BenzWorld Junior Member
Date registered: Nov 2012
Vehicle: 1990 300e
Mentioned: 0 Post(s)
Quoted: 2 Post(s)
Please Help - crankshaft turns only 1/4
My thanks goes out to you all for your many posts - I have learned a lot from these forums:confused. I have a 1990 300e that was running pretty good but decided to replace the cylinder head and change the gaskets to solve some oil burning & leaking issues. This is the first time attempting something of this scope, but after researching job online & with haynes in hand, undertook project. Took necessary parts off & with assistance from brother, carefully put rebuilt head onto fresh gasket after a couple trial runs - went on fine & then torqued in head bolts to spec.
Then I attempted to use 27mm socket to turn to TDC, but the crankshaft will only turn 90 degrees - a quarter turn - also will only turn CC to original starting point. The camshaft is not even in so pistons can't be hitting valves. Thought that though I was careful suspending the timing chain it had somehow got bound up - tried maneuvering it while turning crankshaft back & forth - of course even being careful I ended up cracking timing chain guide. So I proceed to take off everything needed to remove lower timing chain cover to check possible bind/replace guides. Finally reach that stage & find chain is not jammed. Took off broken guides & chain is now hanging loose - not even on sprocket to cause a problem. The crankshaft will still not rotate more than 1/4 turn - spark plugs are not even in so it is not a compression issue - its like hitting a wall after a quarter turn. The car was in park, but also tried to turn while in N. I am baffled what could be causing this - does anyone have any ideas? Much thanks in advance.