Re: W140 300TD OM606.961: Steuerzeiten prüfen...
Geschrieben von pontifex am 11. Juni 2015 15:02:37:
Als Antwort auf: Re: W140 300TD OM606.961: Steuerzeiten prüfen... geschrieben von ulf r am 11. Juni 2015 13:32:38:
Servus ulf r!
Genau das ist mir passiert. Ich habe das Wundermitelchen Mobil1 5W50 verwendet. Leider nutzt das nicht viel, wenn man 30000 km damit herumfährt und wie du sagst, schlechte Kaltstarts hinlegt. Am Ende ist es dann sehr schnell gegangen... Je schlechter das MÖL umso schlechter die Starts und wiederum das MÖL... Teufelskreis.
Dennoch, der Motor hat mich NIE in Stich gelassen. Respekt!
Danach Motor ausgebaut, alles mühseligst mit Benzin gereinigt und wieder zusammengebaut. Seit dem keine Polymerisation mehr (an Holz/Schädel klopfend).
Nichts desto trotz... Ich habe wegen der Prüfung der Steuerzeiten noch das Internet auch nach englischsprachigen Anleitungen gegurgelt und bin sehr schnell fündig geworden:
http://www.mbca.org/forum/om606-timing-chain-check
Here's the method
Remove valve cover, and rotate the engine using a 27 mm socket on the crankshaft harmonic balancer nut. ONLY rotate the engine in the direction of normal rotation, which is clock-wise as you stand at the front bumper looking at the engine.
The engine has two camshafts, one for intake and one for exhaust; exhaust is on the left side, and is driven by the timing chain. Intake camshaft is on the right side, and is driven by the exhaust camshaft gear.
At the TDC (top dead center) position for #1 cylinder, all these things should be lined up:
1) Pointer on harmonic balancer points to "zero" degree mark
2) Two small (1.5 mm) divots on the exhaust and intake camshaft gears are at their closest point of approach (exhaust divot at 3:00, intake divot at 9:00 position)
3) A 6.75 mm hole at the 3:00 position of the intake camshaft gear is alined with 6.75 mm hole in the camshaft bearing cap immediately behind the gear, so that you can slide a suitable pin into that hole.
You probably will have some wear in the timing chaing and gear, so you may need to go past the zero mark to some small number, hopefully between 0 and 3 degrees. At 4 degrees, it's time to think about changing the timing chain, and at 5 degrees the chain should be changed.
The bolts for the valve cover are nominally 6 mm; as Joe points out, probably a little less than 6 mm. I just purcha-sed the "Model Year 1995 124.131 Introduction into Service". That book describes this new engine in great detail, and includes on page 22 a "Basic adjustment" which describes this 6.75 mm tool used for aligning the timing gear at TDC. The official tool is part # 111 589 01 15 00. If you use a 6.5 mm drill bit, or better yet make yourself a 6.75mm pin, you can probably get a very accurate measurement of your timing chain stretch.
Ich finde die Anleitung sehr interessant.
Liebe Grüße!
Michael