Tearing my hair out locating whistling/whining noise - Alfa Romeo Bulletin Board & Forums
 8Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old 07-25-2017, 05:49 PM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
Tearing my hair out locating whistling/whining noise

I've been trying to track down a whistling/whining noise coming from the engine compartment for the last 2 hours and am coming up short. It sounds like it is a significant air leak, but I have checked all hoses and hose connections, as well as replaced the hard plastic hose that sits on top of the cam cover. I have also checked the bellows hose connecting to the MAF, and all of the individual vacuum hoses. I have also replaced the AAV. It sounds upon closer inspection as if the sound is actually coming from the fuel injectors. Is that possible? I have made a short video of the noise to see if y'all can help me diagnose. Thanks in advance.

Link to video:

https://www.dropbox.com/s/rsh1hrexda...81%29.mp4?dl=0


Sent from my VS995 using Tapatalk

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i

Last edited by RenaissanceMan; 07-25-2017 at 06:40 PM.
RenaissanceMan is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old 07-25-2017, 06:11 PM
But Mad North-Northwest
Platinum Subscriber
 
Gubi's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area, CA
Posts: 9,802
A bad in-tank pump will make the main fuel pump whine, maybe you're hearing that through the fuel rail? Is this a new sound?
ghnl likes this.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
Gubi is offline  
post #3 of 21 (permalink) Old 07-25-2017, 06:12 PM
BB Janitor
Platinum SubscriberAdministratorSuper Moderator
 
ghnl's Avatar
 
Join Date: Oct 2005
Location: Mebane, NC
Posts: 16,258
Garage
The injectors make a faint clicking sound - you can rest a screwdriver on them and use it like a stethoscope to hear them operate. Which reminds me, a 2'-3' length of 1/2" hose make a good stethoscope to track down noises. It doesn't amplify the sound but it can help pinpoint the source (and keeps tender body parts away from hot &/or moving engine parts). A faulty injector seal could be the source of a vacuum leak. That might make a whining or whistling sound.

- - Eric
don't read this
~ 1984 Spider Veloce ~
- -~ 1981 GTV-6 ~
Mebane, North Carolina


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ghnl is offline  
Sponsored Links
Advertisement
 
post #4 of 21 (permalink) Old 07-25-2017, 06:20 PM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
Quote:
Originally Posted by ghnl View Post
The injectors make a faint clicking sound - you can rest a screwdriver on them and use it like a stethoscope to hear them operate. Which reminds me, a 2'-3' length of 1/2" hose make a good stethoscope to track down noises. It doesn't amplify the sound but it can help pinpoint the source (and keeps tender body parts away from hot &/or moving engine parts). A faulty injector seal could be the source of a vacuum leak. That might make a whining or whistling sound.
I hear the clicking sound. This whining noise is brand new. Literally just started out of the blue. I had done the stethoscope experiment as well and it keeps leading me to the injector area. The faulty injector seal is an interesting theory. Another observation is that the sound goes away when revving the motor or under load, and then comes back strong as the motor returns to idle speed. Still trying to post this video... The forum is not being very friendly with mp4 files..

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i
RenaissanceMan is offline  
post #5 of 21 (permalink) Old 07-25-2017, 06:31 PM
But Mad North-Northwest
Platinum Subscriber
 
Gubi's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area, CA
Posts: 9,802
Well, the manifold pressure sensor will whistle if it goes bad, but that's behind the passenger seat. Not sure if you'd hear it in the engine bay.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
Gubi is offline  
post #6 of 21 (permalink) Old 07-25-2017, 06:40 PM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
video link just added to original post.

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i
RenaissanceMan is offline  
post #7 of 21 (permalink) Old 07-25-2017, 07:45 PM
BB Janitor
Platinum SubscriberAdministratorSuper Moderator
 
ghnl's Avatar
 
Join Date: Oct 2005
Location: Mebane, NC
Posts: 16,258
Garage
You can try wiggling the injectors and pushing them in (towards the intake) to see if that changes/eliminates the sound. Or spraying some carb cleaner and watch if it gets sucked in. If so, that'd point to a faulty injector seal.

Starter motor isn't stuck 'engaged'?

- - Eric
don't read this
~ 1984 Spider Veloce ~
- -~ 1981 GTV-6 ~
Mebane, North Carolina


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ghnl is offline  
post #8 of 21 (permalink) Old 07-25-2017, 07:51 PM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
Quote:
Originally Posted by ghnl View Post
You can try wiggling the injectors and pushing them in (towards the intake) to see if that changes/eliminates the sound. Or spraying some carb cleaner and watch if it gets sucked in. If so, that'd point to a faulty injector seal.

Starter motor isn't stuck 'engaged'?
Nah, starter motor is disengaging properly. This is definitely a whistling noise either coming from the injector area or the AAV area... I will try the carb cleaner and wiggling ideas and report back. Thanks-

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i
RenaissanceMan is offline  
post #9 of 21 (permalink) Old 07-26-2017, 04:01 PM
Registered User
 
Join Date: Aug 2004
Location: SF Bay area, CA
Posts: 317
The only whistle sound I know would come from the ignition advance sensor behind the front seats on the passenger side. It can be quite loud.
pabeaver is offline  
post #10 of 21 (permalink) Old 07-26-2017, 04:33 PM
Senior Member
Gold Subscriber
 
Norseman50's Avatar
 
Join Date: Apr 2014
Location: Bellevue, WA
Posts: 1,462
Garage
Kind of sounds like metal on metal high rpm scratching sort of whine in the video to me.
Norseman50 is online now  
post #11 of 21 (permalink) Old 07-26-2017, 04:36 PM
BB Janitor
Platinum SubscriberAdministratorSuper Moderator
 
ghnl's Avatar
 
Join Date: Oct 2005
Location: Mebane, NC
Posts: 16,258
Garage
Take off the alternator belt then start the motor and see if the sound remains. If not, it could be the water pump or the alternator. Or perhaps the crankshaft pulley is rubbing on the cross member or the fan is rubbing on the shroud (can happen with saggy motor mounts)
alfabeach likes this.

- - Eric
don't read this
~ 1984 Spider Veloce ~
- -~ 1981 GTV-6 ~
Mebane, North Carolina


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ghnl is offline  
post #12 of 21 (permalink) Old 07-26-2017, 08:46 PM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
Thanks for the additional ideas everyone!

Couple more clues/points:

This really does sound like an air leak type of noise when listening up close and not metallic. Listening back to my low quality video I can see though how one might think it is metal on metal though.

Engine mounts and tranny mount are new with only about 400 miles on them. Not seeing any sagging or evidence of spinning contact with anything.

When first starting the car cold, the noise is not there. It starts after running for a couple of minutes.

If I push on/around the area of the rubber ring that joins the hard plastic intake tube to the throttle body, it slightly changes the volume of the noise. I carefully inspected the rubber ring for cracks and leaks but could not find any. The clamps are tight.

Any ideas?

Sent from my VS995 using Tapatalk

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i
RenaissanceMan is offline  
post #13 of 21 (permalink) Old 07-26-2017, 09:26 PM
But Mad North-Northwest
Platinum Subscriber
 
Gubi's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area, CA
Posts: 9,802
Well, that plastic intake tube can crack internally. If you overtighten the screws you can get a very slight air leak from the screw holes to the center of the tube...seen that at least once before on the BB.
John533i likes this.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
Gubi is offline  
post #14 of 21 (permalink) Old 07-26-2017, 09:47 PM
Senior Member
Gold Subscriber
 
Norseman50's Avatar
 
Join Date: Apr 2014
Location: Bellevue, WA
Posts: 1,462
Garage
Only whistles when hot? Cooling system perhaps? Hot water or steam pushing past the thermostat? Have you checked your coolant level lately?

Last edited by Norseman50; 07-26-2017 at 10:00 PM.
Norseman50 is online now  
post #15 of 21 (permalink) Old 07-29-2017, 07:26 AM Thread Starter
Registered User
 
RenaissanceMan's Avatar
 
Join Date: Sep 2009
Location: Music City, USA
Posts: 466
Well, I finally found it. Good grief. Check out the cut in the plenum hose.

Sent from my VS995 using Tapatalk
ghnl likes this.

Adam in Nashville: '72 Alfa Romeo GTV 2000 - '86 Alfa Romeo Spider Veloce - '74 BMW 2002tii - '90 BMW E30/S52 - '05 BMW X5 - '06 BMW 325i
RenaissanceMan is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome