HeadGasket Question help!!!!!!
 

I have a 1991 e300te 4matic and I am in the process of replacing the headgasket!! I have the intake and exhaust manifolds unbolted and all 14 head bolts are removed and the head is ready to come out. I am stuck at how to take the head off with the timing chain attached. I do not plan on replacing and am sure you can take the head off but I need clarification. The car has 188,000 miles on it and would like to know what else I should be doing since the head is coming off. I have the headgasket kit which I bought from a MB dealer. Thank you in advance for any help!!!!! :confused:

mark the chain in relation to the sprocket (i.e. with white out) and take it off the gear.

<<The car has 188,000 miles on it and would like to know what else I should be doing since the head is coming off.>>

The chain, If original.
I see you want to save the one in there , so I assume you have already changed it in the past ???
If not , that is a definate at those miles and cost.

On most MB engines, Arthurs recommendation would be valid, but not on the 103. This engines timing chain system is simple and bulletproof.

Marking the chain as it relates to its cam sprocket position may get you in trouble. If it were to slip on the crank sprocket during the process, you would be out of time. One notch retarded will make the engine run bad, one notch advanced will cause piston/valve contact!

Before removing cam sprocket, turn the engine to TDC as marked on the harmonic balancer and then remove the chain tensioner. ONLY THEN should you remove the cam sprocket. Use some wire to hold the chain and have someone feed the chain and wire through the head then tie the wire off to hold the chain and keep it from dropping in the cavity.

When reassembling, put the camshaft in position on the head with the timing marks at the top of the front cam bearing stand aligned with the cam mark. Tighten all the cambearing stand bolts and rocker arm stand bolts down evenly across the head. Tightening one stand all the way without slowly running all of them down a little at a time can break the cam and strip the bolt holes.

Once the chain is back in place and the cam and crank are properly timed. Push the toothed plunger in the tensioner all the way through and out. Then start it back through slightly. When the engine starts, oil pressure will push the tensioner to the proper position. Failure to do this can cause serious problems.

Good luck,

Well, while I agree w/Larry that both 103 and 104 have a great chain histoy and set-up, If I were already in there and the engine was pushing 200K,the short $50 for a new chain would certainly be on my list.
But, at the same token, I also would not go and tear one down just to satisfy the common Benz chain paranoia..
It's a judgement call and if you see any other wear items that indicate poor maint./oil changes, you may want to consider it .. all parts wear out.
PS.
Do heed Larrys tensioner tip.. these units ratchet and lock in length as the chain wears to keep the tension from releasing when there is no oil pressure
[ engine at rest]. This is one of the reasons for lower chain failure on these type systems. So, the tensioner has to be reset when doin any work , such as head or chain change.
There are post here in the archieves where this was not done and camshafts were broken due to to tight of chain tension. A simple, costly oversight...

Something else: You have to either remove the upper stud that the timing chain guide rests on, or pull the front timing chain cover off and remove the guide altogether. Pulling the stud requires a special MB tool that is like a slide hammer with a 6mm bolt, although others have managed to remove it with other expediant means. Myselt, I pulled the front timing cover and replaced the chain tensioner and guides. The timing chain can be removed nearly any time by pulling the top cover, and using a rivet tool to temp rivet the new chain to the old, then rotating the motor by hand and draw the new chain into the motor. When you get it all through, you use the rivet tool and master link to join the new chain together...simple. I'll probalby do it around 200K miles.