High-pitched whine from somehere in the engine...

Tiny
MUNDANEATROCITY
  • MEMBER
  • 2000 DODGE DAKOTA
  • 2.5L
  • 4 CYL
  • 2WD
  • MANUAL
  • 125,000 MILES
After about five minutes of engine run-time, a high-pitched whine will start to emanate from the engine. The noise seems to respond to engine load; it will occur at idle, and when I take off it will briefly pitch down, as if it was responding to the increased load on the engine. However, it isn't regular -- it might stop altogether, and then re-appear, sometimes for just a second or two, or it will stop completely. There doesn't seem to be a predictable pattern, other than the five minute thing. The engine seems to operate exactly as it always does.

I'm thinking maybe it's a pulley or belt tensioner, perhaps. Could it be a vacuum leak, as some have suggested? I'm pretty much at a loss here.
Do you
have the same problem?
Yes
No
Thursday, May 8th, 2014 AT 12:54 PM

4 Replies

Tiny
HMAC300
  • EXPERT
Belt and tensioner replacement is recommended at 60k take the belt off and run engine see if it down' the same thing if not it's a accessory problem.
Was this
answer
helpful?
Yes
No
Thursday, May 8th, 2014 AT 3:56 PM
Tiny
MUNDANEATROCITY
  • MEMBER
I replaced both tensioner pulleys and the belt (I even tried the shorter belt, bypassing the AC compressor), with no change. In fact, the whining squeal (for lack of a better term) is louder than ever.

Also: I've noticed that the noise is more insistent, more strident, after the truck is first started in the morning, when the ambient temperature is lower, after being parked overnight. After shutting off the engine for a few minutes and re-starting, the noise disappears, only to re-appear after a few minutes. Later in the day, after the ambient temperature rises, the noise becomes rather erratic and unpredictable, and will even stop occasionally, only to reappear later.

With no "check engine" light and no other indication of a problem, I'm at a complete loss.
Was this
answer
helpful?
Yes
No
Wednesday, May 28th, 2014 AT 1:09 PM
Tiny
HMAC300
  • EXPERT
Other than being maybe an alternator problem like abearing your best bet is to have a local pro look at it and give you a better diagnosis if possible.
Was this
answer
helpful?
Yes
No
Wednesday, May 28th, 2014 AT 1:13 PM
Tiny
MUNDANEATROCITY
  • MEMBER
Yeah, I've been thinking -- on and off -- that it could be the alternator. Among all sorts of wildly improbable things. Money issues pretty much preclude taking it to a shop at the moment, unfortunately.

Thanks for your input -- I really appreciate it.
Was this
answer
helpful?
Yes
No
Wednesday, May 28th, 2014 AT 1:23 PM

Please login or register to post a reply.

Recommended Guides