8.1L in Winnebago Only Turns 3,000 RPM....

Capt Joe · 02-12-2008, 04:47 PM

We have a 2004 Winnebago Brave 32V with the W22 chassis, 8.1L/Allison with just over 6K miles. Had oil change with filters (oil and fuel)also changed today. It seemed to run fine on the way home (about 5 miles).
After I got home and parked it and noticed a bit of white exhaust coming from the right side exhaust (it was very damp weather and getting cooler). I increased the engine speed, in park, to see if the exhaust would clear (which it mostly did) but the engine would only turn up to 3000 RPM...exactly 3K and no more. Did it several more times and got the same result. Also seemed, from the drivers seat only as I was by myself, to have a little bit of flutter sound (or something like that) as the revs went thru about 2500and then the fluttering quit above that.
Any ideas what could be causing this 3000 RPM limit on the revs? How about the fluttering sound from the exhaust??? Something related to the oil change??? Or???

Any thoughts would be appreciated.

Capt Joe · 02-12-2008, 04:47 PM

We have a 2004 Winnebago Brave 32V with the W22 chassis, 8.1L/Allison with just over 6K miles. Had oil change with filters (oil and fuel)also changed today. It seemed to run fine on the way home (about 5 miles).
After I got home and parked it and noticed a bit of white exhaust coming from the right side exhaust (it was very damp weather and getting cooler). I increased the engine speed, in park, to see if the exhaust would clear (which it mostly did) but the engine would only turn up to 3000 RPM...exactly 3K and no more. Did it several more times and got the same result. Also seemed, from the drivers seat only as I was by myself, to have a little bit of flutter sound (or something like that) as the revs went thru about 2500and then the fluttering quit above that.
Any ideas what could be causing this 3000 RPM limit on the revs? How about the fluttering sound from the exhaust??? Something related to the oil change??? Or???

Any thoughts would be appreciated.

Tenn.Vol. · 02-12-2008, 05:25 PM

Capt. "They all do that"!!!!And no I am not a Dealer, it programed in the ECM.
And I found out in 02, that the top speed was 75 or 77MPH. Now that is an
uneasy felling as I was dropping out of the rockies and ran out of pedal.
I had the GOVERNOR removed, and now let my toad gov. my speed!!!Tenn.

Capt Joe · 02-13-2008, 04:54 AM

Tenn.Vol,

Thanks for the info. on the speed limitations.

I have been thru the Operator's Manual and the Workhorse Owner's Manual but haven't run across this feature. While I'm not a 'hot rodder' by any means, it would appear that by having this 3000 RPM limitation, you are not able to get the max power out of the 8.1 (340hp @ 4200 RPM and 455 lb-ft @ 3200 RPM).

Might need a few more ponies on a climb at altitude when towing a toad?

Any thoughts?

FrankO · 02-13-2008, 05:04 AM

If there is a limiter on the RPMs it is greater than 4600 as I have driven up numerous hills where the 8.1 downshifts and RPMs go over 4300. I usually back off a little but there seems to be no limit to that point.
Frank O.

Capt Joe · 02-13-2008, 05:12 AM

Thanks FrankO.
Just finished reading some old posts after searching for 8.1 3000RPM and saw where it is reported that the limiter to 3K is only in Park and Neutral. That is a good idea, just had me a bit worried as this is the first time I have had the RPMs up while in Park or Neutral....it's not something I would normally do.
Any other imput????
Thanks again,

Oemtech · 02-13-2008, 05:18 AM

3k rpm in park or neutral is programmed into the ECM as a safety factory. The 4.5k+/- rpm is max when in drive and is programmed into the ECM.

There is a speed limiter of 80 mph programmed into the ECM. I believe that the limited was dropped to 75 mph sometime in either 06 or 07.

j griff · 02-23-2008, 08:19 AM

Is this a great forum or what !! I just came in from "excersing" my W20 8.1 without getting out in the ice, snow and salt on the roads. After a suitable warm-up I "revved" the engine several times and it would not go over 3000rpm. Came in and did a "find" on rpm and sure enough got the expert answers. Thanks everyone.

Nonno · 02-24-2008, 01:22 PM

Capt Joe also asked <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Also seemed, from the drivers seat only as I was by myself, to have a little bit of flutter sound (or something like that) as the revs went thru about 2500and then the fluttering quit above that. </div></BLOCKQUOTE>

Any ideas about that. Sounds similar to what I have.