W123 M102 engine - heavy breather

Peter C1974

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Further to this post: http://forums.mercedesclub.org.uk/showthread.php?t=86218&highlight=w123+engine

The mileage has gone up by 20k since the above post and the engine is still running fine but I suspect it is breathing heavily.

Symptoms:

1. Oily smell from the exhaust.
2. Oil loss. Approx a litre per thousand miles.
3. Slight deposits of oil around the filler cap.

Positives:

1. Engine runs and pulls well.
2. Apart from a puff of blue smoke in the morning, there is no evidence of blue smoke (burning oil) during normal driving.
3. No oil leaks.

Apart from the breather pipe arrangement that I have cleaned and modified (see post above), does the M102 engine have any other crankcase ventilation pipes or valves?

Peter C
 

DIYMAN

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The blue smoke on start up can be indication of worn valve stem oil seals. When I had the same engine I did a decoke and fitted new valve seals, after that I never had to top the oil up between changes.
 
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The blue smoke on start up can be indication of worn valve stem oil seals. When I had the same engine I did a decoke and fitted new valve seals, after that I never had to top the oil up between changes.

Second this, these engines and 103 were very prone to the seals hardening, can be done in situ with the right tools.
 
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Peter C1974

Peter C1974

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Thanks guys, I'll look into it.
 

Alex Crow

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As above re. valve seals, used to change the, all the time on the 102/103, and not too bad a job if care taken and in-situ valve spring compressor available.
Never forget to make sure each cylinder is at TDC when removing collets though!
 

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As above re. valve seals, used to change the, all the time on the 102/103, and not too bad a job if care taken and in-situ valve spring compressor available.
Never forget to make sure each cylinder is at TDC when removing collets though!

We do ours at Bdc, with compressed air holding the valve up and piston down. Either way is good.
 

Alex Crow

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We do ours at Bdc, with compressed air holding the valve up and piston down. Either way is good.

Actually, your way is better, but you better hope the collets are not too tight!
 
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