Mass Air Flow Sensor cleaning

[Wldeyefoto]

The S62 motor in our Z8s uses 2 mass air flow sensors (MAFS) to measure air flow and mass in the intake tract and the engine's control computer uses this information to determine the appropriate amount of fuel to inject into the cylinders. If these MAFS become contaminated with pollen, dust, or soot, their readings will be adversely affected and the engine will tend to run too rich. They can also be contaminated with oil from reusable aftermarket air filters leading to rough running and a loss of power output from the engine. Up until now, the only practical solution was to replace the MAFS with new ones, a very expensive proposition. CRC has recently released a new product called Mass Air Flow Sensor Cleaner which makes cleaning MAFS a viable option. Just a quick spray of the sensor and the contamination is gone. Now, every time you change your air filter, no matter what type you're using, you can clean the MAFS at the same time and insure that your whole intake system is working properly. Check it out at www.crcindustries.com. CRC products are readily available at most auto supply stores. Grease Monkey

[pandaman]

[Michael]

Does anyone have a schematic of the location of these two sensors?

[Wldeyefoto]

The MAFS are located in the air flow meter housings. These are the solid plastic cylinders right next to the air cleaner boxes and they have a wiring harness attached to them. Those wires are hooked to the MAFS which are bolted into the air flow meter housings. When cleaning the MAFS, be very careful with them as they are quite delicate. In particular, do not touch the sensor area with your fingers.Grease Monkey

[Michael]

[Z8mania]

If you tell your dealer your car feels like its down on power, they will check, and replace, the MAFS for you- just be sure that you are within the maintenance period or have the dealers good graces. 2 MAFS can cost about $700! The process of opening up the airbox/ getting to the MAFS is not too bad, but if you are nervous, you can just go to the dealer. I think every 3 years one should get this checked.

[Z8mania]

each MAFS will not cost you $350- but the way it comes from BMW, its the MAFS + hose and housing and then installation, the whole thing will cost this much. Its very expensive for what it is, and BMW is not the only make which has the issue of MAFS getting dirty over time.

[Orcatek]

Over on the M5Board they have found that VW MAF fit and work and are very cheap. Read about it and decide if it is right for you.

[harvey2]

Is it possible to spray this cleaner in effectively without disassembly and removal of the MAF? I'm wondering if removal of the air filter and spraying into the air inlet with the car operating might not direct enough spray to be useful.

[Gobosh]

I just recently had both MAFs replaced on my 2000 M-5. The dealer said that MAFs were covered to something like 80K miles under federal regulation because they are part of the pollution control system. My car had been running sluggishly....but it felt like new after the MAFs were replaced.

[Z8mania]

I believe people found with the VW MAFS that they are more sensitive to dirt and the benefit is quickly canceled out by the need to replace much more frequently. MAFS are just a "hidden" PITA in all the modern engines.

[Wldeyefoto]

This stuff is flammable so spraying it into an active intake tract would not be a good idea. The correct procedure is to either remove the MAFS from its housing and spray it with the CRC cleaner or remove the entire housing from the intake tract and clean the sensor inside it. Be sure to remove the wiring harness before spraying any of the parts. Then just allow the cleaner to completely evaporate and reassemble.Grease Monkey

[Wldeyefoto]

This is great information. MAFS are the most common reason for poor engine performance over time and if your dealer will replace them for free, I would certainly take advantage of that offer. For some of us, dealers are an unheard of luxury (nearest one to me is 500 miles) so the ability to clean the MAFS is a major benefit.Grease Monkey