Mjuu

Hi everyone,

My '01 ML wont readily shift into the next gear (eg 2nd) after I 'floor it' from a standing start....but everything is fine in normal driving use. https://mbworld.org/forums/images/smilies/werd.gif

The problem only surfaces under full throttle and each expected gear change at the upper rpm point just doesn't happen unless you back off on the throttle to reduce the Rpm - and of course when you've just pulled out into highway traffic this isn't what you want to have happen.
Any clues/suggestions what to check before I contact local (expensive ) MB dealer who will probably try his luck at my expense?

Thanks in advance to anyone who can help.

Mjuu

Addendum to my last post....

According to my local MB dealer , its the MAF sensor causing a mixture lean out (under load) and thereby preventing the engine from reaching the upper Rpm gear change point. You can feel the lack of power when you reach 3000 rpm and the engine really struggles to get to 3500 and beyond.
Any comments anybody?

If this is true, does anybody know if these MAF sensors which proliferate on ebay are any good as replacements? I've seen one at http://cgi.ebay.com/ebaymotors/MASS-...mZ160176416618

Thanks!

ohlord

you read your codes?Did the dealer scan for codes?Is the check engine light on?
Let's start there.
ohlord

ohlord

a maf on ebay!
Read my posts about the subject on the w210 forum or on benzworld.org w210 section.Buy the maf unit at one of the real online supply houses. www.germanstar.net has inserts for $127,and the whole unit at around 200 approx.Autohausaz.com has them also.Unless the housing has cracked ,the insert is a fun diy and works.
Always follow the proper diagnostic tree to get the solution.
Far to many people throw in a maf because they hear it solved this or that and they end up solving nothing.
Read your codes.........1996 or newer you are obd2 compliant so get the scanner at harborfreighttools online or at one near you if it is in town.The 94169 is on sale for $39 at times or 50 bucks at others.CEL is on read the codes,post them in the forum or feel free to shout out.
Buying ebay is a gamble,read my post from several weeks ago on benzworld about the chinese clones that are sold by the container load for 17 bucks and resold on ebay for 100 and up,and fail within days or less in most cases and fail so badly they affect other items in the cars systems.

CEL on?read the codes,post them,find the solution.
ohlord
"GOT CODES?"

Mjuu

Hi and many thanks for the support.
Just so you know my whereabouts - its Oz and that tool place you mentioned isn't over here ( yet?)
As for the codes, the stealership didn't provide them - this is what I was given/told - "Found air flow meter and stop lamp switch faulty"
Then they quoted the prices...
Can I 'force' them to provide them or should I try to source that gizmo you mentioned thru web? As far as I know, the brakelights arn't flicking on/off as would be expected with a dicky switch...I can test it easily though. I guess its near the brake pedal so tomorrow I'll have a closer look with a multimeter.

Thanks for the steerage on eBay - will get MAF at germanstar (once I know thats the problem)

Btw, what is CEL ?

As for warning lights - well, for the past coupla' months I've only had the SRS indicator light up and then go off - usually going out within a few minutes of driving off; specifically it has lit up only half a dozen times at seemingly random times, but just yesterday (after I disconnected the battery for the 1st time), the BAS/ES lamp came on and then went out only after I had driven about a mile down the road ??

Does that make more sense or throw any light ?
Thanks again,
Cheers.
PS: Just a thought - I had to pay $60 for the diagnostic 'quote' so doesn't that give me the right to insist on being provided with the codes?

Mr Cheeks

ohlord is right invest in an OBDII scanner code reader it is a usefull tool for Check Engine Light codes. CEL light only comes on with Engine emission and ignition problems. My scanner came up with the PO170 and PO173 code when i diagnosed my 320 so i bought the MAF sensor from OEMPARTS DIRECT as they where prepared to ship to the UK but first try cleaning the sensor with CRC contact cleaner or something similar. Do not buy an insert from Ebay unless you are convinced the seller is selling the genuine item or has been recommended buy others but it is still a risk.

Mjuu

To all concerned so far - I just got this from our local Boach distributor ...the plot thickens.

..."We would like to advise:
This sensor cannot be purchased separately, it is part of the complete
assembly that is calibrated when assembled.

The Mass Air Flow Sensor when manufactured is fitted with the sensor F00C
2G2 02S which is uncalibrated or aligned. Laser light is used to align the
sensor with the airflow then the screws are locked. Once this is done the
calibration process is done with a measured airflow at idle and wide open
throttle. The MAF is only available as a calibrated assembly.

Please do not hesitate to contact us again if we can be of further
assistance."

Customer Service Representative
Robert Bosch (Australia) Pty Ltd

Mr Cheeks

Absolute rubbish many alot of members have bought inserts from Germanstar and have had no compliants it is easily removed with a security torx screw obtainable at any DIY store. Although it is worth cleaning the MAF Sensor to see if you have any improvement before buying a new one. If you dont have the CEL light showing the problem could be elsewhere.

wadigo

I have a similar problem, I get po170 fuel trim bank 1. I changed the MAF (purchased at ebays), and it worked ok for a while. Now it hesitate and turns off when in idle. Sometimes I have to give it gas to start the truck.While at speed it would try to shut off ...

I cleaned the MAF. But I still get the same problems.

Mr Cheeks

check your air intake system for leaks or cracks in the hoses Beware of MAFS bought on ebay some are not genuine Bosch MAFs

wadigo

Is it difficult to replace the hoses?

Mr Cheeks

no hoses are not hard to replace they are usually attached by jubilee clips