M112 Head Gasket Replacement
 

I have a 1998 Mercedes E320. What is the proper order of reinstalling the engine heads? Engine heads first, then the front cover or the other way around? If there is more info/PDF on this, point me in the right direction. Thank you.

per the procedure in Alldata, which is some sort of copied version of WIS, you don't need to remove the timing cover to remove the cylinder heads.
What did you do to the heads? Gasket replacement is a rare item on the V6.

if you are removing the heads and your timing chain rails are old - without a shadow of doubt renew the rails and chain too.

The procedure I have seen is timing case after the heads - there is a youtube video of a russian mechanic assembling an M272 - its the same procedure.

Thank you guys for your response. The car had a code, p0410 the air pump cannot blow air through the heads. It was extremely clogged, thats why I removed the heads. Plus I had the oil in expansion tank. And my timing chain was making a noise, car have a 190 miles. When I removed front cover there was two coolant O-rings, one ring expanded and went into the engine head and got stuck. Thats were the coolant leak, but the head gasket was ok.

good call on removing the heads if you had all those issues.

timing chain guide rails replacement requires removal of the heads anyway and make sure to use proper sealant on the timing case and head gasket edges, It was originally bonded with loctite 5900.

If you had only the air pump problem - then many mechanics have repaired that fault with a liquid product made by BG I think and some people online have also used combustion chamber cleaner also.

Thank you for your response!

Here is list of parts I ordered. Did I miss anything?

I am still thinking if I should replace the camshaft and crankshaft sprockets because the rubber is in a bad condition or not? What's interesting is M113 does not have rubber on the sprocket.

If the rubber on the sprockets are still ok then no need to change them I think.