Results 1 to 8 of 8

Thread: 735i (very) Cold Start Video - Possible Vacuum Leak after 45 seconds?

  1. #1
    Join Date
    Jul 2012
    Location
    South Yarmouth MA
    Posts
    550
    My Cars
    11/87 735i & 735il P/C

    Question 735i (very) Cold Start Video - Possible Vacuum Leak after 45 seconds?

    I always hear a whining sound after 45-60 seconds of starting the car when cold. Seems to start off almost perfectly, but then the whining starts and the idle seems to oscillate. Also note the weird behavior when giving it a little gas and then letting off the throttle quickly.

    All vacuum & air-intake hoses have been replaced. The ICV and AFM have been cleaned/tested, along with the TPS.

    Does this sound like a bad valve cover gasket? Intake manifold gaskets?? Any input is appreciated!

    https://drive.google.com/file/d/1G4R...ew?usp=sharing
    Last edited by CamE32; 01-12-2019 at 11:27 AM.
    1983 4-spd Mercedes 240d w/403k - Sold!

    11/87 E32 735iA w/45k - Daily Driver (finally!)

    04/88 E32 735iL - Parts Car

  2. #2
    Join Date
    Apr 2017
    Location
    Chatham, Ontario, Canada
    Posts
    13
    My Cars
    1988 BMW 735i
    Mine makes the same sound as that, although I think of it being more like a whistle sound.
    I haven't figured out what causes it but on my car at least, it sounds like it's coming from the passenger side of the engine bay.


    Sent from my SM-G950W using Tapatalk

  3. #3
    Join Date
    Jul 2012
    Location
    South Yarmouth MA
    Posts
    550
    My Cars
    11/87 735i & 735il P/C
    Whistling is a much better description, thank you. And mine seems to be emanating from the passenger side also!
    1983 4-spd Mercedes 240d w/403k - Sold!

    11/87 E32 735iA w/45k - Daily Driver (finally!)

    04/88 E32 735iL - Parts Car

  4. #4
    Join Date
    Apr 2017
    Location
    Chatham, Ontario, Canada
    Posts
    13
    My Cars
    1988 BMW 735i
    I'm not sure but I'm wondering if it isn't air moving through the intake that's causing it, but I haven't looked at mine close enough to tell.


    Sent from my SM-G950W using Tapatalk

  5. #5
    Join Date
    May 2012
    Location
    Boynton Beach, Florida
    Posts
    1,526
    My Cars
    1990 735I (E32) M30
    Imagine if a 1/2 second shot of belt spray on your three belts made it all go away. Sometimes our M30 motors require a bit of magic.

    1990 735I (Auto) E32 Feb 1990 to Present
    1996 Z3 Roadster (5 Speed) E36/7 Jan 1999 to Dec 1999
    1983 733I (5 Speed) E23 April 1983 to Feb 1990
    https://www.youtube.com/watch?v=2d4tHoHGaJo
    https://1drv.ms/v/s!Av20xCMMocSsyEpl...h_oOk?e=ekIcAT







  6. #6
    Join Date
    Jul 2012
    Location
    South Yarmouth MA
    Posts
    550
    My Cars
    11/87 735i & 735il P/C
    Quote Originally Posted by CroughtonE32 View Post
    Imagine if a 1/2 second shot of belt spray on your three belts made it all go away. Sometimes our M30 motors require a bit of magic.
    Really??? I’ll try it if you think that’s actually symptomatic of the whistling noise. I only question it because I had them all replaced within a year ago.
    1983 4-spd Mercedes 240d w/403k - Sold!

    11/87 E32 735iA w/45k - Daily Driver (finally!)

    04/88 E32 735iL - Parts Car

  7. #7
    Join Date
    May 2012
    Location
    Boynton Beach, Florida
    Posts
    1,526
    My Cars
    1990 735I (E32) M30
    Quote Originally Posted by CamE32 View Post
    Really??? I’ll try it if you think that’s actually symptomatic of the whistling noise. I only question it because I had them all replaced within a year ago.
    I’m just throwing it out there. Might work. Could be coming from a pulley after warm up. Hell, if I didn’t want the world jumping in, I’d blame the whistle on our infamous “mustard relay”. But I won’t. Only because it’s Sunday.


    Sent from my iPhone using Tapatalk
    1990 735I (Auto) E32 Feb 1990 to Present
    1996 Z3 Roadster (5 Speed) E36/7 Jan 1999 to Dec 1999
    1983 733I (5 Speed) E23 April 1983 to Feb 1990
    https://www.youtube.com/watch?v=2d4tHoHGaJo
    https://1drv.ms/v/s!Av20xCMMocSsyEpl...h_oOk?e=ekIcAT







  8. #8
    Join Date
    Jan 2017
    Location
    United States
    Posts
    75
    My Cars
    1989 BMW 735i
    That sounds very much like a belt/pulley issue to me. The belt dressing is where I would start, then perhaps check the bearings in your alternator.
    I haven't had it on our 735, but I have had a very similar sound on some of our other vehicles. On one it turned out to be the water pump.

Similar Threads

  1. Help finding possible Vacuum leak...
    By Titansilber in forum Forced Induction
    Replies: 23
    Last Post: 05-19-2011, 05:45 AM
  2. Possible Vacuum Leak?
    By bimmerpwr in forum Forced Induction
    Replies: 4
    Last Post: 02-24-2006, 10:29 AM
  3. Noticed a something possibly vacuum leak ?
    By s52e368 in forum Forced Induction
    Replies: 11
    Last Post: 02-07-2006, 01:27 PM
  4. Very very cold starts
    By mdibatti in forum 1991 - 1999 (E36)
    Replies: 29
    Last Post: 10-09-2005, 06:35 PM
  5. Rattle, clatter, whine at very cold start (318/M42)
    By hccyong in forum 1991 - 1999 (E36)
    Replies: 12
    Last Post: 01-13-2004, 11:20 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
  •