What are these for and yet more advice required!

[simon_wall69]

I have started to take the inlet manifold and egr off the w124 e300td om606 as (I think anyway) this was getting gunked up and causing issues. Gave up temporarily due to impatience and difficulty with removing all of the torx bolts!

There is an unbelievable amount of carbon in the manifold - up to 1.5cm thick in places!

First question: what's the best way to clean this out?

Secondly, what are the parts 30,31,56,50 and 53 there for? No real need to know, I'm just intrigued.

 

[rpe2]

I think that the parts are part of the breather assy.

If you haven't already seen it, this thread by Parrot may interest you

http://forums.mercedesclub.org.uk/showthread.php?t=25922

 

[Number_Cruncher]

Yes, they're the crankcase breather system - they're important!

It's worth taking some time and care to make sure the crankcase breather system is clear - especially for the rearmost cylinders.

The oil fumes which come down the breather system provide almost all the lubrication that the inlet valves get, and inlet valve seat recession on the rear cylinders of OM606s is a serious problem.

For the OP, look carefully at the deposits in the inlet ports - if the rearmost ones look more like exhaust deposits, it's likely that the inlet valves have sunk.

One way to check is, first plug the vacuum pipes which you disconnected, then make sure nothing's loose near the inlet ports, and then, start the engine. If you see exhaust gas coming back out of the inlet, you know the inlet valves on that cylinder aren't closing properly.

 

[simon_wall69]

I'm going to have to replace them as a couple broke as I was removing them.

I have had the car running and there is no exhaust coming back through the valves.

You were right about the grime in the manifold and I am simply staggered by the volume - especially in the egr valve, I'm incredulous that it worked at all beforehand.

 

[Number_Cruncher]

Yes, the rubber elbows tend to go brittle after a bit. I'm sorry, I should have warned you about them.

You'll also have a good opportunity to replace the plastic clips for the metal pipes to the injectors, the flexible leak off pipes from the injectors, and a good opportunity to check the wiring harness near the rear of the engine for insulation degradation.

I'm happy for you that you didn't find leaking valves. When I found mine, during the simple job of replacing the low pressure fuel lines, I was pig sick. It took a good few hours and cups of tea for me to gear myself up to taking the head off!

 

[simon_wall69]

Will do, I'm looking forward to getting it back together and seeing the difference it makes.

There is no chance of me taking the head off. Did it once on a 1983 Granda and I would imagine the Merc is a little more involved than that was!