Ml 270 cdi air filter

[Andy Wr]

Today I changed my air filter from a K & N filter element which was in the car when I purchased it to a standard MB paper filter. Whilst in bits I noticed how very dirty the k & N filter was and in 1 area was covered in thick dirt, I obviously cleaned the air box out, cleaned the gauze before the MAF which was clear and checked the MAF for any oily substances which may have come from the K & N filter, all seems ok, now what concerns me is the amount of soil like dirt stuck to the old filter, I traced the pipe back and basically I would like to identify a component, there is an air duct the left side of the radiator which goes into a black box which is mounted on the left hand side inner wing and has a ball shaped device mounted to the top of it the pipe then goes into the bottom of the air filter box, there is also an air pick up to the black box from the inner wing, now is this black box by any chance the intercooler or something similar, if I remove the lid screws will it be some kind of heat exchanger which may need cleaning out by the amount of dirt on the filter, it has obviously passed through this box.

 

[psmart]

Andy, the device you are describing is the hot air take up, which sucks in air from the wheel arch and from the engine compartment prior to it going into the air filter. Used to pre-heat the combustion air for more rapid engine warm up.

The bulb like device sitting on top is the Turbo Boost Pressure Valve Transducer vacuum reservoir.

Take a look here, http://www.detali.ru/cat/oem_mb1.asp?TP=1&F=163113&Cat=06H you can see your entire car and its break up.

The intercooler sits alongside the radiator. Trace the Air filter pipe to turbo, then the turbo pipe to radiator, this is the start of the intercooler, which exits in the right hand side with 2 transducers, 1 is the boost pressure temperature sensor, the other is the boost pressure sensor.

 

[Andy Wr]

Andy, the device you are describing is the hot air take up, which sucks in air from the wheel arch and from the engine compartment prior to it going into the air filter. Used to pre-heat the combustion air for more rapid engine warm up.

Is it worth taking it apart to clean it as like I said there was so much dirt in my air filter element it had obviously come through the "hot air take up", I had already checked out the russian web site but could not find the exact item to see an exploded diagram of it, I was curious to see if it was an heat exchanger of some description, either a finned coil or a baffle plate design. Do you know if the item is pressuried at all and would there be any benifits in stripping and cleaning it.

 

[psmart]

I made a slight slip up, hot air is taken from the exhaust manifold by a set of cracks/slits in the air filter, at the bottom back part of it, the black box is the air inlet, but it takes the air from the wheel arch (Im working on memory as I had it stripped down some months back) and another location, and its purpose seemed to be to act as a silencer. It is empty inside. If you are doing a fair bit of off road, sounds sensible that dirt may have got inside. From memory, its easy to dissassemble, just take off the concertina pipe between it and the airfilter and 3 (I think) screws, you dont need to take off the vacuum reservoir.

I have an adapter that fits onto the air filter (taking the concertina pipe off) which allows my ML to wade to engine depth in water as in standard form, you can only go to wheel arch depth.

 

[Andy Wr]

Thanks psmart, wheel arch depth is about as deep as I will go any way. One thing that I have noticed is with going off road regularly the plastic colour coded side sill covers are starting to bulge a bit at the end closest to the front door hinges as dirt and mud have got underneath them, I really must invest in a set of mud flaps and remove and clean the sill covers, one thing about owning a 4 x 4, I dont have to keep it as clean as a road going car, or should I say it is impossible to keep it as clean, my wife says I am as happy as a pig in mud......................yep!

 

[psmart]

Managed to get under the bonnet to adjust my xenons, so double confirmed what Ive said.

The pipe coming from the radiator section into the black box (air silencer) is the primary air scoop. The secondary air scoop is from the top of the wheel arch. The adapter I have blocks the primary air scoop (havent used it for a long time), giving wading depth to top of wheel arch level. Warm air is taken from slits at the back of the airfilter for rapid engine warming.There are 4 screws needed to take the lid off the black air silencer box.

Hope this is of more help.

 

[Andy Wr]

Thanks mate, I shall strip it next week for a clean out.

 

[Andy Wr]

Stripped the air silencer black box and it was clean so I am happy about that, whilst in the mood I removed the passenger side plastic sill cover and cleaned out all the mud which had accumulated behind it, think I maybe need to keep an eye on the sills as damp mud can accumulate and possibly be a future corrossion problem, I also refitted my recently repaired plastic engine guard which got damaged when my cross member got bent and twisted whilst off roading before christmas. Does any one steam clean there ML's annually just to remove the build up of crud etc.

 

[psmart]

Stripped the air silencer black box and it was clean so I am happy about that, whilst in the mood I removed the passenger side plastic sill cover and cleaned out all the mud which had accumulated behind it, think I maybe need to keep an eye on the sills as damp mud can accumulate and possibly be a future corrossion problem, I also refitted my recently repaired plastic engine guard which got damaged when my cross member got bent and twisted whilst off roading before christmas. Does any one steam clean there ML's annually just to remove the build up of crud etc.

I regularly jet wash all the car wheel arches, underpan, engine bay etc and I spray grease/wax oil as much as I can. I was suprised to learn there was a tad rust on the underpan and some on the drivers door (all to be sorted under warranty), but other than that, you need to be pro-active. Your in mud, Im in chemical and salt laden baths all winter, so either can do no good.

Never thought about steam cleaning, after all, as Sprint'N'Go pointed out, our cars are 4x4 off-roaders, so a bit of pressured water is all part of there design parameters so no harm comes from it.

 

[Andy Wr]

Are there any precautions that you take while jet washing the engine bay as mine is already quite muddy? I jet wash the wheel arches, inside the front bumper around the wheels where I can reach, the engine guards, diff, radiators etc just about everything I can reach.

I have noticed that some rust has been repaired on the rear passenger door but is starting to come through again, Is there a way to find out if any warranty paint work has been carried out to my particular vehicle.

 

[psmart]

No real precautions other than I always run the engine at full temperature, have the jet wash on a low pressure fine mist and avoid directly spraying the electronics/sensors. I thoroughly clean the Radiatior, Intercooler and Gearbox cooler several times a winter.

The ML's have a fault on the bumper design, a real rust catcher. Ive had to replace the horns once and even though I took precautions after installing a 2nd set of horns (greased the contacts etc), the 2nd set have almost gone. The metal brackets I dose time and again with spray grease because they get so caked up in crap and rust.

Wheel arches, again nothing special, but use a high pressure mist directed under the plastic from inside and out of the engine compartment. Shox have taken a beating though, rusty as the proverbial (replace this summer all being well).

Regarding rust, all work carried out by Mercedes should be on there computer, book it in for a rust warranty check (free).