Marcus Larsson

Hi.

I have a e500 2005 with m113 v8. Done 19800 km. Need some help here pinpointing a problem.

Out of nowhere i got code p0102 suggesting something wrong with the maf. The car idels fine, and runs fine in mid to higer rpm. When starting from a stopp the car feels slugish from time to time and i have to push the throttle harder to get a reaction at low rpm.

i have removed and clean the intake and the maf. No change. Still slugish at low rpm. Everything else is fine.

i have let the car idel without a maf. It idels "normal" without the maf but feels more slugish when reving.

the volts in the maf connector is within specs.

if i clear the codes or remove the battery the car runs pretty much fine. When i restart the car the cel comes back.

does this suggest a bad maf or could it be something else?

Marcus Larsson

Here is a freeze frame from torqe if that helps anything. While driving highway the car seems fine. Pulls normal. But when creeping and going from a stop the car judders

Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 33,333 %
Engine Coolant Temperature = 9 °C
Fuel Trim Bank 1 Short Term = 0 %
Fuel Trim Bank 1 Long Term = 0 %
Fuel Trim Bank 2 Short Term = 0 %
Fuel Trim Bank 2 Long Term = 0 %
Intake Manifold Pressure = 4,786 psi
Engine RPM = 1 200 rpm
Speed (OBD) = 0 km/h
Timing Advance = −9 °
Intake Air Temperature = 9 °C
Mass Air Flow Rate = 68 g/s
Throttle Position(Manifold) = 7,843 %
Air Status = 0 byte

hayseed

iTrader: (2)

clear codes and unplug the MAF ,,, start the car and drive it for a bit and see if the same code(s) appear -- if they do its a good chance the MAF is bad

Marcus Larsson

Thank you. I get the same code + p0112 intake air temp circuit low input without the maf. The car idels the same without maf but is more sluggish when driving than with maf.

i replaced valve cover gaskets about 2 weeks ago. The car have been fine til now. I been driving for avout two days. Its gettiga worse now at low revs. No missfires. Smells like its running rich from time to time. Revs are normal when driving and ideling, just that its being chocked from time to time with engien shake.

hayseed

iTrader: (2)

I am guessing but the prior work done on calve cover gaskets could be suspect... possible a loose connection wire or bad coil pack,,, engine shake could be a cylinder missing

Marcus Larsson

Yes, im going to remove and redo the valve cover gaskets just to be sure. One of the breather hoses is replaced, the others seem fine. No leaks when testing with starter gas.

i did remove the maf again for cleaning, noticed that i had lots of k&n oil on the maf and in the maf body. I must have made a mess somewhere when i reoild the filters. Cleaned the filter box and maf body twice, tried both with k&n and oem filters. No changed other than that i got a new code, p0101 insted of p0102. Could the k&n oil have damage the maf?

Im thinking, if it would be a leak in valve covers, breather covers, should that not affect all of the rev range? If going fast or full throttle the car pulls hard and feels normal, it only chocks when going slow, like when stopping or pulling away slowly. The car also shifts funny when going slow, but i think its compensating so it wont cut out.

cmriv

your baffles on your valve covers are probably clogged. Do you have any adaptation values? Those will instantly tell you what the issue is.

Marcus Larsson

Thank you for the tip. I will check that today

mtrevelino

Just my opinion, but I would get rid of the K&N filters. Your troubles started after you reoiled the filters. With today's vehicles having maf's and everything else, it does not take much to destroy these items. That is one reason they sell special maf cleaner. If you used carburetor cleaner it would destroy the maf.
Again, my opinion, I think K&N filters are good if they are on a vehicle with a carburetor and not in any type of enclosed housing.
Mike T.

Marcus Larsson

Yes, its a possible. Did valve cover gasket and service at the same time. About 2 weeks later the problem started. The maf was coverd in oil. I cleaned the maf with electronic cleaner a low psi air.

i did not do the breathers on top of the valve cover. They are leaking oil, no vacum that i know of. Going to redo valve covers and do the breathers in waiting of the new maf or would it just be waste of time?

Marcus Larsson

Ive done some more test with a mulitmeter when backprobing.

At wire 3 and 2 i get 11.45 volts with engien off ang ing. On. With engien on i get around 14.5 but it barely change when i rev the engien, moves around 14.3-14.8.

At wire 3 and 4 4.95 with ingnition on and with engien on and reving. 4.95 is constant no matter what.

what do you guys make of this?

cmriv

Hot film MAF sensor signal input= ignition on/engine at idle
(ECT at 70 degrees celcius)

0.9-1.1 VDC

1.3-1.7 VDC
voltage raises with increasing rpm


If you want to check to make sure MAF has a good ground, disconnect MAF sensor connector, turn ignition on and your reading should be 4.7-5.2 V...


and what wiring diagram are you referring too? Because pin #2 is a z-splice to your cam hall sensor.......

Marcus Larsson

I cant get such low values on any cable. If i hold the voltmeter to ground cable and any other cable i can get the value presented in my las post. How do i check the signalwire? Just to make sure i do nothing wrong.

i followed this post

http://www.benzworld.org/forums/w163-m-class/1401925-maf-problem-poor-accel-cel-wiring-2.html#/topics/1401925?page=1

hayseed

iTrader: (2)

here is a cheap replacement - the K&N oil has a bad habit of destroying MAF;s

http://www.autopartswarehouse.com/sh...nsor-2005.html

cmriv

thats a wiring example for a 163. same engine yes but pin designation isn't the same. wire colors are the same to but in a different order on the connectors for the maf and going to the ME.