Thread Tools Display Modes
Old 07-06-2015, 10:15 PM   #11
Senior Member
Join Date: Nov 2014
Posts: 1,073
Fiel leak? A dealer cant figure it out??? Sounds like a really dumb or lazy dealer. Find another dealer with a knowledgable diesel tech

donniedu is online now   Reply With Quote
Old 07-06-2015, 10:16 PM   #12
Junior Member
Join Date: Jul 2015
Posts: 4
Thanks toslow for the Tech tip - will take it with us to a diesel mechanic.

Grayfox - did you mean Onstar or Onstar?

bhecko is offline   Reply With Quote
Old 07-06-2015, 10:44 PM   #13
Senior Member
DaveSchwartz's Avatar
Join Date: May 2014
Location: Waterloo Region
Posts: 723
How long is it since you changed the fuel filter? I was a bad boy and let it go too long once and it would go into limp mode unless I was very lightfooted. The code was something about the measured fuel pressure being too far below that commanded by the ECU. A fresh filter fixed it up. The next most likely is the fuel pressure relief valve (FPRV). You don't want it to be the high pressure fuel pump.
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam

Self restraint is for the young. I'm old and want it NOW!
DaveSchwartz is offline   Reply With Quote
Old 07-07-2015, 11:17 AM   #14
Claude002's Avatar
Join Date: Jul 2013
Location: Lac Des Plages QUEBEC
Posts: 72
Hi just bought the same engine Diesel 2015 one week ago and was told by a GM employe to buy an extra filter if I do a lot of dusty highway, because what you are saying can happen, maybe its a solution???(i'm no mecanic) but wanted to help, good luck.
Claude002 is offline   Reply With Quote
Old 07-07-2015, 11:21 AM   #15
Senior Member
Crusadernoob's Avatar
Join Date: Dec 2013
Posts: 661
Sounds like you are sucking air into the fuel supply as when you prime it you regain power. I have seen a lot of fuel filter heads, some fuel hoses. You can get the dtc's and PM me but more than likely it sounds like an air issue as you can reprint it. Try to prime it until it is tight and some times you can spot a leaking fuel filter head, water sensor.
2006 2500HD CCSB 2WD 2014 Crusader 285RET
Nights camped in 2013 - not enough!, 2014 37, 2015 40, 2016 39, 2017 38, 2018 14
Crusadernoob is offline   Reply With Quote
Old 07-07-2015, 11:28 AM   #16
Junior Member
Join Date: Mar 2015
Posts: 17
The duramax engine is designed to protect itself and the transmission. I had a similar issue by not putting the truck in "Tow" mode and going happily down the highway until the transmission went into limp mode. The duramax is also designed to reduce engine power when it gets hot. It won't send a message to the DIC if you're coolant mixture isn't at a 50/50 mix. If there were any codes thrown you might want to see what they are and maybe that'll give you and idea where to start.
msrafd is offline   Reply With Quote
Old 07-07-2015, 11:34 AM   #17
Junior Member
Join Date: Mar 2013
Posts: 24
Throttle position sensor. Needs to be replaced and is a "skeleton in the closet" issue for GM trucks. Google it. Happened to me
Nastyfoot is offline   Reply With Quote
Old 07-07-2015, 11:36 AM   #18
Senior Member
Join Date: Nov 2014
Posts: 140
Sounds like injectors leaking. Is your oil level over full and smells like diesel fuel? Early Durmax had injector leakage issues. Also follow diagnosis charts for dtcs. May have fuel tank sock ( filter) restrictions. You shutting off truck reset the reduced power mode.. take it to qualified mechanic. Or you will spend more money on someone learning
jimmyt11664 is offline   Reply With Quote
Old 07-07-2015, 11:44 AM   #19
Junior Member
Join Date: Jul 2015
Posts: 1
Duramax problems

You have a couple of possibilities. A hairline crack in your filter housing, a weak pickup pump, or a weak CP3 pump. I replaced my filter with the FAAS double filter system it helped some but ended up replacing my CP3 [injector pump]. It worked fine under normal conditions but when under a load it would code and go into limp mode. If you shut it off and pump the filter full and wait for I think for 2 minutes it would reset and work ok for a little while but got progressively worse. If your in Pa or near there are a couple of guys here that only work on the Duramax they are very knowledgeable. Let me know and I can hook you up with him.

Good Luck
RSHAWVER is offline   Reply With Quote
Old 07-07-2015, 11:57 AM   #20
Join Date: Mar 2015
Location: Jacksonville
Posts: 32
I had a 5500 Kodiac that did the very same thing, I would shut down under load and higher speeds. I got rid of it. Could not fix the problem.

Chevy and GMC Duramax Diesel Forum

This web site will help list about 30 possible fixes. Good luck.

BRUCEANDCYNDI is offline   Reply With Quote

diesel, power

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

» Featured Campgrounds

Reviews provided by is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 12:36 PM.