Blocked breather nozzles & oil on MAF DIY fix
08-13-2012, 05:02 PM
#1
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Thread Starter
Blocked breather nozzles & oil on MAF DIY fix
I thought I would share some lessons learned from a problem I was having with oil on my MAF causing the car to run with poor performance which I have now cured.
Thanks to to this forum and from reading ''jamesmc'' post on similar issues he had, I managed to cure my problem but will add some additional advice.
The car I have is a CLK 230K and I had noticed the performance was not as 'electric' as once it once was but to be honest had got used to it. Then when I needed to accelerate one day it just was too slow and the supercharger has been intermitently working and I found if it stopped working it would come back on if I re-started the car.
All of this pointed to the MAF as the suspect, but first I had to stop the cause of the oil getting on it (Before you say K&N, this is a not the case on a 230K as the MAF is on the other side of the car). 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 and with blocked breather nozzles inside the inlet manifold means the oil gets forced the wrong way and hits the MAF.
So the fix is:
1 - Unbolt the inlet manifold along with the fuel rail and move away from the engine.
2 - If you look at my photos you'll see the build up of old oil and crudd and the small brass nozzles with a 1mm hole are completly blocked.
3 - Remove the two tubes underneath connecting to the nozzles which will probably be very brittle and break and you will need to remove the broken part left on the underside of the nozzle.
4 - I Then bought some fuel injection tube the same diameter and just made up two more new pieces to replace the broken tube from the T-Piece.
5 - Clean all the old oil from the inlet manifold, I used accetone and brake cleaner and squirted some right through the nozzles with the plastic tube now nice a clean !
6 - Re-assemble and try it out.
Unfortunately for me this is where I had to work on my MAF as despite the cleaning I had done when I reconnected the battery and performed a reset procedure the MAF was no good and the car would not run at all. It seemed the car had learned the old MAF and now the ECU was cleared it was not running. I had a spare MAF in my garage from an old E-Class which I temporaly connected up and the car idled but did not run well, however this gave me enough confidence that the MAF was at fault.
I bought a new MAF today (Boy these things are cheap these days £70! I remember spending £350), connected the new MAF and did a full reset both with the car and throttle and OMG my car is rediculously smooth and the speed is nothing I ever remembered before incredible and with the Supercharger its mental !
Website seems to be lot working with sending pics so will try later...
Thanks to to this forum and from reading ''jamesmc'' post on similar issues he had, I managed to cure my problem but will add some additional advice.
The car I have is a CLK 230K and I had noticed the performance was not as 'electric' as once it once was but to be honest had got used to it. Then when I needed to accelerate one day it just was too slow and the supercharger has been intermitently working and I found if it stopped working it would come back on if I re-started the car.
All of this pointed to the MAF as the suspect, but first I had to stop the cause of the oil getting on it (Before you say K&N, this is a not the case on a 230K as the MAF is on the other side of the car). 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 and with blocked breather nozzles inside the inlet manifold means the oil gets forced the wrong way and hits the MAF.
So the fix is:
1 - Unbolt the inlet manifold along with the fuel rail and move away from the engine.
2 - If you look at my photos you'll see the build up of old oil and crudd and the small brass nozzles with a 1mm hole are completly blocked.
3 - Remove the two tubes underneath connecting to the nozzles which will probably be very brittle and break and you will need to remove the broken part left on the underside of the nozzle.
4 - I Then bought some fuel injection tube the same diameter and just made up two more new pieces to replace the broken tube from the T-Piece.
5 - Clean all the old oil from the inlet manifold, I used accetone and brake cleaner and squirted some right through the nozzles with the plastic tube now nice a clean !
6 - Re-assemble and try it out.
Unfortunately for me this is where I had to work on my MAF as despite the cleaning I had done when I reconnected the battery and performed a reset procedure the MAF was no good and the car would not run at all. It seemed the car had learned the old MAF and now the ECU was cleared it was not running. I had a spare MAF in my garage from an old E-Class which I temporaly connected up and the car idled but did not run well, however this gave me enough confidence that the MAF was at fault.
I bought a new MAF today (Boy these things are cheap these days £70! I remember spending £350), connected the new MAF and did a full reset both with the car and throttle and OMG my car is rediculously smooth and the speed is nothing I ever remembered before incredible and with the Supercharger its mental !
Website seems to be lot working with sending pics so will try later...
Last edited by A1EK; 08-14-2012 at 05:11 PM.
08-14-2012, 05:55 AM
#2
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clk 200k
I'm glad it's working for you. My MAF is still geting wet with oil after similar intervention. I don't know what's wrong. Maybe piston rings or valve guides..... 
Maybe the guys at MB just fixed the parts I can see without dismantling the inlet
Anyway, we've talked about this before:
I doesn't matter where the MAF is. The air flow is from the air filter to the MAF to the engine to the exhaust. So, if the air filter releases oil, it will contaminate the MAF for sure.
I'll be waiting for your pics.
tx for sharing.
Maybe the guys at MB just fixed the parts I can see without dismantling the inlet
Anyway, we've talked about this before:
I'll be waiting for your pics.
tx for sharing.
04-17-2014, 02:54 AM
#3
Hi! I know it is an old thread but I am going to try this procedure myself (1998 CLK200K cabrio ) in the following days,though I am not a mechanic. I have ordered some parts and I wait for them to arrive. I have a couple of questions for you A1EK.
1)Is it necessary to disconnect the battery for this job?If yes, I guess I need some kind of reprogramming?
2)Does the fuel rail need to come of separately?Or together with the manifold?
3)In general I only need to untighten the 6(?) screws of the manifold only,clean everything and then close it?
4)Does the manifold ,when untightened, stands in place by itself or do I need to hold it so as not to fall?
5)Do I need to replace the gaskets?If yes, I just replace them, or do I need any special glue?
6)What cleaners and/or lubricants are the best for this job and where should I use them?
7)Is there anything else I forgot I should watch out ?
Thank you in advance and sory for all those questions!
1)Is it necessary to disconnect the battery for this job?If yes, I guess I need some kind of reprogramming?
2)Does the fuel rail need to come of separately?Or together with the manifold?
3)In general I only need to untighten the 6(?) screws of the manifold only,clean everything and then close it?
4)Does the manifold ,when untightened, stands in place by itself or do I need to hold it so as not to fall?
5)Do I need to replace the gaskets?If yes, I just replace them, or do I need any special glue?
6)What cleaners and/or lubricants are the best for this job and where should I use them?
7)Is there anything else I forgot I should watch out ?
Thank you in advance and sory for all those questions!
04-21-2014, 08:36 AM
#4
MBWorld Fanatic!
Thread Starter
Hi! I know it is an old thread but I am going to try this procedure myself (1998 CLK200K cabrio ) in the following days,though I am not a mechanic. I have ordered some parts and I wait for them to arrive. I have a couple of questions for you A1EK.
1)Is it necessary to disconnect the battery for this job?If yes, I guess I need some kind of reprogramming?
2)Does the fuel rail need to come of separately?Or together with the manifold?
3)In general I only need to untighten the 6(?) screws of the manifold only,clean everything and then close it?
4)Does the manifold ,when untightened, stands in place by itself or do I need to hold it so as not to fall?
5)Do I need to replace the gaskets?If yes, I just replace them, or do I need any special glue?
6)What cleaners and/or lubricants are the best for this job and where should I use them?
7)Is there anything else I forgot I should watch out ?
Thank you in advance and sory for all those questions!
1)Is it necessary to disconnect the battery for this job?If yes, I guess I need some kind of reprogramming?
2)Does the fuel rail need to come of separately?Or together with the manifold?
3)In general I only need to untighten the 6(?) screws of the manifold only,clean everything and then close it?
4)Does the manifold ,when untightened, stands in place by itself or do I need to hold it so as not to fall?
5)Do I need to replace the gaskets?If yes, I just replace them, or do I need any special glue?
6)What cleaners and/or lubricants are the best for this job and where should I use them?
7)Is there anything else I forgot I should watch out ?
Thank you in advance and sory for all those questions!
To answer your questions...
1) You should really always disconnect the battery but you can do this without doing so. IF you do disconnect, the start up procedure is simple enough.
2) The fuel rail on my car is on the right of the engine. You just need to be able to move this off the engine block to access the blocked nozzle. You may need some long or flexible socket bars etc.
3) Once you have the fuel rail seperated use some thin wire to clean the nozzles, you will probably find the rubber hose will break as its brittle when old. You should buy some new rubber hose ready if this happens. Its cheap enough, I used rubber fuel pipe for $4 that can be cut to size and is the perfect diameter to push onto the nozzle ends. Don't bother going to Mercedes to buy the actual pipe as its more expensive and no different.
4) The manifold will stay by itself
5) No the gaskets are fine to use again as they are rubber not compression paper gaskets.
6) Use anything you can that will clean the gunk, WD40 is good or ethanol spray etc. I used WD40 with the thin straw attached to blast through the blocked nozzle.
Lastly make sure you clean any oil in the MAF areas as you will then see that after you have performed the above there should be no more oil getting into this area.
Good Luck.
