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  #1  
Old 01-05-2007, 05:14 PM
Craig
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Originally Posted by captainmonk View Post
best fix for a lil blue smoke is not lookin out the back window .....
LOL, that's good.

Seriously, if you are planning on keeping the car just have the head done.
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  #2  
Old 02-01-2007, 05:15 PM
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Three different length head bolts....

Where do they go? Before I took the head bolts out, I glanced at the FSM and thought, "oh, well they've got drawings that'll show where each goes." Well, turns out the FSM gives a hint that the shorter ones go near the injector holes, but does anyone know where the other two length bolts go?
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  #3  
Old 02-01-2007, 07:56 PM
t walgamuth's Avatar
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the long ones go through the cam towers, iirc.

the really short ones go inside the cam chain housing.

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.
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  #4  
Old 03-03-2007, 09:48 PM
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Update: Thanks a bunch to everyone's help. I have about 300 miles on my new head from Metric. Tailpipe smoke hung around the first 100 miles and I got worried that I didn't fix much. But started fading and now I can observe that the new head has reduced my once embarrassing tailpipe smoke down to a gentle whisp. So far, can't observe any significant oil burning (Prior to new head, I'd have burned a half quart by now). I switched to Mobil 1 TD 5/40, so maybe that is contributing to that and the lesser amount of smoke--don't know for sure. The valves were shot! Carbon on everything under the guides. Couldn't tell if valves were actually burned, but they were definitely not seating with all that crap everywhere. Not even the ballsiest Italian could tune that one up! A few of the valves I could actually feel play in the guides. The car is much peppier now and starts right up in the a.m. I kinda wish we'd get a cold snap down in the teens or lower to see how she'd do--coldest we've gotten since the job has been down to 29 or so and fires on first crank.

Thoughts on the job itself. Not bad for moderate to slightly advanced mechanical ability. Takes a while, so I'm fortunate to have the Camry safety net car. Here's a few tips that I hope would help someone contemplating doing the same job I did. You seasoned veterans can stop reading right here, but if you've never done the job and you're contemplating it, perhaps my trials and tribulations can help. Manifolds should stay on when you pull the head--just makes it easy. Pull the head with an engine hoist. Remove fan and turn engine clockwise only with a 27 mm deep socket. Don't fool with turning with power steering pulley--that thing has to be removed for the job anyway. Paint marks on cam and timing chain and DO NOT rotate engine with cam gear off of timing chain. When turning engine over by hand, plug the chain tensioner hole with a rag, because that thing gets major oil pressure that spews out even just doing it by hand. Oh, FSM says to loosen up oil filter housing cap, but they don't say why. It's to let the oil in there drain to the pan. And when turning engine by hand, this will spew oil out as well if left loosened up. Don't worry about keeping tension on the timing chain while pulling the head out or after it's out--just lay it to the side (I laid it to the side and just to keep it out of the way tied it off with a bungee cord to the fender well). When loosening the cam gear bolt, block the back of the cam, because when that bolt comes off and there's no rockers holding it there, it will slide back and the timing washer will drop into the timing cavity. If that happens or if anything else drops down there, just close the hood and walk away until you're ready to continue which will entail pulling the engine. The IP and crank down below don't let go of the chain very easily. The rockers come off and go on in one position of the cam. If you're not on the right position, forget it. Keep turning. Seems to me the first set was about TDC or close on #1. And the second set was way beyond that on #4 or #5. But, reminder, don't do that unless you've got the cam gear on with chain attached. And when you're all done, turn the engine over 720 deg. just to make sure no valves are hitting pistons. Finally, keep plenty of Scotch around--satisfaction that it'd probably piss off a German Benz engineer that you're wrenching on his creation while savoring the drink of the technologically inferior Scottish.

Whew, I think that's it. If I think of anything else, I'll be sure to update. And thanks again to all you on this board that helped me out. I couldn't have done it without you.
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  #5  
Old 03-03-2007, 10:34 PM
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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.
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  #6  
Old 03-04-2007, 09:25 AM
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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
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  #7  
Old 03-04-2007, 08:34 PM
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Quote:
Originally Posted by 240Joe View Post
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
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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  #8  
Old 03-04-2007, 08:25 PM
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Originally Posted by t walgamuth View Post
good work.

glad it is working out for you.

tom w
Thanks, Tom, you've been helpful.
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  #9  
Old 03-04-2007, 11:21 AM
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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.
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  #10  
Old 03-04-2007, 11:58 AM
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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
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  #11  
Old 03-04-2007, 12:30 PM
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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.

Last edited by barry123400; 03-04-2007 at 12:36 PM.
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  #12  
Old 03-04-2007, 01:23 PM
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Quote:
Originally Posted by 240Joe View Post
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


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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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,
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  #13  
Old 03-04-2007, 02:05 PM
t walgamuth's Avatar
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Originally Posted by 240Joe View Post
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 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.
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  #14  
Old 03-04-2007, 02:30 PM
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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
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  #15  
Old 03-04-2007, 02:30 PM
Craig
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Originally Posted by t walgamuth View Post
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
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.
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