1998 s70 Mass air flow sensor keeps going bad

christylee26xs · Post by **christylee26xs** » 05 May 2014, 21:06

I recently changed the mass air flow sensor for the second time in less then one year. The first one I replaced lasted anout 5 months and the last one lasted about one month. There was one vacuum leak that I know of which I fixed. Why are the MAF sensors going out so quick? The car only runs(right now) if the sensor is unplugged and it looses power sporadically. When the MAF was brand new it ran perfact.

AVIP · Post by **AVIP** » 05 May 2014, 21:13

Do you have a regular filter or a K and N filter? Over oiling can lead to premature failure.

Also what brand did you buy? OEM bosch is amazing. Lasts forever. Have you tried cleaning with electrical or maf cleaner?

Could also be an exhaust problem.

Post by **erikv11** » 06 May 2014, 01:34

+1 to everything AVIP said.

Bosch only on this part. The non-Bosch MAFs can even be useless right out of the box.

Post by **alschnertz** » 06 May 2014, 04:17

On my '95 854T, the factory MAF lasted about 17 years and 209,000 miles.

I replaced it with a new Bosch MAF from a major supplier which lasted 1 year and 14,000 miles. When that died, the place I bought it from offered me a new Bosch replacement at no charge. I thought that was kind of them.

That Bosch replacement only lasted 2 months and 3,300 miles before it died. I returned it for a refund and purchased another Bosch MAF from a different supplier on a different coast.

It's now been 4 months and 5,000 miles later and all is well, but I suppose time will tell.
My suspicion is that there was a bad batch of MAFs from Bosch and the first supplier got stuck with a couple.

Post by **erikv11** » 06 May 2014, 07:35

Wow, good to know, alas!

Or similarly, I wonder if they were counterfeits at the first place. In that case you can't even trust major suppliers ... what to do.

And as someone pointed out in another thread today, the 99+ cars require a Denso MAF, this "Bosch-only" claim is also only for 98 and earlier.

Post by **cn90** » 06 May 2014, 07:46

Yeah,

I wonder about counterfeit stuff too.
Bosch MAF is usually very good.

PS: I just googled "bosch maf counterfeit"...interesting readings.

Post by **cn90** » 06 May 2014, 08:00

Re ? counterfeit issues, I saw this post:
http://www.alfaowner.com/Forum/alfa-159 ... -mafs.html

...cona says:
Bosch original parts should come with a hologram and code on a Bosch package. Then you can check the code on their web site to confirm the part is genuine. My glow plugs came in such package and I believe it is the same with many other parts. I ordered them directly from Bosch distributor.

For Volvo Bosch MAF, is there a hologram and code to check?

Post by **alschnertz** » 06 May 2014, 08:09

cn90 wrote:For Volvo Bosch MAF, is there a hologram and code to check?

I remember a fancy seal across the opening of the box, but don't remember if there was a hologram.
I should still have the box from the last one and will try to remember and check tonight.
That's an interesting scenario.

christylee26xs · Post by **christylee26xs** » 06 May 2014, 08:36

The MAF i bought is a generic brand, wssnt saving money after all. I did clean this one with some brake cleaner and so far so good. Car is running good right now, i guess i`ll see how long it lasts. Definatelywill be replacing it with a bosch.

Post by **alschnertz** » 07 May 2014, 03:48

Yes there is a website for verification and the seal does have a series of letters and numbers to enter on the website.
I did it with the numbers on my latest MAF seal and it came back as
"Congratulations! The Code you entered is correct. The quality verification is carried out in combination with the genuine Bosch Hologram "

So I guess that means that at least the seal is genuine since I could remove the MAF from the box without damaging the seal. Well, at least they're making some effort to reign in counterfeit parts.