good work.

glad it is working out for you.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

You said the valves were shot but then you said there was a lot of carbon, perhaps preventing them from seating. Which was it? I'm curious as to why you didn't try to clean the valve seats and put new guides in. Seems like it would have been a lot cheaper.

Also, did you ever really try the Italian tune up. It is not unusual for it to take awhile to get carbon out from under the valve, but usually it gets blown out eventually.

And do you think this job was really worth it? First of all, someone here said the head was about $600. If that is the case, do you think it was worth it given you put in maybe 10 or 20 hours of labor?

If it would have been my car, I would have adjusted the valves and pushed it hard on the highway for several weeks. Then adjust the valves again. If it didn't start to run better by then, it would have been junk yard time.

240Joe

I think what you have proven is that valve guides can still be a signifigant contributor to oil consumption on a diesel 617 perhaps. Although I am not quite sure why it seemed to burn oil for the first 100 miles or so after the head rebuild and then decided to reduce consumption. Yet happy for you it stopped.
Something to do with the rings perhaps? Had to be something as it could not have been the head. Any thoughts out there? It was pretty obvious you needed a valve job earlier though.
Did the new oil also clean out the rings a little in that 100 miles? You were loaded with carbon it seems. Or perhaps heal up a slightly leaking turbo seal? There has to be some reasonable explanation of this event.
An old wives tale from years ago was when restoring compression with a valve job.The rings would not adjust to the increased load again and you would start to burn oil at an ever increasing rate. Yours seems to be the direct opposite situation somehow.

I beg to differ. I don't think this whole episode has proven a thing, which is typical of this religion of compression testing and the action taking after you get the results.

First of all, these engines don't normally burn valves. Whoever keeps saying that is flat out wrong. It sounds to me that all that was needed was to blow the debris out from under the valve that was not sealing. Once the compression came up on that cylinder, who knows what the oil consumption would go to.

And the idea of spending $600 and many hours to "fix" a possible non-problem is a huge problem in and of itself, not to mention if it's worth doing to a $1500 car.

What is needed is smart troubleshooting and better advice on these boards.

240Joe

I burned an exhaust valve once, due to an overpressure situation on a gasser. I drove the car for a few hundred miles and then removed the head. The guide for that valve was completely shot. Several hundred inch/1000 of play. Being blown around due to the imperfect seal (to say the least) apparently put pressure on the stem.

Well Joe we all seek smarter troubleshooting. There is a thread I just left about 300d compression and start problems. I am not one but perhaps you could go over and give him a hand. He really needs all the good ideals he can get.
In life I think I have had a loose piece of carbon under a valve seat myself and it has cleared. That carbon though got loose in the engine and temporarily stuck in there. With an engine that has badly carboned up to the extent of keeping valves off the seats there is not much chance of getting enough heat to burn it off with a low compression cylinder in my opinion. The actual day to day pounding on the seat is usually enough to keep it at bay. The only thing indicated to me here is to give your engine the occasional good highway run to prevent it happening to start with perhaps. The valves and seats also do generally wear with milage and his car had some sloppy guides as well. I still am curious why it continued to burn oil for the first 100 miles.

Not disagreeing with you here, But here's my tale of a 617....

Around 8 years ago, I bought a W123 300D with a 617. Great no probs...OR so I thought at the time. Within the first week, it developed a mis-fire on idle, a little mysterious as it would come and go, but got to the point it was perminent--It smoked on idle as well as light low revs load....

All the usual such as injectors, timing, full service, cam chain and valve-clearances were done to no avail....

As it happened I had a hole in the exhaust as well, Not a big hole, but enough....When starting from cold, you could hear the hissy wheezy noise at a regular interval corrisponding with 1 of the five cylinders, coming from the exhaust....

Head off time, and sure enough an exhaust-valve was leaking....

The cause was not Burning, or Carbon. The engine was a Very high mile motor, having done around 300K miles. The valves had recessed somewhat and a tiny ridge had formed on the valve-heads at the inner diameter of the sealing face. This tiny ridge had in portions broken off and embedded itself into the sealing-face of the valve, being forced in that direction by passing exhaust gasses causing it not to close completely...

A quick lathe job and re-cut of the valve-seats as well as new valve guide-seals effected a complete cure. the engine has since done 80 odd K with no issues, it doesnt even use any significant amounts of oil between changes The bores were very worn with a significant wear-ridge, easily felt with the finger-nail. The engine however still starts easily and does not smoke apart from the first few seconds of cold running....

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http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

i am really tired of you. you need to sit down and be quiet.

you are not helpful and you are not trying to be.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

t wal...

I don't care if you are tired of me.

And I am helpful. Doing a $1k head job on a vehicle worth $1.5k IS questionable. Doing a $1k head job on an engine that doesn't need it, is WRONG!

I'm glad you didn't comment on the technical issue. It's good that a man knows his limitations.

240Joe

Tom,

I've invented a new game, I have Joe on my ignore list so I can try to guess what kind of nonsense he/she/it is spreading just from the responses. It's much less aggravating than actually reading the posts, so everyone needs to stop quoting him/her/it, that ruins my game.

Thanks, Tom, you've been helpful.

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1998 E300D, 287k, barely broken in.

Hi Joe, wish you had chimed in when I was asking for advice. The head was diagnosed with "significant corrosion" (see my other thread about returning my core), so there was a little more going on here than just valves. But, I did have a good feeling that the valves weren't seating at all (see the beginnig post with the compression numbers) and I felt like taking a chance by bandaiding could cause me to actually do the job twice, which I would feel like wouldn't be worth it. But doing the job once, sure, I felt like it was worth it. I did try the Italian Tuneup--for most of the first six months I owned the car, I droved it like I stoled it, as they say. Minor improvement, but no real gains. I went with a reman from Metric because I spoke directly with a couple of guys who had "local" machine shops do a head rebuild and the cars actually ended up worse off and they did the job again. While I enjoy wrenching on my cars in spare time, ain't no way I was going to do this twice. Maybe a case of the "might as wells" but if you've got the head off, why not make sure it's done right? JMHO.

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1998 E300D, 287k, barely broken in.

I can say for sure that the guides in my head were causing significant oil consumption--a quart every 7 or 800 miles. I think I may not have been clear about my update. The car continued to "smoke" for about 100 miles--didn't see much consumption that I could guage as ordinary or not. The smoke could have been gunk in the exhaust or, even though I cleaned 'em up pretty good, could have been oil residue in the cylinders from when I did the compression check with the oil squirt (I never really ran the engine after that test). I'm hoping that my slight tailpipe smoke now is due to turbo seals, and I may tackle that next winter. The next time I do valves, I'm going to do another compression check for fun. I wonder, too, now that I think of it, if improving compression in the cylinders doesn't cause the scraper ring to expand properly. Anyway, I'm happy with the results. Now if I could just get the stupid cruise control to work!

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1998 E300D, 287k, barely broken in.

I would have been peeved if I would have had the head off and all I did was "blow the debris" out and put it back together and still have the same problem. Sounds like you take more cars to the junkyard, like you say, because you can't or won't fix them properly. BTW, it ain't no $1500 car.

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1998 E300D, 287k, barely broken in.

I don't think Joe will be answering you anytime soon.