Well, we're in limp mode and..(for the techies) - The Unofficial BMW M5 Messageboard (m5board.com)

cvp911t · 14th October 2004, 05:03

symptoms:
-Earlier, the car would hesitate when motor was cold (and got better when warmed up)
-Very rough idle (the car literall shakes)
-Now, loss of power throughout the powerband, at all speeds, at any engine temp

Had a buddy Pull the following codes:

Table 18:
B8 - intake camshaft vanos position control (cyl 1-4)

And basically misfire codes on cyl 1-4, and cyl 8. Also got air fuel adapation (error AF) for cyl 5-8 - which we suspect is a cascade effect on the main error B8.

So....I'm thinking if this is the camshaft position sensor? Any of you gotten this error before? Thanks in advance for any help.

Lance

stanm5 · 14th October 2004, 05:26

Quote:

Originally Posted by cvp911t

symptoms:
-Earlier, the car would hesitate when motor was cold (and got better when warmed up)
-Very rough idle (the car literall shakes)
-Now, loss of power throughout the powerband, at all speeds, at any engine temp

Had a buddy Pull the following codes:

Table 18:
B8 - intake camshaft vanos position control (cyl 1-4)

And basically misfire codes on cyl 1-4, and cyl 8. Also got air fuel adapation (error AF) for cyl 5-8 - which we suspect is a cascade effect on the main error B8.

So....I'm thinking if this is the camshaft position sensor? Any of you gotten this error before? Thanks in advance for any help.

Lance

It's most likely the Cam Position Sensor and possibly your MAF's.
Bring it to the dealer and have them pull the stored codes.
Good luck.
Cheers,

BlueBomber · 14th October 2004, 07:29

Quote:

Originally Posted by stanm5

It's most likely the Cam Position Sensor and possibly your MAF's.
Bring it to the dealer and have them pull the stored codes.
Good luck.
Cheers,

As stanm5 has stated, it's probably a combination of the intake CPS and MAFS. I would start with swapping out the intake CPS. Once that's done, you'll likely notice a significant change in performance.

Since you have a 2000 M5, you'll probably have the older version of the MAFS which seem to fail earlier than normal. Thus, you'll have to end up swapping them out as well.

Ahmed · 14th October 2004, 10:42

had the same problems as you, replaced my intake can sensor, and new set of MAF's... the car runs great!

ilundber · 14th October 2004, 21:43

I have just had the same problem.
First time it was the magnetic valve for the vanos. An o-ring was busted. You can see if that is the case by checking if your air filters are being filled with oil coming from the plenum. The problem does not show up on the test but there is a servcie bulletine for it.
After that was fixed, a camshaft sensor stopped working (two weeks after and fixed today). The problem symptoms resemble the one with the magnetic valve, but is much less obvious.
So, check for oil in the air filters. If they are clean check the MAFs. If they are clean (I washed mine but got no effect) I'd say you have a camshaft sensor problem.

alibo70 · 14th October 2004, 23:58

Mine pulls the exact same codes. Putting new MAFS in this weekend.

cvp911t · 15th October 2004, 00:06

That's a new one - so your MAFS caused the cam position sensor error too? Thanks for all the replies...

alibo70 · 15th October 2004, 01:05

Its possible, but i'm leaning toward the MAFS. Earlier posts on the forum suggest that when Cam Sensor goes out the car just runs down right terrible. I really hope that of the two one of them is our problem. I can honestly say so far Beast ownership has been a nightmare. I mean MAFS are not exactly cheap. Just wondering does anybody know specifically what was updated on them after 2000.

alibo70 · 15th October 2004, 01:07

Oh yeah just remembered, cleaning them had no effect on them. Have tried it twice. But I guess it doesn't hurt. I like what somebody posted earlier "a group buy on them"

LSU1981 · 15th October 2004, 01:27

Try disconnecting the MAFs, then start the car. If the rough running goes away then 1 or both of the MAFs are bad. Reconnect one at a time to determine the bad side.

This will throw some more codes but ....

And it doesn't hurt the car, it goes to a default setting for A/F ratios, etc. --- just don't run it hard.

I don't have knowledge of MAF changes other than the change from 6pt torx security screws to a 5pt in 2003.

Mike

Quote:

Originally Posted by alibo70

Its possible, but i'm leaning toward the MAFS. Earlier posts on the forum suggest that when Cam Sensor goes out the car just runs down right terrible. I really hope that of the two one of them is our problem. I can honestly say so far Beast ownership has been a nightmare. I mean MAFS are not exactly cheap. Just wondering does anybody know specifically what was updated on them after 2000.