Location: Dallas, TX
Posts: 58
My VIN: 3713
Just when I think I have everything else sorted out with this car, I start the motor and right away it's something else. A distinct medium pitch whine coming from the motor. It changes pitch, or goes up with the rpms. I was thinking maybe a pully- like the crank pully. It's not a high pitch squeal, but a medium pitch wine.
I have a video of it on my cell but for some reason it won't upload to photobucket.
Any clues?
Location: Atlanta-ish
Posts: 2,218
My VIN: 5311
Club(s): (SEDOC) (DCUK)
Maybe you've got a belt slipping, or something's vibrating against something else?
Sorry I'm not much of help right off the bat. Hard to diagnose without sitting in front of the engine, even harder when you can't hear what it sounds like.
- Chris
what
Location: Dallas, TX
Posts: 58
My VIN: 3713
Thanks-It's not a belt- I am trying to figure out a way to upload the vid.
Location: North GA
Posts: 6,177
Club(s): (SEDOC) (DCUK)
Drop the belt(s) and run it just long enough to see if goes away... If so, you can probably spin the individual components and tell which one is the culprit...
Location: Sacramento-ish
Posts: 4,408
My VIN: 02100
Club(s): (NCDMC) (DCUK)
Could be a vacuum leak too if it changes pitch with engine RPM.
Jon
1981 DMC-12 #02100. July 1981. 5-speed, black, grooved w/flap.
restoration log, March 2011 to present
full and detailed photo restoration log
Location: Dallas, TX
Posts: 58
My VIN: 3713
If anyone knows how to post a vid, i can email it to you?? Doubt it's a vacuum leak. Sounds mechanical.
Location: Atlanta-ish
Posts: 2,218
My VIN: 5311
Club(s): (SEDOC) (DCUK)
What format is the video? Can't you just upload it to YouTube?
- Chris
what
Location: Dallas, TX
Posts: 58
My VIN: 3713
I think it's the alternator takin a dump. Just started the car and now the charge is sitting right in the middle, 13, at 1000 rpms. Turn on the lights and it drops below 13. It's still charging because when I give it gas it goes up slightly, but just yesterday it would sit at 15 at idle. Doesn't sound significant but I raised my idle a month ago so it would be at 15 at the minimum.
Location: North GA
Posts: 6,177
Club(s): (SEDOC) (DCUK)
Don't put too much into what the gauge says. Besides being inaccurate, the voltage shown will vary depending on battery condition, charge, temperature, ect., the more it is putting out the more it will whine. Put a meter on it (13.5 is normal for stock. 14.2 for modern/aftermarket).
The sound they make when going bad (electrically) doesn't sound mechanical.
Location: Northern NJ
Posts: 8,583
My VIN: 10757 1st place Concourse 1998
The alternator could certainly be making a whining noise but to some degree that is normal. Especially if it is putting out a lot of electric because of a lot of loads or a discharged battery. Other sources include:
Both idler pulleys for the A/C
Water pump
As suggested, you can remove the belts one at a time and see if the noise goes away. If you suspect a dying alternator you can go to most any auto shop and they will check your battery and alternator for free.
David Teitelbaum
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