waveflux

Yea, because of the help I got on the forum. I was headed in the wrong direction with the vaccum system. But....we all know this is "whack a mole' fix one thing over here and another pops up over there.

waveflux

Thank God it was only a $29 lesson, and not a $2900 one.

Stan.Shaw@Excell.Net

You could try to sell the K&N filter to someone without a MAF...

I still have the one I used in my 80 Euro S available. Some might say the K&N could lead to extra wear in the motor (due to larger particles getting in), but when my motor was torn down after many years of K&N use, it looked fine. YMMV of course.

Mrmerlin

also to note the KnN filter doesnt seem to fit the filter housing as well as the factory part does and thus its possible for dirt to get in at the back of the housing.
Now couple that with loose hold down rubbers and it wont be long before you have more contaminates into the engine intake

waveflux

It was too good to be true....MAF gave up the ghost today. Peering out of window for UPS truck next couple of days.

Charley B

I checked with Snopes.com regarding K&N filter vs Porsche 928.

They say it's just an old wives tail buttressed by anecdotal evidence but never proven one way or the other.

deutschmick

Good to know. I'm still waiting for MAF problems from the K&N I've had in the GT for the last 10 years!

morganabowen

The problem with my MAF was not related to K&N, since I was running with the OEM Good luck with the new MAF

waveflux

Could be mine just needed replacing. Timing is bad for K&N..cuz I'm banishing them.

no doubt

No problem with my K&N's in any of my cars.

John Speake

K&Ns are OK MAF-wise until they are over-oiled when cleaning and re-oiling. People tend to overdo the oil part.

Using CRC might remove enough of the oil if you catch it early, beofre the MAFs burn off cycle burns some of the excess oil into a hard deposit on the wire. The burn off was only designed to cope with very light oil vapours that settle on the wire.

For these reasons I don't reecommend the K&N generally.

M. Requin

My experience is not as great as others here, but I have had excellent results with K&N over the years, especially on motorcycles (as a bike dealer I sold and installed tons of them). When I bought my 86.5 it had a K&N, so I cleaned it, oiled it, and it has been fine since. But mind John's words - overoiling is almost always the culprit, and I have seen a lot of that on bikes. And the fit problem mentioned above is somewhat true- I think you just have to be VERY careful that it is completely seated before you close it up.

One more thing, I actually need the K&N. I live a mile or so down a very dusty gravel road, and replacing paper element air filters several times a year (at least) would get to be pretty expensive.

VehiGAZ

Excellent points, John.

I had no problems with a K&N in my old Prelude for 4-5 years, then a dead MAF 4-5 months after putting a K&N in my VehiCROSS. I have had MAF problems in my 928 without a K&N, but will never try one.

Let's agree that K&N oil seems to affect some MAFs more than others...

VehiGAZ

Ok, that said, the dreaded "limp-home mode" mentioned at the start of this thread is probably the dreaded "4-cylinder mode," which is different from the true "limp-home mode". You can confirm that it is truly 4-cylinder mode by checking for a green or red LED on inside the ignition protection "relay" thingy next to the LH in the passenger side footwell area.

I have had lots of intermittent issues with 4-cylinder mode. A rebuilt MAF cured it once last year, but it came back this year. Monkeying around with the wires & connectors on the two exhaust temp sensors seemed to fix it the second time. If the sensors lose connection and/or signal, the ignition monitor relay throws the engine into 4-cyl mode - crippling the car to let you know that the sensor is out. What sweethearts those Porsche engineers can be!

You can buy an ignition monitoring circuit bypass relay to keep in the glovebox in case the demon appears at a particularly inopportune time.

Good luck chasing this ghost in the machine...

Jim bailey - 928 International

Really does not sound like a MAF problem at all. My vote is the ignition monitoring relay cutting of 4 cylinders. As mentioned the K and N gets blamed for failures with no PROOF that it has any negative impact on the MAF. The problems with the head temp sensors are typically intermittent ....shutting off and restarting the car often resets it. It is also possible that you have a bad corroded coil wire and the car really is protecting itself by shutting down 4 cylinders that are misfiring.