I have a 2010 Winnebago View built on a 2008 Sprinter Chassis. While on our first extended trip I experienced an occasional strange "bump" while at slow speeds (anywhere from 10 to 45 mph) under very light acceleration. It seemed like the engine was at high torque but had not yet down shifted. There would be a noticeable "jerk" followed by an increase acceleration, sometimes after a down shift and often without down shifting. For example, if I rolled up to a light which has just turned green and I gently apply pressure to the accelerator I occasionally feel this "bump" and then the vehicle will increase speed normally. As another example, while driving on a level roadway at 40-45 mph if I slowly increase pressure on the accelerator to increase speed I will occasionally experience this "bump" before the vehicle increases speed. I must emphasize that the use of the accelerator is very light pressure. If I use the accelerator aggressively this behavior does not occur. Two Sprinter repair facilities have run transmission diagnostics and found nothing out of normal readings. Does anyone have suggestions which I can pass on to my mechanic? I would very much appreciate any feed back.
Shifting problem?
- Thread starter ron4adams
- Start date
piper1
Resident Oil Nerd.
B
boxcar
Guest
Your description sounds quite familiar from what I've read as well as my experiences driving Sprinters, just as you are describing, Ron. The Sprinter Store, a division of Upscale Auto in Tualitin, Oregon (just south of Portland), have the following improvement available... from their website:
"Transmission Brace: RSN, or "rumble strip noise" as many describe it, is a common problem with the Sprinter. It is a buzzing noise along with a vibration that occurs when shifting into higher gears at slower speeds and RPMs. We have developed a Transmission Cross Member Brace Kit to dramatically reduce the problem and improve shifting. Now available for $89.95 plus shipping and handling."
http://www.upscaleauto.com/sprinter_parts.htm
Have visited the shop recently in anticipation of my upcoming Sprinter purchase. It's as clean a shop as you'll ever find & a fine, knowledgeable crew there as well. Sprinters are what they do & they do them well.
Also from their website:
"Got RSN?
RSN, or "rumble strip noise"... As we have long suspected, RSN is resonance caused by torsional vibrations. It radiates from the rear engine support, which we prefer to call the transmission cross member mount. This mount is stamped steel and only .114” or 2.85mm thick. For lack of a better description, it is stamped in an upside down U shape. It is mounted in the vehicle in this “upside down” position with the transmission tail housing mounted on top of it. The transmission’s torsional vibration and “shudder” during shifting causes the transmission cross member mount to vibrate and resonate. You can feel the vibrations in the chassis and hear the resonance as a metallic buzz similar to an exhaust vibration noise. The factory vibration dampener is not sufficient to take care of RSN. In my estimation, the gauge of metal used in the transmission cross member mount is not adequate. In addition, the isolation mount between the transmission tail shaft and the cross member mount is rather wimpy which adds to the vibration and resonance.
We have developed a brace to strengthen the transmission cross member mount. Installation is very simple and requires drilling two 5/16”/8mm holes. The brace does not eliminate RSN but does dramatically reduce the noise, vibrations and frequency of occurrence. It also creates a more positive shift because the brace allows the torque to be transferred into shifting rather than vibrating the chassis. RSN should not be confused with transmission shudder, which occurs during shifting at higher speeds. Our transmission brace will not correct transmission shudder problems."
http://www.upscaleauto.com/specialty_parts.htm
.
"Transmission Brace: RSN, or "rumble strip noise" as many describe it, is a common problem with the Sprinter. It is a buzzing noise along with a vibration that occurs when shifting into higher gears at slower speeds and RPMs. We have developed a Transmission Cross Member Brace Kit to dramatically reduce the problem and improve shifting. Now available for $89.95 plus shipping and handling."
http://www.upscaleauto.com/sprinter_parts.htm
Have visited the shop recently in anticipation of my upcoming Sprinter purchase. It's as clean a shop as you'll ever find & a fine, knowledgeable crew there as well. Sprinters are what they do & they do them well.
Also from their website:
"Got RSN?
RSN, or "rumble strip noise"... As we have long suspected, RSN is resonance caused by torsional vibrations. It radiates from the rear engine support, which we prefer to call the transmission cross member mount. This mount is stamped steel and only .114” or 2.85mm thick. For lack of a better description, it is stamped in an upside down U shape. It is mounted in the vehicle in this “upside down” position with the transmission tail housing mounted on top of it. The transmission’s torsional vibration and “shudder” during shifting causes the transmission cross member mount to vibrate and resonate. You can feel the vibrations in the chassis and hear the resonance as a metallic buzz similar to an exhaust vibration noise. The factory vibration dampener is not sufficient to take care of RSN. In my estimation, the gauge of metal used in the transmission cross member mount is not adequate. In addition, the isolation mount between the transmission tail shaft and the cross member mount is rather wimpy which adds to the vibration and resonance.
We have developed a brace to strengthen the transmission cross member mount. Installation is very simple and requires drilling two 5/16”/8mm holes. The brace does not eliminate RSN but does dramatically reduce the noise, vibrations and frequency of occurrence. It also creates a more positive shift because the brace allows the torque to be transferred into shifting rather than vibrating the chassis. RSN should not be confused with transmission shudder, which occurs during shifting at higher speeds. Our transmission brace will not correct transmission shudder problems."
http://www.upscaleauto.com/specialty_parts.htm
.
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cedarsanctum
re: Member
Certainly describes a bad EGR valve in my experience.
B
boxcar
Guest
Have learned something from this thread, thanks guys: Do not confuse a bump for a pesky rumble. 
'Twas the "...while at slow speeds under very light acceleration" that confused my widdle bwain.
Thanks for the info & your willingness in making the effort to share good info, people. Much appreciated.
.
'Twas the "...while at slow speeds under very light acceleration" that confused my widdle bwain.
Thanks for the info & your willingness in making the effort to share good info, people. Much appreciated.
.
sailquik
Well-known member
Hi Bob,
How many RPM's does this happen at?
How much LOD on the ScanGaugeII?
What gear is the NCV3 in when it seems like it's in "too high a gear".
How about the geography..... is the van not accelerating on grades?
If the RPM's are < 2500... that could be your problem.
Or, it could be the EGR.
I'd opt for a change in driving style before looking at the EGR.
A few more RPM's will help to keep the LOD lower and may keep the
EGR functioning better.
Roger
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flman
Well-known member
It is just a thought for now, I never paid attention, I thought it was just how this thing operated?
Did not pay attention to RPMs but it is low.
No scangauge in use.
Not sure of the gear, I thought it was normal operation, never checked?
It is usually a grade that puts the van in a lagging situation, once again, I never made nothing of it other then normal operation.
Most likely the RPMs are low, I pretty much drove inline diesels for the past 10 years, now with a V I guess I need to put my foot into it more?
When I get back to work, I will follow your recommendations and see what happens
cedarsanctum
re: Member
Occasionally on hills and under very light load mine has been slow to downshift and seems to be lugging the engine slightly. After manually downshifting a few times, it sometimes seems to learn how to do it, until you restart. Lately i just step on the throttle enough to downshift it and accept that the tranny is slow sometimes.
I have also found the best cure is to turn up the music and ignore it, but that's just my opinion.
Jef
I have also found the best cure is to turn up the music and ignore it, but that's just my opinion.
Jef
flman
Well-known member
Seems it was just me, I have a Jeep Liberty CRD with a Hot tune in the ECM, and a TCM tune as well, and you can drive that thing like you have an egg under the pedal and get good response in any driving condition. So I guess I need to stimulate the skinny pedal more on the NCV3?