Re: [MV] HMMWV Engine whine

From: chance wolf (timberwolf@lynx.bc.ca)
Date: Sun Oct 15 2000 - 20:30:03 PDT


At 08:55 PM 10/15/00 -0400, J Brennan wrote:
>I Have a '93 M1038 HMMWV. When it heats up to around 190+ degrees I start
>hearing a whining sound. The sound is linked to the RPM's of the engine.
>That is as I press the pedal the whine pitch goes higher and lower as I let
>off the pedal. I also hear it change pitch as I turn the steering wheel.
>I've checked fluids in the automatic transmission and the power steering
>reservoir and both are fine. I've tried listening to exactly where it's
>coming from but the diesel engine is to load to get a lock on it. When I
>first start it up and drive it it's fine until it hits 190+ degrees. Any
>thought? Thanks.

Yup. If it's like the earlier 998's, what you're hearing is the hydraulic
clutch fan kick in - usually around that very temperature, though
we've some at work that leave it until 200 or so.

It was a bit disconcerting when I first started driving them, as I wasn't
used to that sort of noise emanating from a power plant that was
working as advertised.

If you look above where your PCB connection goes through the firewall
(i.e., under the hood) you'll see a hydraulic switch and a black box that
terminates in a two connector plug which hooks up to a similar plug
in the harness. If you disconnect that while the vehicle is at idle, you'll
see the fan kick in, and probably hear the no longer mysterious noise.

Have fun,

Andy Hill
MVPA 9211
Vancouver, B.C.



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