Having NO experience with this engine my thinking is that if this came on suddenly you probably have a better than 50/50 chance that is a cylinder head or gasket problem. The reason i say this is having read a number of posts about the "rod bender" my understanding is that the bent rod causes the cylinder to wear to an oval shape and ultimately the worn cylinder and piston rings allow lube oil to pass to the combustion chamber and cause smoking.Logically this would be a gradual process with first a little smoke then increasing to eventually alot of smoke. I would think the bad cylinder would show up on a compression test,but then so would a bad gasket! Boils down to what has already been said ,get the head off and see whats going on. Don

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Red Green "This is only temporary,Unless it works!"

97 E300D 157000 miles
87 300TD ?141k? miles