definitely getting burned. Compressions all between 300 and 320. So, I'm thinking valve guide seals. Here's the problem. International doesn't show valve guide seals for pre-1990 466 engines. They show a top - hat style seal for 1990 and later. No seal at all for 1989 and previous. Here's the question: what if I put 1990's seals in a 1986? Anyone ever done that?

[ster1]

Well, I can tell you they don’t fit so well. Either the valve guide itself or the boss the guide is a wee bit too long. Even with the spring plate in place, the seal is slightly distorted from being pushed up by the guide. Either shave the guide down or add another washer under the seal to make it fit. Exploring options. But I came across something worse yesterday. As I was screwing around with the valves, I found water in #3. Of course I was in denial initially, thinking it’s just from a stuck injector and this stuff is the only diesel that smells like water, and is pink. Ugh. Fortunately McCandless had some injector sleeves. I grabbed a few. I had never done a sleeve before, so I thought I’d need at least 1 or 2 to screw up before I figured it out. That was a smart thing to do. Anyway, got back to the shop,, made an extractor out of an old metric tap and some 3/8 rod. I used a jumbo socket as the hammer and made a hammer puller that got the sleeve out. I then took a huge socket head cap screw and turned down the big end to match (as closely as possible) the sleeve. The first sleeve was sacrificed to my learning curve, and had to come out. The second one went in straight. I put loctite on the sleeve last night, and drive it in, and went home. I’m about to go find out if I have a fix or if I need a new cylinder head.

[cadillackid]

good work on the injector cup.. common issue.. is it possible your "smoke" was actually coolant working into the cylinder at idle and steaming out the exhaust?

[ster1]

Originally Posted by cadillackid

good work on the injector cup.. common issue.. is it possible your "smoke" was actually coolant working into the cylinder at idle and steaming out the exhaust?

Thanks! I had heard of this alot back in my 7.3 days, just never done it myself. I just put the injector in this morning. I was concerned that if I had too much loctite on there, some would ooze out and stick the injector in there too, so I left it out until this morning. So, it's drained of coolant (it was time to do that anyway), and filled with water for testing. It's been holding pressure for about 30 minutes now, and that cylinder is still dry. When I pressurized it yesterday, you could hear the drips going into the cylinder, it was going in so fast. Odd thing, I didn't see a problem with the old sleeve. No cracks, gouges, etc. So.... hmm. Anyway, it seems to be on the mend. My smoke could be coolant, but I check my fluids every morning, and the coolant never went down, but the oil slowly does. I just did the inframe on that about a year and a half ago, and it started smoking and losing oil about 6 months ago. If the engine never had any valve stem seals, and I have valve stem / guide wear, that could certainly explain the smoke. Maybe this winter, I'll pull the head and send it off to be done properly. I haven't seen an engine with no valve stem seals since I was an airplane mechanic some 25 years ago

[ster1]

Update: I've been running it for a few days with the 1990 valve guide seals that don't really fit, and it's doing well. I used to get a good bit of smoke on start - up, and even when it was fully hot, letting it idle for awhile. All that is gone. All good now. Thanks for all the tips!

[Booyah45828]

The 466 originally didn't have them, then they used rubber umbrella seals to deflect the oil, and then switched to positive seals made from viton I believe. Your correct though in that the old ones didn't have seals. Diesel engines, inline 6 engines especially, really don't need guide seals because the ports are never under a vacuum to draw oil. Certain v8 diesel engines need seals because the oil won't drain back from the head quickly, which allows the oil to sit on the valve guides and drain into the ports. But, so long as the stem-guide clearance is correct, it shouldn't noticeably smoke.

IMO, the only reason modern diesels run positive seals is for emissions.

If you haven't driven this bus hard in a while, and it's got a lot of idle time, I'd suggest taking it out for a drive. Engines with a lot of recent idle time will smoke because the oil isn't being burned off like it normally would, and stacks up.