Diesel injector duct oil leak, advice needed!
#1
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'01 W210 E320 CDI
Diesel injector duct oil leak, advice needed!
First of all my 604.012 4-cylinder engine is just a shorter version of the 606.012 300D you have in the US. The build is the same, as are most parts.
I already noticed an oil leak at the rear of the valve cover a few months ago, but now I need to fill about a quart every two to three weeks. I removed the plactic cover and found an oil bath. Upon cleaning the entire head with degreaser, there are oil droplets splashing (making a crackling sound) from the bottom of the rear injector duct.
I'm guessing the bottom of the injector-duct, with the injector and pre-chamber are screwed into the cylinder head and thus there's no oil below them. Unfortunatly all parts are drawn above the valve cover! It seems there's an O-ring sealing between the cylinder-head and the valve cover. #125 on the parts-pic I'm posting. Can anyone possibly confirm this is what I need to replace? Or can it be a more serious problem?!
Oil leak from the hole/duct, see arrow:
![](http://members.home.nl/lancelot/oilleak1.jpg)
O-ring described as "SEAL RING
CAMSHAFT HOUSING TO CYLINDER HEAD" (part# 125):
I already noticed an oil leak at the rear of the valve cover a few months ago, but now I need to fill about a quart every two to three weeks. I removed the plactic cover and found an oil bath. Upon cleaning the entire head with degreaser, there are oil droplets splashing (making a crackling sound) from the bottom of the rear injector duct.
I'm guessing the bottom of the injector-duct, with the injector and pre-chamber are screwed into the cylinder head and thus there's no oil below them. Unfortunatly all parts are drawn above the valve cover! It seems there's an O-ring sealing between the cylinder-head and the valve cover. #125 on the parts-pic I'm posting. Can anyone possibly confirm this is what I need to replace? Or can it be a more serious problem?!
Oil leak from the hole/duct, see arrow:
![](http://members.home.nl/lancelot/oilleak1.jpg)
O-ring described as "SEAL RING
CAMSHAFT HOUSING TO CYLINDER HEAD" (part# 125):
![](http://members.home.nl/lancelot/oilleak2.jpg)
#2
I wish I could help you on this one. I've never encountered a problem on this area of my engine before. I'd suggest posting this on the www.peachparts.com website as well. There are more dieselheads on there that can probably help you.
Quick question: Are you sure the leak isn't coming from the black cylinder/rubber piece right by the injector? Just something to check.
Quick question: Are you sure the leak isn't coming from the black cylinder/rubber piece right by the injector? Just something to check.
#3
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'01 W210 E320 CDI
No the rubber piece (knee-shaped) is the first part I replaced. The oil leak is really coming from deep inside the injector duct. What I'll do is order the O-rings and valve-cover gasket from the dealer next week and take it apart. The only thing I'm worried about is getting leaks from the metal fuel-lines which have to be removed and reinstalled...
#4
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What you are describing is usually oil leaking from the CCV (black hockey puck) or it is diesel mixed with oily residue from a leaky cloth braided return line.