I replaced the head gasket on my 87 300D last week (a very long ordeal due to a broken head bolt, broken exhaust stud, and bent turbo oil feed line), and now it starts OK, but rattles horribly and makes white (fuel) smoke at idle. No smoke under load, coolant holds OK (I think, need a new upper radiator hose). Very smooth idle and lots of power, just far too much smoke and injector noise.

No cracks in the head, not warped that we could find (foolishly didn't take it to a shop for a real check). The previous installation was bad -- I know that MB does not used "copper sealant" on heads and it was present on some cylinder seal rings, and the gasket was the original type (no re-enforcement at the front oil passage and no viton ring on the rear oil drain). Sloppy installation with used bolts, possibly not torqued correctly, had compression "sharing" between #4 and #5, serious oil leaks at the front and into the coolant, and leaking compression out the back side of #6 into the bolt hole, freezing the bolt which then broke off when we tried to remove it. #14 head, either the original or a replacement at 160,000 miles or so -- had a new rad in it when I got it.

It sounds to me as if the injection timing is late, although I suppose it could be uniformly low compression. Engine rotated easily by hand, cam timing is OK (at least my brother said so, I need to check again). Chain is an unknown -- read 2 degrees stretch when I took the cam out, but that doesn't mean it wasn't worn long before I got the car (I've put 100,000 miles on it).

I'm thinking a new chain, since it has at least 100,000 miles on it, and then setting the timing corretly. The injector noise goes away about 1200 rpm and so does the smoke -- makes me think late timing. I don't want to run it any more than absolutely necessary until I figure this out.

Thanks!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

An update:

Finally got a full fill of coolant in it (I used Shout to get the oil out, took about 9 gal of water to get the soap out...) and actually drove it some. Noise is much less and there is only slight smoke at cold idle, none warm, so I guess it's just higher compression and air in the lines.

I still have to replace a couple injection lines -- the clip on 4,5, and 6 under the intake was gone, and the lines were rubbing together under there. I'm quite suprised neither one has blown yet, they look like they are about half way through!. New ones Monday, along with the upper radiator hose that will not seal. New overflow lines, too -- it drives fine, but leaves a trail of diesel fuel from the pans underneath...

The difference in running is amazing -- idle is VERY smooth, and it's much quieter due to a non-leaking exhaust manifold....

I'll be glad to have it back, the 280 is getting a whopping 14 mpg!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!