m62tu/S62 Hot film air mass meter

[BreakMyWindow 1874]

So i've done a bit of reading up about these. How they can affect the cars performance if they are dirty or faulty. According to the people in the USA the s62 and the m62tu both share the same bosch Hot film air mass meter, the s62 has two. I removed the sensor out of my m62tu and found these part numbers : BOSCH F 00C 2G2 029

Does anyone know if this part was used on any other bosch meter equipped european vehcle?

[*Glenn* 854]

I'm not sure about other vehicles.. Petrojet in Auckland should be able to tell you Ph. (09)4481071

The air mass sensor can be checked on the car using a scanner and reading live data, what is the problem ? & why did you take it off ??.......and dont try cleaning it with anything

[BreakMyWindow 1874]

Thanks for the reply there Glenn. I had a wee chat to you the other day on the phone about my car regarding the valley pan replacement job.

The car is stalling occasionly when lightly tapping the gas pedal from idle at any temperature. It has been doing so before several months, and gradually geting worse, its now possible to trigger a stall with the following..

i.e idle at 400rpm, tap gas, revs go up to around 7 - 900rpm, revs then go below 400 and then stall. Some times it won't stall, it will drop down to about 200 and then catch its self, the revs in this situation go back up to 8 - 900 and then slowly go back down to idle. The car has been scanned and several faults came up.. cam posi. sensor bank 2, cam control bank 2, and something regarding the thermostat. To my understanding the HFAM may not bring up a fault as it is still working, but in my case, maybe not idelally. I am just waiting on a new cam posi. sensor, so if replacing that doesnt make an improvement i will lookin to doing the HFAM meter, and pre-cat oxy sensors as the car has done 230,000k's and i'm pretty sure these are original items.

The car just had a big job done on it (valley cover, inlet manifold gaskets, throttle body gaskets, crank vent valve replaced, valvle cover gaskets, timing profile gaskets, new waterpump and thermostat.) and im sure it wouldnt be a vacum leak causing the idling/stalling problems.

I'm wanting to get the car on a dyno and have the live data read, and also a few power runs, as i feel its a bit down on power when at around 4000rpm in 4th gear... nz roads are not really ideal for this kind of testing ;-) The idea is to see what improvements the new HFAM meter and pre-cat sensors make in a before and after test.

[*Glenn* 854]

If it has camshaft position sensor faults.... they will cause the problem you are having. And yes a faulty HFAM will not necessarilly show a fault code unless it stops working altogether

[kiwi535 538]

I beleive the E39 m5 guys also use some vw maf , i will post a link to some discussions tonite...cant quite recall the url for e 39 m5 forum

Edited December 10, 2008 by kiwi535

[BreakMyWindow 1874]

yeah I did some reading on that m5 forum. Apparently the Landrover Freelander TD4 (not sure on the year yet) uses the same sensor as my car, i could get one of those (if its cheaper and do need a new HFAM) remove the sensor from the intake pipe, and drop it in to my existing pipe.

The guy's in the USA have reported that using CRC Mass air fliow sensor cleaner on the HFAM in the m62tu with mixed results.. some cars have had no difference, where as others have had an improvement after cleaning (more power, improved idling, no stalling) This may be a placebo effect, so i'd be keen to do this on a dyno with before and after results.

[kiwi535 538]

be worth a try wouldnt it...cleaning i mean.could it make it worse?

[*Glenn* 854]

be worth a try wouldnt it...cleaning i mean.could it make it worse?

Personally .... I wouldnt. These can be damaged just by moving or knocking them....your call though

[BreakMyWindow 1874]

At this stage i'll replace the cam posi. sensor and go from there.

Thanks for your input guys.

[mr E34 11]

As Glenn said, be careful with those hot wire systems, when you turn off your car they normally put thru a quick burst of increased voltage to burn off any crap.

As for dyno before/after,waste of time/ money if you have faults, get everything addressed first....not sure if this is any help but in the latest TBMW mag they talk about the E39 M5 afm being a weak point, faulty units cause big pwr drop offs...................these two(2x units on M5) small plastic tubes are the key to the M5 & with new ones it's like having another 100hp!

[10hove 0]

As Glenn said, be careful with those hot wire systems, when you turn off your car they normally put thru a quick burst of increased voltage to burn off any crap.

As for dyno before/after,waste of time/ money if you have faults, get everything addressed first....not sure if this is any help but in the latest TBMW mag they talk about the E39 M5 afm being a weak point, faulty units cause big pwr drop offs...................these two(2x units on M5) small plastic tubes are the key to the M5 & with new ones it's like having another 100hp!

Sounds like the daignosis is spot on we have replaced dozens of these, usually with an immediate improvement not only at idle and low speed but also performance an around a 10% increase in fuel economy.

Up until now we have always used genuine replacement at around $900. we do have an insert avalible now that will fit certain meter housings though.

Feel free to give me a call

Regards

Alex

http://www.carspot.co.nz

Ph 0800 924 817

[BreakMyWindow 1874]

Well, I got itchy feet today so i thought bugger it, i'll clean the HFAM. I went to repco in onehunga and picked up a can of crc mass airflow sensor for $23. I removed the insert from the HFAM pipe, sprayed the resistor section, and the lower sensors with solvent as per the instructions. The cleaner dissolved pretty much instantly, i let it dry thouroughly beofore I re-installed. After my test drive.. Although the idle problem wasn't sorted, the car felt a bit more alive below 4000 rpm. No harm done. Cam sensor replacement next.