How to stop MAF oil contamination (CLK 230K - W208)

[tochnia]

Can you please recommend some independant garage/service can fix same Oil problem on MAF on my CLK 230 /W208/ on reasonable price?

I'm looking for West/North London or up to 20-30 miles away, and I have already bought all needed parts from dealer.

You will probably ask why not DYI, but I don't feel comfortable with removing myself fuel line and all parts to get to tubes/hoses which need replacement /in the bottom of the photo/:
http://farm8.staticflickr.com/7438/12037742394_19c222b9fe_z.jpg

 

[television]

WG in Harrow, a very good man.

 

[db1]

R171 Breather non-return valve - which way round ??

As a follow up I would add that I have now covered another 55,000 miles since replacing the breather system under the inlet manifold without a single misfire or MAF problem.

Jim

Congrats on your thorough work on the 111 breather system. Wonder if you can tell me which way your 111 breather valve is connected please.

Just stripping down my R171 200K to replace the timing chain for preventive reasons. On removing the intake silencer ducting i have found a build up of engine oil on the ledges inside. I decided to examine the breather pipes, so have removed the intake manifold and Kompressor. It looks as though someone has replaced the long upper pipe as far as the restrictor nozzle (only1 on the 171). However they did not remove the Kompressor to get to the other 2 pipes and the 1 way valve.

What I found as I removed the Kompressor was that the pipe immediately under the restrictor nozzle, leading to the 1 way valve and then the sump, was not connected - no clip is fitted and it had slid off or was blown off by crankcase ventillation.

Can you tell me from your 111 (or anone with a 271) which way around should the 1 way valve be fitted. On the 271 engine the 2 connections are the same size, so theoretically it could be fitted the wrong way round. ???

Love the forum and the help given.

Thanks guys

 

[Jeffthenorm]

It is believed that the info also applies to all W202 (C class) Kompressor engines.

History behind this.
There have been a few discussions in the Forum about MAF failure on the W208. This post covers the failure of the MAF - by oil contamination.

If your W208K has a mileage in excess of 90,00 miles
This is one job that you should carry out in the near future as a matter of preventive maintenance.
In excess of the above mileage even if your car is not suffering from this problem now it will, which is exactly why I did the job anyway.
The parts are cheap in comparison to replacing dead MAF sensors.
If you cannot do the job yourself approximately 4 hours labour should be allowed for a workshop to complete the job.

One Forum Member carried out a lot of research on the problem and, along the way, dispelled one particular myth quoted a few times in the past :

If your W208 (W202) has oil in the Air filter housing or any pipework leading, via the intercooler, to the MAF
then it will not be Kompressor (Supercharger) related failure causing the problem.​

The reason for this (as pointed out byjiminessex) is that, unlike a turbocharger, there is no oil feed from the engine to the Kompressor. The only oil the supercharger uses is held in a tiny inbuilt reservoir within the compressor body itself. This quantity of oil alone is insufficient to cause oil contamination to the point where it reach the MAF.


So, if it isn't a Kompressor (Supercharger) fault what causes the MAF oil contamination problem?
The research by jiminessex answers that:


Summary
The idle to upper partload oil breather system is blocked and forcing the highload oil breather system to accept the excess oil residue at low airflows.
The excess oil is then being dumped into the air filter housing then travels via the intercooler and associated pipework to the MAF.
The MAF dies!


The DIY repair. as carried out by jamesmc

Parts to be ordered prior to the work:-
1 x Main hose - MA111 018 15 82
1 x Valve/Tee-Piece complete - MA111 010 00 91
2 x Small bore hoses - MA 002 094 01 82 (supplied to me as one double length hose that I chopped in half)
2 x Nozzles - MA111 017 00 12 (These are brass)
1 Set (pair) of inlet manifold gaskets. Sorry no part numbers. These are more like silicone 'O' ring material rather than traditional flat manifold gaskets.

Tools required
A good DIY mechanics toolbox with Metric socket set will cover most of the work
Plus: Torque Wrench & Reverse Torx Sockets (for fuel rail/manifold bolts)

The Job
I haven't gone over every finite detail here but it stands to reason that any cables/connectors that hamper access along the way need to be disconnected.

• Disconnect any necessary pipework... fuel lines etc. from the fuel rail.
• Remove all the inlet manifold bolts including the two extended reverse torx bolts which, as well as securing the fuel rail, also act as manifold securing bolts.
• Ease the fuel rail out of the way
• Ease the manifold off and away from the head to one side, but don't remove it completely.
  Pulling the manifold away from the head and to one side a little gave me enough access to do what was needed. I suspended the bulk of the weight from the bonnet using bungees so that (in effect) it was floating, almost weightless, to one side.
• Remove the two small bore hoses along with the 'T' piece and the main hose.
  Both of the small bore hoses (MA 002 094 01 82), which connect to the underside of the nozzles (MA111 017 00 12), were brittle as mentioned earlier in this thread, hence the need to ensure you have all the parts required before getting stuck into this job.

The brittle small bore hoses simply snapped off with very little effort.
Look in the images below and you will see the original small bore hoses fitted with the 'T' piece in place​

• With a pair of small light duty side cutters snip off the rest of the brittle hose remaining on the underside of the nozzle tube connectors.

On inspection, and with a squirt of WD40 via a small tube up the disconnect nozzles, I noted that the forward brass breather nozzle was about 90% clogged and the rear nozzle 100%. So not a lot of breathing going on there!

This is the forward brass nozzle that was about 90% blocked
You can also see the original small bore hoses and 'T' Piece in place​

Another shot of the forward brass nozzle that was about 90% blocked
also showing the original small bore hoses and 'T' Piece in place before removal

Looking directky from above at the rear brass nozzle that was 100% blocked​

After inspecting the existing nozzles, even though I had two new replacements, I decided to leave them in situ. In my mind that was the safer option rather than trying to extract brass from aluminium that had resided (mated in that position) since they left the factory in 1999.

• Check the bore size of the new nozzles and select a drill bit that matches the bore size.
• Clean the existing nozzles out in situ using a small drill bit held by hand only. I also used tooth picks and WD40 to flush out the debris. End result? Two clear nozzles to original spec.

The Valve 'T' Piece (MA111 010 00 91) looked a bit choked up too when I investigated further. It could be cleaned I guess but the cost of a new one is minimal.

• Replace the inlet manifold gaskets with two new ones and reassemble.
• Intake Manifold Bolts are torqued to 20Nm as recommended by MB.

Additionally:



Extra DIY pointers: How to Clean your MAF by Parrot of Doom


For further reading check out thread Oil In Air Intake thread

Hi does anyone know if the parts listed are the same for 2005 clk a209 200k