Results 1 to 9 of 9

Thread: Weirdest CEL Ever! Maybe Not?

  1. #1
    Join Date
    Feb 2015
    Location
    Kuna, Idaho
    Posts
    736
    My Cars
    Too Many Cars (NOT!)

    Weirdest CEL Ever! Maybe Not?

    Just got my 2/91 850 back up and running. Have a red CEL (left side cluster) that only lights up when idling. As soon as you use a little throttle it goes out, then comes back at idle. Everything I've read talks about a CEL staying on until the cause is fixed. Haven't seen one about this.
    Stumped...
    Mike Drives:
    BMW's
    E24 - 635CSiA - (1) 1985 (US)
    E24 - 635CSi - (1) 1985 (EC)
    E31 - 850iA - (1) 1991 (Black)
    E31 - 850iA - (1) 1991 (Calypso Red)

    E32 - 740iA - (1) 1994
    E32 - 750iA - (1) 1990 (Not an "L") (EC German National)
    E32 - 735iL - (2) 1990
    E32 - 750iL - (1) 1990

    E38 - 740iLA - (2) (1) 1997 & (1) 1998
    E38 - 750iLA - (1) 1998
    E38 - 740iA - (1) 2000 "Short Sport"
    E39 - 528iA - (2) - 2000 & (1) 1997
    Also:
    2015 Ram 3500 Dually, Cumins 6.7, Std.Cab. Long box 4x4 (To haul all this junk when necessary)
    2014 Dodge Dart Rallye (Daily Driver)
    2007 Mercedes Benz CL600 (Brabus SV12S)
    Mercedes Benz SL's - (1) (2002) & (1) 1999 500 - (1) 1999 600
    1967 Buick Riviera (2)

  2. #2
    Join Date
    Jun 2011
    Location
    NY, NY
    Posts
    298
    My Cars
    84 633, 91 M5, 91 850
    Have you done the stomp test?

  3. #3
    Join Date
    Oct 2016
    Location
    Montgomery, AL
    Posts
    212
    My Cars
    '92 850i 6-speed (SOLD)
    Deleted . . .
    Last edited by Sniff38; 09-19-2017 at 09:15 AM. Reason: Error in info

  4. #4
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Quote Originally Posted by masbury View Post
    Just got my 2/91 850 back up and running. Have a red CEL (left side cluster) that only lights up when idling. As soon as you use a little throttle it goes out, then comes back at idle. Everything I've read talks about a CEL staying on until the cause is fixed. Haven't seen one about this.
    Stumped...
    Maf is failing. Do you have k&n filters installed?

  5. #5
    Join Date
    Feb 2015
    Location
    Kuna, Idaho
    Posts
    736
    My Cars
    Too Many Cars (NOT!)
    Dragon850 - No, I have completely stock intakes and filters, in fact, just installed new air filters. Everything is new from the intake manifolds out up to MAF's.

    I ran codes with DIS GT1 v44 and 57 and got what is essentially o2 sensors connected backwards. One bank too rich the other too lean, which is the only codes I received. I then switched the connections and received codes telling me that both banks were too lean, which tells me they are now connected correctly except for the too lean (both banks) error. Could the MAF's failing cause this, is it the O2 sensors both failing at the same time? I am also getting an EML error with light, that one or the other is disconnected after changing the O2 sensor connections. Could it be both O2's and MAF's simultaneously? The car has 166k on it and I don't know it's history. I do have a pair of known working MAF's off my '90 E32 V12 that I can try. It's a German spec car, but the MAF'S should be the same.

    I will swap the MAF's, re-run codes and report back. If there is anything else that you can think of, please let me know.

    Thanks
    Mike Drives:
    BMW's
    E24 - 635CSiA - (1) 1985 (US)
    E24 - 635CSi - (1) 1985 (EC)
    E31 - 850iA - (1) 1991 (Black)
    E31 - 850iA - (1) 1991 (Calypso Red)

    E32 - 740iA - (1) 1994
    E32 - 750iA - (1) 1990 (Not an "L") (EC German National)
    E32 - 735iL - (2) 1990
    E32 - 750iL - (1) 1990

    E38 - 740iLA - (2) (1) 1997 & (1) 1998
    E38 - 750iLA - (1) 1998
    E38 - 740iA - (1) 2000 "Short Sport"
    E39 - 528iA - (2) - 2000 & (1) 1997
    Also:
    2015 Ram 3500 Dually, Cumins 6.7, Std.Cab. Long box 4x4 (To haul all this junk when necessary)
    2014 Dodge Dart Rallye (Daily Driver)
    2007 Mercedes Benz CL600 (Brabus SV12S)
    Mercedes Benz SL's - (1) (2002) & (1) 1999 500 - (1) 1999 600
    1967 Buick Riviera (2)

  6. #6
    Join Date
    Jun 2008
    Location
    SF Bay Area
    Posts
    3,778
    My Cars
    Supercharged 850ci
    Quote Originally Posted by masbury View Post
    Dragon850 - No, I have completely stock intakes and filters, in fact, just installed new air filters. Everything is new from the intake manifolds out up to MAF's.

    I ran codes with DIS GT1 v44 and 57 and got what is essentially o2 sensors connected backwards. One bank too rich the other too lean, which is the only codes I received. I then switched the connections and received codes telling me that both banks were too lean, which tells me they are now connected correctly except for the too lean (both banks) error. Could the MAF's failing cause this, is it the O2 sensors both failing at the same time? I am also getting an EML error with light, that one or the other is disconnected after changing the O2 sensor connections. Could it be both O2's and MAF's simultaneously? The car has 166k on it and I don't know it's history. I do have a pair of known working MAF's off my '90 E32 V12 that I can try. It's a German spec car, but the MAF'S should be the same.

    I will swap the MAF's, re-run codes and report back. If there is anything else that you can think of, please let me know.

    Thanks
    With the EML light on you likely have failing throttles that are not operating properly, you can send them to me for a rebuild if you'd like. I would start there...
    What does DIS tell you when you pull errors from EML module? "Throttle valve" fault or something similar?
    I also suggest disconnecting the batteries for 10 min after you plugged the o2 sensors in properly so the computers can relearn the adaptations correctly from the start.

  7. #7
    Join Date
    Feb 2015
    Location
    Kuna, Idaho
    Posts
    736
    My Cars
    Too Many Cars (NOT!)
    Dragon850;

    Interesting results today. Borrowed the MAF's from my 1990 E32 750i and prior to installing them in the 850, I cleared all the codes with DIS GT1 V44. Installed both MAF's, test drove, there was no red CEL during the drive, came back to my shop and re-ran DIS and lo and behold no codes at all... No O2 codes, EML codes nor anything. It appears that both my MAF's are bad and seems to have been triggering all the codes. Unbelievable! However, there is one small problem. The orange CEL on the right side of the cluster stays on after start, but then goes off after driving the car, say within a minute. What is that CEL and without any codes what can it mean?

    Still scratching the head...
    Mike Drives:
    BMW's
    E24 - 635CSiA - (1) 1985 (US)
    E24 - 635CSi - (1) 1985 (EC)
    E31 - 850iA - (1) 1991 (Black)
    E31 - 850iA - (1) 1991 (Calypso Red)

    E32 - 740iA - (1) 1994
    E32 - 750iA - (1) 1990 (Not an "L") (EC German National)
    E32 - 735iL - (2) 1990
    E32 - 750iL - (1) 1990

    E38 - 740iLA - (2) (1) 1997 & (1) 1998
    E38 - 750iLA - (1) 1998
    E38 - 740iA - (1) 2000 "Short Sport"
    E39 - 528iA - (2) - 2000 & (1) 1997
    Also:
    2015 Ram 3500 Dually, Cumins 6.7, Std.Cab. Long box 4x4 (To haul all this junk when necessary)
    2014 Dodge Dart Rallye (Daily Driver)
    2007 Mercedes Benz CL600 (Brabus SV12S)
    Mercedes Benz SL's - (1) (2002) & (1) 1999 500 - (1) 1999 600
    1967 Buick Riviera (2)

  8. #8
    Join Date
    Jan 2004
    Location
    Toronto, Canada
    Posts
    1,330
    My Cars
    BMW 850CSi
    The orange Check light that disappears after a min or so is not the CEL, but rather Check...as in, Chcek the MID for error/trouble messages.

  9. #9
    Join Date
    Feb 2015
    Location
    Kuna, Idaho
    Posts
    736
    My Cars
    Too Many Cars (NOT!)
    So, nothing to worry about? Wow, what a relief that is.

    Thank you all.
    Mike Drives:
    BMW's
    E24 - 635CSiA - (1) 1985 (US)
    E24 - 635CSi - (1) 1985 (EC)
    E31 - 850iA - (1) 1991 (Black)
    E31 - 850iA - (1) 1991 (Calypso Red)

    E32 - 740iA - (1) 1994
    E32 - 750iA - (1) 1990 (Not an "L") (EC German National)
    E32 - 735iL - (2) 1990
    E32 - 750iL - (1) 1990

    E38 - 740iLA - (2) (1) 1997 & (1) 1998
    E38 - 750iLA - (1) 1998
    E38 - 740iA - (1) 2000 "Short Sport"
    E39 - 528iA - (2) - 2000 & (1) 1997
    Also:
    2015 Ram 3500 Dually, Cumins 6.7, Std.Cab. Long box 4x4 (To haul all this junk when necessary)
    2014 Dodge Dart Rallye (Daily Driver)
    2007 Mercedes Benz CL600 (Brabus SV12S)
    Mercedes Benz SL's - (1) (2002) & (1) 1999 500 - (1) 1999 600
    1967 Buick Riviera (2)

Similar Threads

  1. First and last race EVER (maybe not ever)
    By Jahseso in forum Kill Stories
    Replies: 20
    Last Post: 05-13-2008, 12:38 AM
  2. First ever wash with me as owner!!(56K maybe not)
    By Bimmer14PA in forum BMW Rides & Events
    Replies: 13
    Last Post: 03-31-2006, 09:33 AM
  3. here's a new idea (maybe not)
    By Filip75 in forum Forum Software Questions & Suggestions
    Replies: 11
    Last Post: 08-16-2002, 01:52 AM
  4. Replies: 1
    Last Post: 06-28-2002, 08:52 PM
  5. Replies: 3
    Last Post: 06-26-2002, 11:34 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •