Cylinder Removal - PeachParts Mercedes-Benz Forum

mbe32094 · #1 09-27-2002, 03:02 AM

I just started my DIY cylinder head job on my car. This is my second day and already removed the valve cover, the air pump, exhaust bolts the upper front seal etc. As you can see on the picture I tried to remove the screws on the left side of the timing chain gear. The chain tensioner has been removed also but still there is no slack. So, I tried to unscrew the bolt on the flywheel gear using a T-40 torq bit. If you look at the picture it got busted.
So my next move was to to remove the lower chain rail on the right side of the timing gear. I tried to used a modified puller to pull the pin but the thread inside the pin got busted too.
My next move was to fry it out and everything went wrong. So I then I tried to fry the chain rail out a little bit and used a hack saw to cut the pin. Could anybody tell what is the name of this pin so I could order it.
Could anyone tell me also how to remove the chain fron the gear ? The chain has been marked and set the timing at 0 TDC.
This is the one that holding right now.
Tomorrow I am going to remove the intake manifold and unscrew the 14 cylinder head bolts.
Please help.

Fred

engatwork · #2 09-27-2002, 07:04 AM

man-o-man what a sight
Those fasteners in that exhaust cam sprocket should not be that hard to remove. I would try another "high quality" torx socket on them.
Your biggest headache is going to be getting that "pin" on the right hand slide rail out - especially since it is now cut at the head. It looks like a job for a machine shop now. I would proceed with removing the lower cover and maybe consider just pulling the lower pin on the right hand slide rail and pull the rail out with the cylinder head. I don't think you are going to have anything to get a grip on the upper pin with it boogered up like it is.
I would recommend replacing those wire "markers" with tie wraps that have to be cut off, that way you can be assured of not losing that orientation. I thought I remembered the chain itself being marked for proper orientation at #1 TDC but my memory leaves alot to be desired anymore.

mbe32094 · #3 09-27-2002, 12:44 PM

Jim, thanks for your reply.
I have other concern, If I unbolt the screws on the cam sprocket, can I pull the lower chain rail with the busted pin without removing the lower cover? I already decided after I pulled the cylinder head to it take to the machine shop.

engatwork · #4 09-27-2002, 01:51 PM

If I remember correctly - the lower cover has to come off to pull the lower pin on the drivers side slide rail. You are this far along - it is not really that much trouble to go ahead and remove the lower cover (in my opinion).

mbe32094 · #5 09-27-2002, 03:29 PM

Thanks again
I will update whenever I'll find something interesting with my DIY project.

Fred

Kebowers · #6 09-30-2002, 07:54 PM

Why not remove alink pin in the chain, part the chain, remove the head, and then install a master link?

engatwork · #7 09-30-2002, 08:04 PM

Ke - it is not so much the timing chain as the right hand slide rail. It is pinned in the head and the block.

mbe32094 · #8 10-10-2002, 01:24 AM

Here's the continuation of my work on my 94'E320 for installing new cylinder head gasket. Okay I got everything fixed now. I mean the busted bolts and chain rail pin .
The cylinder head was removed and sent to the machine shop. It costs me $405.00. Actually the price was $325.00 but I requested to have the cam removed and have them put the new head bolt washer. You cannot insert the the head bolt washer w/o removing the cam clamp. By the way the car has 122,000 miles on it. New valve stem seals were also installed. The valve guides are still in good shape and no need to replace them.
I have inserted some pictures and you can comment on it.

mbe32094 · #9 10-10-2002, 01:26 AM

Here's another one.

mbe32094 · #10 10-10-2002, 01:30 AM

Picture of just completed valve job. Picture reduced in size to show detail.

mbe32094 · #11 10-10-2002, 01:34 AM

Here is the job I did. Cleaned the piston head. Again the picture is reduced in size to show detail.

mbe32094 · #12 10-10-2002, 01:51 AM

The cylinder head is already in place. You don't need another body to install the head. It wasn't that heavy. I did it slowly but surely. No problem being encountered. My problem came during the tighthening of the bolts. First stage was to appyl 55 Nm on the bolts in correct sequence. The second stage was a 90 degree turn. I did followed these sequence. After the second stage I stopped and will ask for an opinion. Well on the second stage I already encountered the bolts being streched on steps 3,4 and 8. Is this okay? After a 45 degree turn I could feel the bolt being twisted/streched already. Do I have to continue to stage 3 and turn another 90 degree turn? Please advice.
Thanks,
Fred

mbe32094 · #13 10-16-2002, 12:26 PM

I got everything back together now.
After few miles of driving, I don't see any oil leaking from the engine anymore. But, there are problems. The car is idling very roughly and the engine is shaking. Also, I noticed that it has lost power. The idle RPM is normal below 1000.
This is what I did after I encountered these problems.
1. I replaced the spark plugs with Bosch super plug from MB dealer.
2. Replaced one of the vacuum hose under the intake manifold because I thaught it was leaking vacuum.
3. Checked the voltages on the fuel injector plug while the engine is running ( 12+ volts).
4. Measured the resistance on the injectors pins (15 ohms).
5.Measured the spark plug wires (1.7 to 1.9k ohms).
6. Watched the valve while the engine is being cranked, to make sure it is operating properly. They're ok.
7. I checked the diagnostic code and I got a reading of number 7 and 10. Number seven according to the manual is ignition system failure. Number 10 is mass flow air sensor. Maybe it senses when I disconected the intake pipe (top of the engine) while cheking for spark plaug voltage.
8. I tried to remove one spark pug wire one at a time to see if there is a change is the idle.
a. Number one plug wire removed ( no change in idle),
b. Number 2, 4, and 5 (also no change in idle).
c. Number 3 removed the engine dies.
d. number 6 removed the engine dies also.
9. I repalced the seals on the fuel injector. I also cleaned the injector tip by sprating it with an intake valve air cleaner sparyer.
10. I checked the coil to if there is a presence of high voltage. While removing the spark plug wire I saw high voltage spark coming out.
11. I checked the compression on the piston cylinder and I got a reading of 150 to 170 PSI on all pistons.
12. I checked the top dead center of all the pistons and here what I found.
OTDC - 1 and 6
120 - 2 and 5
240 - 3 and 4
The cd manual says at 120 is 2 and 4 and 240 is 3 and 5
When I removed the timing chain I followed the manual and marked the cam gears and the timing chain. Put the engine at OTDC. They were put back together on their proper markings.
What seems to be the problem causing the rough idle and loss of power?
Any advice is very much appreciated.

TomLatos · #14 10-16-2002, 01:56 PM

I hate to mention this, but there is always a possiblity that the engine wiring harness has failed as a result of moving around the wirng upon head removal. If the harness has a date code (located on the harness behind the battery) from 94 or so, it should be considered a suspect.

mbe32094 · #15 10-16-2002, 04:06 PM

Tom,
There are wires exposed at the end of the fuel injector plugs. What I did was I used a friction tape to cover the exposed wires and making sure the wires do not touch each other. I also retape the wiring harness with the same unsulation (friction tape) tape used by MB. By inspection the wires are bright copper in color and there is no sign of discoloration yet. But I will check the date code and re-examine the wiring harness again. Any other possibilities what causes the problem? I need help.
Thanks,
Fred