Free 7 Day Trial RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Monaco Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 11-30-2021, 03:44 PM   #1
Member
 
jimsimrv's Avatar
 
Join Date: Jan 2019
Location: DFW
Posts: 65
Low turbo boost

I've been slowly migrating to South Padre Island for the winter months, and I'm almost there (200 miles out.) Everything has been working just fine until today's drive. I noticed the coach was very sluggish on hills and not maintaining 65mph on the slightest of inclines...

I started to watch the turbo boost psi while under load, 7 psi was the highest I saw it go. Normally, I'll see 21 or 22 when under a heavy load.

I found a post over in Country Coach forum with the exact same symptoms on the same motor I have (CAT C12). That turned out to be the waste gate stuck open.

I don't see anything amiss on my initial visual inspection, but I'm waiting for it to cool down before I take a closer look.

Lucky I'm about as flat as you can get for the last 200 miles, but I'm wanting to know if I risk any further damage to anything driving it in this condition?
__________________
04 Beaver Patriot Thunder, 505 HP C12, 41 foot, tag, Allison 4000
jimsimrv is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 11-30-2021, 03:56 PM   #2
Senior Member
 
RamiDav's Avatar
 
Join Date: Jan 2016
Posts: 1,839
Look down this page and there is a window titled similar threads.
You may find help there.

Many times a sudden drop in boost is simply a hose blown loose at the turbo or intercooler.

Ray 03 Windsor
RamiDav is offline   Reply With Quote
Old 11-30-2021, 04:06 PM   #3
Member
 
Join Date: Nov 2021
Posts: 62
Boost hose

Yes usually makes a vacuum type sound when into boost with a blown hose , make sure simple check also air cleaner clean ..
no boost can also mean no fuel , need fuel to make boost fuel filters are easy ..
Sspdiesel is offline   Reply With Quote
Old 11-30-2021, 04:13 PM   #4
Senior Member
 
Join Date: Jul 2014
Posts: 29,430
Go with fuel filters first if they haven't been replaced recently.
twinboat is offline   Reply With Quote
Old 11-30-2021, 04:22 PM   #5
Member
 
jimsimrv's Avatar
 
Join Date: Jan 2019
Location: DFW
Posts: 65
Both fuel filters were replaced in Colorado before I left. I can change them againA, but I procrastinated after service a couple months ago and I'm sad to say that I don't have them on hand at the moment.

Aside from crappy performance, is it OK to drive down to my spot tomorrow and deal with it there?

Also, is there a way I can check if its any better without driving it and figuring out some sort of hill to go up?
__________________
04 Beaver Patriot Thunder, 505 HP C12, 41 foot, tag, Allison 4000
jimsimrv is offline   Reply With Quote
Old 11-30-2021, 06:33 PM   #6
Member
 
Join Date: Nov 2021
Posts: 62
Fuel filters

Dirty fuel filters ( fuel restriction ) is a bad thing c-12 has unit injectors there about 800 each no fuel they run hot and seize the plunger to the barrel .
If itís a e engines there more .
I can say this so many times , before major engine issues diesel show a sign a symptom before major engine parts fails . Donít drive something with a issue ..
CAt filters can be found at any truck stop , they can quick change them .

Best way is to just get in and look at things you will see a failed hose or broken clamp if you look .

I personally rebuild tons of c12 in boats there was a class action law suit with a c12 , salt water after-cooler issue . Trucks donít have them ..

We , use to do stall test on the nyc buses when we could not road test them.
We would put it in gear hold the brake and throttle it up .. we even block the wheels , the boost will come up fast ..itís how rods with diesel take off bring boost up first ..in the old days it was call power braking .
Sspdiesel is offline   Reply With Quote
Old 11-30-2021, 06:44 PM   #7
Senior Member
 
Join Date: Jul 2017
Location: Blue Springs, MO
Posts: 646
Perhaps a crack leak in your charge air cooler or perhaps your engine is de-rated due to another issue? My Cummins de-rates to around 7 psi but normal is 37 psi.
__________________
2009 Country Coach Veranda 400, ISM 500
2019 Lincoln Nautilus Toad
2020 Lectric XP E-bike (Hybrid)
BonS is offline   Reply With Quote
Old 11-30-2021, 07:40 PM   #8
Senior Member
 
jdw1's Avatar
 
Monaco Owners Club
Join Date: Jul 2018
Location: Minnesota
Posts: 148
Did you notice this all of a sudden going down the road or after a stop, that might indicate whatís going on!

If you have a boost leak your exhaust will run pretty hot because itís not getting enough air!

I would think it would be best to resolve the issue before you arrive at your destination, imo!

I would check your aftercooler tubes for leaks, check the boots from the tubes to the aftercooler in case one has broke or a boot tore, check all the clamps on the charged air system, itís possible itís something very simple. If it was mine Iíd be headed for a Cat dealer or someone that understands these systems, Iím fortunate that I understand it, Iíd wouldnít drive it any further than I had to!

Itís possible to have a split in the aftercooler too!

Jmo
__________________
05 Dynasty Platinum IV ISL 400
Itís the journey not the destination!
jdw1 is offline   Reply With Quote
Old 12-01-2021, 09:24 AM   #9
Member
 
jimsimrv's Avatar
 
Join Date: Jan 2019
Location: DFW
Posts: 65
I found the exhaust pipe where it connects to exhaust manifold with 4 nuts. There is a metal gasket hanging out and the top two nuts are missing.

I went thru my nuts and bolts and don't have anything that matches...

I'm going to limp on down the road and stop at the first truck stop to see if they can help me with it.

Thanks everyone for your suggestions/guidance on this.
__________________
04 Beaver Patriot Thunder, 505 HP C12, 41 foot, tag, Allison 4000
jimsimrv is offline   Reply With Quote
Old 12-01-2021, 09:41 AM   #10
Senior Member


 
Join Date: Aug 2021
Location: Fitchburg, WI
Posts: 132
Looks like you found the problem and it will be a cheap fix. Good for you.
__________________
Orrin
2002 HR Ambassador
Fitchburg, WI
Orrin is offline   Reply With Quote
Old 12-01-2021, 11:14 AM   #11
Senior Member
 
garage man's Avatar
 
Monaco Owners Club
Join Date: Nov 2020
Location: Rogue Valley, Southern Oregon
Posts: 173

How often do we get to say "a cheap fix".
This forum is great!
__________________
Hitting the road from Oregon
1993 Monaco Crown Royal Signature 40'
The "Gentle Giant"
garage man is offline   Reply With Quote
Old 12-01-2021, 05:26 PM   #12
Member
 
Join Date: Nov 2021
Posts: 62
Exhaust

Keep in mind that might be the cause but what did it do to the engine that made it low boost .
Exhaust leak in engine compartment
One air cleaner full of soot from exhaust
Charge air cooler full of soot from exhaust leak
Look deeper ..
It would have to be a exhaust manifold , or turbo mounting gasket failure to
Cause low boost .
Sspdiesel is offline   Reply With Quote
Old 12-01-2021, 06:11 PM   #13
Senior Member
 
jdw1's Avatar
 
Monaco Owners Club
Join Date: Jul 2018
Location: Minnesota
Posts: 148
Just make sure you get the proper nuts, those exhaust manifold nuts are a special material, thereíre not hardware store nuts! FYI.

Also fwiw, a person should be able to actually hear a manifold leak just standing at the back of your coach listening!
__________________
05 Dynasty Platinum IV ISL 400
Itís the journey not the destination!
jdw1 is offline   Reply With Quote
Old 12-01-2021, 06:31 PM   #14
Junior Member
 
Join Date: Nov 2021
Posts: 21
Good catch, if the exhaust is able to go somewhere other than through the turbo it will certainly decrease boost.
Tooltime2 is offline   Reply With Quote
Reply

Tags
turbo, turbo boost



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Low Turbo Boost and Exhaust brake performance Rburian Cummins Engines 7 04-03-2017 07:15 PM
C7: Phantom "Low Boost" and "No Boost" Codes ProjectPro Caterpillar Engine Forum 6 12-22-2016 01:20 PM
Low boost, cracked exhaust manifold , intercooler leak, turbo joslawrence Monaco Owner's Forum 12 08-18-2016 07:35 AM
Turbo Boost What is the Maximum Boost that a 5.9, 275HP shogun1940 Cummins Engines 10 11-30-2014 08:47 PM
Turbo boost suddenly a bit low Papa_Jim Monaco Owner's Forum 15 10-03-2013 09:32 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 12:28 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.