Bosch MAS/MAF Only Lasted 9 Months

[Aletank]

I replaced my Bosch MAS 9 months back from airmassmeters.com with a genuine Bosch.
My symptoms were - Jumping into gear on 1st start up from cold, drive or reverse gear.I had just that for a while before I started to get the loss of power etc and would be fine after a restart.
I fitted the new Bosch and what a transformation ! everything was sorted !
I've started recently getting the jumping into gear when cold on the 1st start up again after only 9 months/5000 miles.
I've just sent airmassmeters.com a email and here's their reply

Bosch give a 12 months warranty, so that is within this.The part will have to go back to Bosch and they will check the part out and if faulty we will refund you.
We would need all of the vehicle details chassis no and reg etc also mileage used.
To keep the car on the road you would have to purchase another part from us if you wish or if you still have the old one that could be refitted until Bosch have checked the part out.
Please make sure that you are confident that the part is at fault before you return it.

I have my original MAS to use as a temporary but I'm not 100% confident it is the MAS.
If it is the MAS - why has it only lasted this long ?
What do you think i should do ? not long left on the warranty ! so i can't really leave it much longer to see if the loss of power symptom kicks in.
Thanks for any advice

 

[Dryce]

If it is the MAS - why has it only lasted this long ?

It could be that the MAF itself is OK but that it's being contaminated?

Any signs of oil/dirt on the old one?

 

[grober]

The thing that usually kills MAFS is contamination with oil film. This can arise from the use of aftermarket "oiled "filters like K and M or if the camcover breather which connects to the air inlet is blowing out a lot of oil vapour? You could try cleaning it up carefully with suitable cleaning fluid- a few " how too's" on here about this.

 

[Aletank]

It could be that the MAF itself is OK but that it's being contaminated?

Any signs of oil/dirt on the old one?

There's no sign of oil/dirt etc When the original started playing up I would remove it and clean with contact spray and it would be fine again for a while but there was no visible dirt.
I have a standard OEM Air Filter which is always clean BUT my Cam Cover Breather Pipe always has a film of oil on the Cam Cover.
Doesn't the flow of air go , Air filter - MAS - Breather Pipe ? If so doesn't that mean the oil contamination is going away from the MAS - Or could it back track ?
If the oil is coming from the Cam Cover Breather Pipe - Would Bosch test the MAS and deem it faulty and replace ?
All importantly how could i stop the Cam Cover Breather Pipe weeping oil ?
Thanks Again For The Replies and Ideas !!

 

[Aletank]

Here's some pictures of my Cam cover Breather Pipe - Is this normal or do you think this could be causing oil contamination on my MAS ? (click the pics to enlarge)

 

[grober]

I would have a look for oil contamination in the air intake between the breather pipe and the MAFF to see if the oil vapour is backtracking. Try disconnecting the breather pipe- block off the pipe spigot that leads to the inlet temporarily -start up the engine and see if the engine is smoking excessive oil vapour from the crankcase out the camcover vent.

 

[Aletank]

I would have a look for oil contamination in the air intake between the breather pipe and the MAFF to see if the oil vapour is backtracking. Try disconnecting the breather pipe- block off the pipe spigot that leads to the inlet temporarily -start up the engine and see if the engine is smoking excessive oil vapour from the crankcase out the camcover vent.

I've just took the air duct pipe off just after the MAS and run my finger around the edge of the MAS housing and all feels dry.
I then took the Oil Breather Pipe of the Air duct ,started the engine then covered the end with my thumb. There was no smoking of oil vapour but could feel the vaccuum when i tried to remove my thumb. Bits of oil was trying to ouze out of the Camcover Vent/Breather Pipe connection.

 

[BlackC55]

Is the air filter clean?

 

[Adam230K]

Can i just ask (I dont mean to high-jack the thread), but if this breather is releasing oil vapour, what does that mean?

I'm intrigued

 

[w124coupe]

As to vapour going "backwards" the answer is yes. The action of the valves and pistons on the column of air in the intake causes oscillation back and forth - its not just a steady flow into the engine.

Oil contamination insulates the MAF element so it will under-read the airflow AND react slower when you suddenly want to accelerate.

Is this a high mileage car?

When was oil last changed and is a type and viscosity suitable for the cars mileage being used?

 

[Aletank]

The air filter is clean
Mileage of the car is 91k
Oil last changed at 85k on 31/7/08 Using Mobil 1 Fully Synthetic (Costco)
So the MAF has had about 5k miles use

Thanks Again For The Replies

 

[lynall]

I suppose it depends on how much a new one is and what damge will be done and driving enjoyment lost whilst struggling along, i think i would get a new one send the faulty one back and see what happens, if you have to pay for it, so be it then e bay it or stick on classifieds and sell it, you wont get all your money back but some is better than none.

Dont forget it will sell well as this isnt an unusual fault with any modern car nowadays.



Lynall