w203 220cdi annoying oil leak

[e55amggary]

AS title suggests i have an oil leak around the oil filler cap and crankcase breather that the cap screws on too.

I have replaced the oil cap with a new mercedes cap, the oil still seems to be coming out from the cap though? I have bought a new o ring for the oil breather which i am going to remove and clean.

Can these become blocked ? Are they a serviceable item ? Could this leak be something else ?

Anything else i should be checking ?

Fitted new washer pump today which was easy enough, so another little job out the way.

Many thanks

 

[Droverunner]

I'm glad you asked this as it's something I've forgotten to query and I'd be pleased to hear what folks have to say.

We don't have any pressurisation signs yet but at 100k plus I'd like to locate and check/clean/replace the breather. On my 6cy BMW diesel this has a felt type filter which is usually ignored for years and does give problems.

 

[e55amggary]

Very familier with the bmw set up inc the vortex breather system. Just wondering if i can take off the crank case breather and wash it through. I know they are around £80 from merc.

 

[Droverunner]

Yep I'd be looking at washing it through assuming that can be done.

 

[e55amggary]

Had time to kill.

Removed breather today.No blockages , i could blow through it easily. The large main o ring had become very hard with signs of leakage. I cleaned / replaced this.

The smaller grommet i also replaced, the replacement from Mercedes was slightly different. Smeared with a little vasaline , put back together.

Will report back

 

[e55amggary]

Well , been for a run today. All good on the oil leak situation. Everything seems nice and dry.

Part no.s MA029 997 88 48 (large o ring) MA646 016 10 21 (small grommet) Must of been oil vapour escaping getting things damp ?

Job worth doing

On another note Thermostat pooped, have one ordered anyhow. I know these can effect mpg so worth doing. Few more niggles and the car will be up to spec

 

[Droverunner]

Thanks for reporting back. When I have a moment I'd clean ours out.

Re stat ours looked OK-ish by the temp gauge but then checking live temp data from our iCarsoft i980 soon showed the old one was erratic and when I took it out found it wasn't closing fully.

 

[e55amggary]

Our stat is staying open. On the motorway it only reached 70. Came off, stood in traffic, just got to 80.

Had a om646 in a w203 a while back, so i know these need to get to temp or they will drink more fuel

 

[Droverunner]

Not the end of the world but we badly misjudged the likely fuel consumption of our 220CDI CLK. The routine cross country commute Mrs D travels and her keen driving is pulling the fuel consumption to around 33mpg... on a longer run she's getting 42mpg though.

With the iffy stat we were seeing 28mpg on shorter runs.

As a comparison you can tear the pants off my old 5-series tourer with the 2.5 6cyl diesel and 40mpg is still seen... 50mpg on a run.

 

[Wighty]

Not the end of the world but we badly misjudged the likely fuel consumption of our 220CDI CLK. The routine cross country commute Mrs D travels and her keen driving is pulling the fuel consumption to around 33mpg... on a longer run she's getting 42mpg though.

With the iffy stat we were seeing 28mpg on shorter runs.

As a comparison you can tear the pants off my old 5-series tourer with the 2.5 6cyl diesel and 40mpg is still seen... 50mpg on a run.

That does seem a touch low , especially as this was from a c200 Kompressor recently

 

[e55amggary]

My previous w203 c220cdi sport was a 6 speed manual. Had it re mapped and it was great on fuel, easily over 50mpg on a run. Much quicker also than the auto

The missus has grown to like the auto though.

I can get 45mpg + from my A6 avant quattro sport, and that shifts ( 2.7tdi)

 

[Droverunner]

A touch lower than we were hoping for but probably correct for her usage and journey type. The book figures for our CLK are approx 30.7, 40.7 and 50.7 mpg. The fact she can make just above the combined figure on a mixed longer run herself indicates there is no fault to search out. Her commute at 33mpg again is probably about right given it's along country roads with many corners, 30 limits and junctions... so just above urban is about right.

I think the surprise was just that she moved to the CLK from a car with an urban nearer 56mpg.