R3VLimited Forums

Go Back   R3VLimited Forums > E34/E28 Forums > General 5 Series Technical

Reply
 
Thread Tools
Old 12-14-2015, 02:52 PM   #1
EyExR
Mod Crazy
 
EyExR's Avatar
 
Join Date: Jan 2011
Location: Lawn_Guy Land, NY
Posts: 793
Whirring Engine Noise on M50

Hi all. I've got a new issue with my 93 525i Touring. I'm hearing a whirring noise coming from the engine and it seems to be coming from the head somewhere... It gets higher and lower in pitch with engine speed. If I keep the car in park or neutral it happens as well. Would that eliminate the tranny as a culprit?

I took off all the accessory belts and it's still there. Any ideas on what would cause this? VANOS? Cams? Something else?
EyExR is offline   Reply With Quote
Old 12-16-2015, 03:42 PM   #2
EyExR
Mod Crazy
 
EyExR's Avatar
 
Join Date: Jan 2011
Location: Lawn_Guy Land, NY
Posts: 793
Bueller?
EyExR is offline   Reply With Quote
Old 12-16-2015, 09:47 PM   #3
gkurey
E30 Modder
 
gkurey's Avatar
 
Join Date: Mar 2010
Location: San Diego, CA
Posts: 878
My thought is vanos or timing chains...hard to saw without hearing it
__________________

15 AW 328i
89 AW S52 325is, build thread ---> http://www.r3vlimited.com/board/showthread.php?t=167428
Custom CNC Goods!
http://www.planeform.com
gkurey is offline   Reply With Quote
Old 12-16-2015, 09:59 PM   #4
Coupelx
Advanced Member
 
Join Date: Oct 2013
Location: NW Oklahoma
Posts: 169
Most likely the vanos, mine has a slight vanos rattle that settles into a steady sound when the engine is warm.
Coupelx is offline   Reply With Quote
Old 12-17-2015, 12:08 PM   #5
EyExR
Mod Crazy
 
EyExR's Avatar
 
Join Date: Jan 2011
Location: Lawn_Guy Land, NY
Posts: 793
Thing is, it's not a rattle at all. And now my car is bogging down and hesitating.

My plan is to probe around with a stethoscope this weekend to hone in on the source of the noise. But it really seems to be coming from the intake... Very strange.

I'll get a recording of it and post up soon.

Thanks for the replies!
EyExR is offline   Reply With Quote
Old 12-26-2015, 01:39 PM   #6
Northern
R3VLimited
 
Northern's Avatar
 
Join Date: Nov 2010
Location: Halifax, N.S.
Posts: 2,684
Send a message via ICQ to Northern Send a message via AIM to Northern Send a message via MSN to Northern Send a message via Yahoo to Northern
clutch fan?
__________________
E30VON_NS 
Quote:
Originally Posted by priapism View Post
My girl don't know shit, but she bakes a mean cupcake.
Quote:
Originally Posted by shameson View Post
Usually it's best not to know how much money you have into your e30
Northern is offline   Reply With Quote
Old 12-27-2015, 09:05 AM   #7
EyExR
Mod Crazy
 
EyExR's Avatar
 
Join Date: Jan 2011
Location: Lawn_Guy Land, NY
Posts: 793
Quote:
Originally Posted by Northern View Post
clutch fan?
No. I took that off...
EyExR is offline   Reply With Quote
Old 01-03-2017, 10:57 AM   #8
Sirotto
Wrencher
 
Sirotto's Avatar
 
Join Date: Jul 2007
Location: Indy, Indiana
Posts: 251
Any update on this?

Does it seem to change withe electrical load?

I have the same issue and i am leaning towards the alt, might rebuild it and see what happens.
__________________
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." - Winston Churchill

"People sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf" -George Orwell
Sirotto is offline   Reply With Quote
Old 01-03-2017, 11:39 AM   #9
straight6pwr
No R3VLimiter
 
Join Date: Sep 2004
Location: Milwaukee,WI Stance: ha
Posts: 3,382
Send a message via AIM to straight6pwr
how about a large intake leak at the head? rushing air can make all kinds of noises and could certainly cause hesitation. you should be able to pinpoint the sound better with a make-shift stethoscope. or buy one at the store for $5
__________________
straight6pwr is offline   Reply With Quote
Old 01-10-2017, 09:32 AM   #10
Sirotto
Wrencher
 
Sirotto's Avatar
 
Join Date: Jul 2007
Location: Indy, Indiana
Posts: 251
Already vacuum checked, all new seals when the intake was off for the coolant sensor as well.

One thing that has me pointing to vanos is that i was playing with oils and found that my m50 likes 5w40 syn over everything else. The whirling sound changed with oil weight as well.

Incase nobody knew BMW now has 0w20 or 30 in the overhead oil system in all the dealerships and it is up to the tech to choose your oil weight now.
__________________
"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." - Winston Churchill

"People sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf" -George Orwell
Sirotto is offline   Reply With Quote
Old 01-10-2017, 11:13 AM   #11
gearheadE30
No R3VLimiter
 
gearheadE30's Avatar
 
Join Date: Jun 2007
Location: Indiana
Posts: 3,702
Alternator, idler pulleys, and water pump starting to fail would be the first things I'd look at. Possibly also the AC compressor clutch bearing failing. If you pull both belts and run it(briefly, so you don't overheat it), you should be able to isolate all of these.

VANOS usually rattles rather than whirring. I'm not really sure what would make a whirring noise in that system, as it's pretty simple.

Timing chain guides would be my internal bet. Known for failing eventually, and as they rub against the chains, there is definitely potential for them to make noise.

Very uncommon, but an issue mine had when I got it, was a failed thrust bearing on the intake cam. It only made a little noise though, surprisingly.



__________________

Project M42 Turbo
gearheadE30 is offline   Reply With Quote
Old 01-10-2017, 12:48 PM   #12
EyExR
Mod Crazy
 
EyExR's Avatar
 
Join Date: Jan 2011
Location: Lawn_Guy Land, NY
Posts: 793
I forgot to follow up on this. It was my clutch fan afterall. Northern was right!
The bearing seized and caused the fan to spin a full speed all the time. And it was out of balance causing the car to vibrate a lot. I guess when I took it off to test the sound I was hearing was normal engine noise - kind of a bonehead move on my part.

Dennis at OMG Motorworks actually spotted the problem in like two seconds. Swapped in a new fan and all is good again.
EyExR is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 12:59 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2004 - 2020 R3VLimited LLC