Yellow Bullet Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
1,379 Posts
Discussion Starter #1
I have a 2008 Fleetwood with a Cummins 6.7 ISB. I started hearing a noise that sounds like the belt is squealing, but only when the engine retard is on. If I turn off the retard, the noise quits. Turn it back on, there it is again.


I don't hear it every time, but it seems to be getting more prevalent. I can't figure out how the serpentine belt would be squealing, but that's what it sounds like.

Any advice would be appreciated.
 

·
Registered
Joined
·
459 Posts
Some retarders are programmed to turn the fan on when the retarder activates (when the switch is on and you take your foot off the throttle). If its an exhaust restrictor type of retarder it might just make a whistling noise.
 

·
Registered
Joined
·
20,374 Posts
trans brake will cause the trans to downshift early causing rpms and engine load to increase which can cause a worn belt to squeal.
 

·
Registered
Joined
·
1,379 Posts
Discussion Starter #5
possible exhaust manifold gasket leak as well, or crack etc..

If it was an exhaust leak, wouldn't I hear it all the time? Not just when the retard is on?


Thanks for the replies. My old KW's fan would turn on when the brake was on. I don't know about the motorhome though. But, I'll definitely look into that.

again, thanks.
 

·
Registered
Joined
·
4,222 Posts
Tony if it's an exhaust brake it works by back pressure.

So a gasket leak would be most obvious while applying the brake.

Also have Mumau's check it out at the track ?
 

·
Registered
Joined
·
6,563 Posts
possible exhaust manifold gasket leak as well, or crack etc..
That was my first guess also.

Look for soot around all exhaust connections/flanges/etc.

Also, look closely at any flex joints/bellows for cracks.

Is the engine painted red or black? If it's red the soot should be easy to see. If it's black you might need to use an EVAP smoke machine and a little compressed air to see where it's leaking.
 
1 - 8 of 8 Posts
Top