Cruising speed noise at 1900 RPM Range

jogger

Member
I have an annoying drone-like noise at 1950 to 2000 RPM.
Not a wheel bearing and i don't think a rear end.
Only makes the noise while cruising at 80 kph to 87 kph.
Seems like an exhaust harmonic maybe or torque converter lock up noise?
Is this possible at such a specific condition? Anybody else have any symptoms or ideas?
Thanks
:thinking:
 

sailquik

Well-known member
jogger,
Have a look at the center steady bearing on the driveshaft.
Also, if the frequency does not change when you downshift to 4th gear it could be a driveshaft balance issue, but that's more
common on the later NCV3 Sprinters.
Question.....are you "cruising" @ 80-87 KPH (37.2-41.6 mph) in overdrive all the time?
Roger
 

jogger

Member
Pretty likely it is in TC lockup and overdrive. It is a little higher than your conversion though around 50 to 55 mph. If i down shift whilst in cruise control, the revs are up, the speed is the same and the noise is gone.
Probably not anything past the transmission output shaft.
Wondering if RSN can manifest during this range.
Incidently, if I match the engine revs to the 1900-2000 RPM in 3 rd or 4th the noise is there.
Hard to nail this one down.:idunno:
 

jogger

Member
Hard to tell as the regular engine noise overwhelms all.
I can't say I hear it then, that is why I am dreading that its torque converter lock up, one of the few things that turns at crankshaft speed and can turn on/off while moving.
I'm gonna wait till it warms up and crawl around underneath and check all the exhaust components anyway.
 

jb21cri

Member
in my rsn experience it occurred between 15-25 mph only and 90% of the time upon decelleration.with the 03 cargo it magnified it to the point that i thought it was suspension or chassis related.thanks again to doktor A for the fix,and to everyone else on this forum for the invalueable information that i have gathered here.:bow:
 

berwin823

New member
I am also having an engine noise in the 1800 to 2000 rpm range. See my thread "engine noise" in the Sprinter Talk forum. I have a mp3 recording of the noise in the thread. Is your noise like mine?

Bob (berwin823)
 

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