jasonmcx30

Thanks for the detailed description on the cleaning. Totally fixed my rough idle for now.

Much thanks.

fookoo303

thanks for this writeup. 170k on the clock and ive never done this, so mine is probably filthy.

fookoo303

I took the throttle body out and i dont see an o-ring in between the tb and the manifold. Can someone verify if there is an 0-ring or gasket? or maybe its just silicon?

Glyn M Ruck

Here is the TB & piping



See here for other inlet diagrams on C240

https://mbworld.org/forums/c-class-w...ugged-maf.html

fookoo303

dang there is an o ring.... I looked at mine and saw silicon being used so I had some hondabond laying around and used it. I even asked the dealer if there was one and they said they werent sure and that they also use silicon in their engine. Glyn do you think i might have issues down the road with the silicon?

Glyn M Ruck

Hondabond is a good product & at least is not acetic acid curing so it wont corrode the alloy. Long term I would fit the correct O ring.

fookoo303

ok hopefully it will last me until the end of winter. Ill change it out once it gets warmer out. thanks for the input glyn

fookoo303

Hey everyone, Can anyone confirm if the o-ring (number 89) found in the diagram that glyn has posted is part number 305-997-03-45? Thanks in advance

Carsy

I am new to MAF,s & would appreciate some information on my diesel OM 646

Does cleaning the Maf on a regular basis prolong their life & why. ?.

On my last inspection ie 30,000 km the maf was covered with oil from the breather which enters a little downstream. Would this have negative effecton its longevity ?

The engine is running perfectly.

Thanking you,

John.

Glyn M Ruck

John - If the engine is running normally with no sign of over/under fueling - smoke, flat spot etc. I would leave the MAF well alone. Diesel MAFs can tolerate plenty of oil. If you ever do experience bad running then unplug the MAF. This forces the engine onto a default MAP. If it runs better unplugged it's time for MAF cleaning or replacement if cleaning is unsuccessful.

Carsy

Thanks Glyn. Printed & filed.

Sincity

Tks for the DIY.

tiderfish

I know this is an old thread. But can I just clean the MAF with the CRC cleaner while the engine is on? On my engine, (M271) I can see the MAF when I remove the air filter.

Can I just shoot the MAF cleaner inside the intake while the engine is running, or should I just leave the engine off, and let the car sit after I clean it so it can evaporate?

RedGray

See:


CRC Mass Air Flow (MAF) Sensor Cleaner Instructional Video
CRCAuto
Published on Oct 29, 2014

Most fuel-injected vehicles are equipped with a mass air flow sensor, or ---MAF--- sensor to measure the amount and density of air entering the engine. This is information the computer uses to determine how much fuel to inject into the engine for combustion as air enters the cylinders. Ignition timing is also affected. The MAF sensor wire gets dirty with accumulated debris, oil, air filter fibers, dust and pollen. This can cause inaccurate readings and negatively affect the air to fuel ratio.

Signs of a dirty MAF sensor could be a check engine light. You may experience a loss of power, stalling, rough idle. Your engine may also be running rich and producing excess emissions. The original Mass Air Flow Sensor Cleaner from CRC Industries is a unique precision cleaner specifically developed to clean sensitive components in MAF sensors without damaging or degrading plastic or painted surfaces.

Use CRC Mass Air Flow Sensor Cleaner with the engine off. Always wear gloves and eye protection, and insert the straw into the nozzle before an application. Remove the air filter to gain access to the MAF sensor located between the air box and the throttle body. It is recommended that you remove the sensor for best cleaning, but it's not absolutely necessary. Place a towel under the MAF to catch any run-off. Using the straw attachment, apply 10 to 15 short bursts of CRC Mass Air Flow Sensor Cleaner to the hotwire or the hot plate.

Be careful not to let the straw, or anything else come in contact with hotwire. Keep the end of the straw 4 to 5 inches from the hotwire. Be sure to spray all sides of the MAF sensor and clean all wires and connectors.

Reassemble the MAF and allow to dry thoroughly before restarting the engine.
Often, technicians will try to use throttle body, carburetor, or brake parts cleaners to clean sensitive MAF sensor components. However, these aggressive cleaners can be damaging to plastic, which most MAF sensors are housed in today. If the plastic degrades or warps, the MAF hotwire can shift and malfunction, resulting in expensive repairs.

Use only the original Mass Air Flow Sensor Cleaner from CRC Industries to safely clean the delicate components of the sensor. Regular use will restore horsepower, reduce rough idle, decrease hesitation and pinging and improve gas mileage.

Dnasty

Sorry to dig up this old thread but it’s still relevant for me. I just did a cleaning on these parts. I didn’t remove the throttle body but cleaned in the area as much as I could. I was wondering what symptoms the car has when these parts are dirty. I’ve been trying to figure out an occasional hard start ( that happens when the car is warm) and also some surges when braking. I thought it might be a sticking throttle body plate because when the car is struggling to start, if I tap the accelerator it turns right over. After my first clean this problem still persists although it didn’t resurface for a few days after cleaning. Wondering if I should try a full throttle body clean or if this is related to something else.