93 300CE 104 engine cylinder head removal, warning
 

Hello MB techs I would like to know of any advise, when removing the cylinder head, car has 120K miles. It is leaking oil from head gasket, engine was running very good, but due to mileage, I will have the machine shop do a valve job. Also we had codes 5 and 26, I will clean EGR passages. We just replaced engine wiring harness and spark plug wires. Thanks in advance

Whenever pulling the head on a 100k plus mile engine, I usually tell my customer that it is also a good time to replace the chain/tensioner.

mark your chain to the gears, install upper fr cover rail after
installing tensioner, and just replace the egr pipe

And no matter what anyone says, be sure and use a head gasket from MB. They have added Stainless inserts into the gasket at the front areas that leak.

AND that special gasket is make only by ELRING!! WE replace the metal EGR pipe because unless you let it soak for a couple of days the "bends are next to impossible to clean.
Also if the inside of the pipe is scratched then it will clog up very quick!

If your lower timing cover is leaking now is the time to reseal.
Make sure you clean the timing cover and block very well and use the gray permatex not the cheap red sealant . Never have had any comebacks with the gray stuff. I always replace head bolts also. :D

Watch the dowel pins for the intake.They often fall out during removal and can fall into the intake port.Whoops!!!!!

All good advice, but I don't advocate the valve job on the 104. The way it is set up, the valves are pushed straight down by the lifters, therefore, you don' t have the side to side wear like the 103. How many 104's have you seen oil consumption complaints on? I have seen none.

The only time I send the head out for work is in the case of overheating or damage.

I do advocate the valve job. Valve stem seals wear out. Valve seats distort. Valve faces distort. I have seen this mostly on overheated engines. Some high milage cars will require this work as well. In spite of the popular opinion that these guides don't wear out, I have had occasion to replace them due to wear. You will never know unless you check these items.

If you pull one of these heads and check it, it will probably need to be surfaced. These heads new from the factory are warped slightly. Do they store them on their end?

93 300CE 104 engine completed job
 

Hello MercedesTechs The job is finished on the 104 engine, they did a valve job and replaced the exhaust and intake valve guides, also replaced the front crankshaft seal, rear engine seal, engine oil pan gasket, egr pipe and ignition coil for cylinders 2, 5, due to failure after driving 60 miles(testdrive) Now the car is running very good. I would like thank everybody that sent me messages and advise. RudyBrandes

Question
 

Any objection to my moving this thread to tech help?
There are now many members who need this data.






Thank you, and have a great day.

Seeing that this is not a high tech thread and well within the scope of the more accomplished DIYs, I second the idea of moving it to Tech. I have one additional comment. I have been called to a couple of general repair shops to diagnose broken cams after the work is completed. It turns out that many people are not aware of the fact the chain tensioner has to be run all the way through and re introduced through the closing plug. The chain just sings with the tensioner is ratcheted all the way forward.

Moved from Techs Only
 

Moved from Techs Only

Bump