Om617 valves? Again yawn but!
 

Ok so I have a motor in a sedan that was sat for years
I adjusted the valves as they were all tight I've driven it maybe 300 miles it's now smokey uneven but when driving seems to go ok
And appears to only smokes at idle

I swapped out some injectors which made it a bit better but how often after not being adjusted should I re adjust the valves?

I have read that this condition could be knocking off the carbon so they will need adjusting again allready but... should I drive it hard for more miles first or add anything to fuel or oil?
Can I fit new stem seals without pulling it to pieces?
Thanks

If it helps here's some more info
79 n/a runs ok with occasional miss was smoking before adjustment but I put that down to being sat for maybe 10 years plus bad valve adjustment etc
Diesel purge smooths it out and helps the smoke
Would marvel oil help? Just looking to free up any rings and clear out the carbon

Oh and it's breathing out the oil cap but seems reliable and ok when driving miles say 260 compression tests were acceptable

Diesel discussion
 

You might have better luck posting and Diesel discussion

Darn it my mistake thanks

Compression is 260 p.s.i. ? That's on the bottom end of "acceptable". The beast is tired. Use a cetane additive and drive it until it quits. Then throw another engine in it.

4 Best Diesel Fuel Additives of 2018 (And Why They Work)

Per Mercedes FSM for a 617.950 Turbo (im sure the NA would either be very close or match

Normal compression is 319-348psi
Lowest acceptable compression's 218psi


Maximum difference between cylinders is 44psi