Whistling noise behind dash when towing, O/D off

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miekmiek

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Sep 23, 2018
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Location
Spokane, WA
Ram Year
1998
Engine
5.9L
I have a 1998 Dodge Ram Laramie 1500 4x4 with the 5.9L engine. Just towed a trailer for the first time.

At 2300-3000 RPM with overdrive off (disengaged), there is a high pitched whistling noise coming from behind the dashboard. It decreases when I let off the gas, or when I get to about 3000 RPM.

When I re-engage the overdrive (turn it on) the noise goes away completely. It sounds to my ears like a vacuum leak, or in other words, not mechanical.

Any thoughts about or previous encounters with this issue?
 
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miekmiek

Junior Member
Joined
Sep 23, 2018
Posts
2
Reaction score
0
Location
Spokane, WA
Ram Year
1998
Engine
5.9L
I tested it out today with no load being towed, and with the overdrive turned off the whistling noise occurred from 2700-3000 RPM.
 
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