RV Trip Planning Discussions

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

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 03-10-2016, 02:47 PM   #1
Junior Member
 
Join Date: Dec 2011
Posts: 10
apparent heat related problem with engine and gen.

We have a 2003 National Dolphin 5355 with the Onan 5500 gen. We have had nothing but problems with the gen and Onan suggested buying a new one cause they can't figure out what is going on. The rig now has just quit while driving a couple of times now. We have recently been doing a lot of driving during very hot weather and the problem arises when it is very hot. It was over 100 in Portland Or. and the rig just quit while going very slow in heavy traffic (just what we wanted). I waited a few seconds and hit the ignition and off we went. Once we got moving it was fine. It also quit once pulling a hill going east out of Salt Lake City with the same re-start success. Many, many years ago I experience vapor lock on a car and this feels just like that, the engine just seems to run out of gas. We have never had a problem here in Seattle, only on the road. With temps in the 80s and even the 90s it seems ok, but hotter than that and going very slow it quits. In a 6000 mile trip to Florida and back it failed twice (described above). I'm beginning to suspect a similar problem with the generator. I can run it for hours in cooler weather and not have a problem even with a full load. Onan/Cummins ran it for three hours with both AC units going full blast and no problem. Sometimes it starts but begins to lop until it gets worse and quits. In Florida, with one ac unit going and it being in the 90s it quit and would not restart until the next day. It does this quite consistently except at the Onan/Cummings dealer. I suspect the gas line runs too close to something hot and a vapor lock occurs but can't prove it, any one have a similar problem??
__________________

HobieRV 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 03-10-2016, 02:57 PM   #2
Senior Member
 
Mr_D's Avatar
 
Country Coach Owners Club
Winnebago Owners Club
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 35,965
Portland OR and over 100°? Almost never happens so you got lucky!
__________________

__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 Jeep JKU
Mr_D is offline   Reply With Quote
Old 03-10-2016, 03:01 PM   #3
Registered User
 
Join Date: Nov 2005
Posts: 4,993
Might understand a vaor lock when driving but not while sitting, even in 100 degree weather. Not sure why but might consider a new gas cap--just guessing.
Old Scout is offline   Reply With Quote
Old 03-10-2016, 03:04 PM   #4
Senior Member
 
Monaco Owners Club
Join Date: Feb 2014
Location: Oshawa
Posts: 293
Quote:
Originally Posted by Hobierv2003 View Post
We have a 2003 National Dolphin 5355 with the Onan 5500 gen. We have had nothing but problems with the gen and Onan suggested buying a new one cause they can't figure out what is going on. The rig now has just quit while driving a couple of times now. We have recently been doing a lot of driving during very hot weather and the problem arises when it is very hot. It was over 100 in Portland Or. and the rig just quit while going very slow in heavy traffic (just what we wanted). I waited a few seconds and hit the ignition and off we went. Once we got moving it was fine. It also quit once pulling a hill going east out of Salt Lake City with the same re-start success. Many, many years ago I experience vapor lock on a car and this feels just like that, the engine just seems to run out of gas. We have never had a problem here in Seattle, only on the road. With temps in the 80s and even the 90s it seems ok, but hotter than that and going very slow it quits. In a 6000 mile trip to Florida and back it failed twice (described above). I'm beginning to suspect a similar problem with the generator. I can run it for hours in cooler weather and not have a problem even with a full load. Onan/Cummins ran it for three hours with both AC units going full blast and no problem. Sometimes it starts but begins to lop until it gets worse and quits. In Florida, with one ac unit going and it being in the 90s it quit and would not restart until the next day. It does this quite consistently except at the Onan/Cummings dealer. I suspect the gas line runs too close to something hot and a vapor lock occurs but can't prove it, any one have a similar problem??
When the Cummins people tested it did they run it on road or just let it sit idling. A diesel runs cold when idling which is why they say to "exercise" them you should take them out on the road. Is it a front engine? Did your fuel sit for a long time at any point before this happened?
FixerCQI is offline   Reply With Quote
Old 03-11-2016, 10:00 AM   #5
Junior Member
 
Join Date: Dec 2011
Posts: 10
The Dolphin is a gas version.

The gen and engine share the same supply of fuel and most all of the failures occurred when standing still or moving very slow in heavy traffic. I was trying to find a place to put the remote sending unit for the "weather station's" temperature. It has batteries and I wanted a place to be out of the Sun and easy to get to. So I put it back in the propane tank bay which is not totally enclosed but it the shade. Interesting enough it doesn't work well in sensing outside temps while moving but does work well in telling the amount of heat coming from the roadway in addition to ambient temps. We were seeing 125-130 at the time the RV quit. The sensor is near the gas tank and opposite site from the gen.
HobieRV is offline   Reply With Quote
Old 03-11-2016, 10:01 AM   #6
Junior Member
 
Join Date: Dec 2011
Posts: 10
and it was new gas
HobieRV is offline   Reply With Quote
Old 03-11-2016, 11:34 AM   #7
Senior Member
 
chboone's Avatar


 
National RV Owners Club
Ford Super Duty Owner
Join Date: Sep 2010
Location: Horse Town USA, CA.
Posts: 3,225
HobieRv,
I had a similar problem with my Generac 5500 could sit all day in hot weather over 95°F with both AC's running it would not shutdown on high temperature. Going down the road it would shutdown in 80° degree weather. What I found was the problem, the full length rubber mud flap/stone guard across the back was not allowing the hot air/exhaust gasses from generator to exit and the generator was recycling the hot air. I made up a forward facing scoop for the generator to pickup cooler air. Never had a problem again with shutting down on high temperature going down the road even in the hot summer temperatures. Don't know what's going on with your engine. Have you had anyone check for stored codes? You may need to hookup a code reader the will read real time that can record at the same time and drive it in the same conditions it has failed on you.
__________________
1999 35 ft. Dolphin 5350, F53, Banks System, 5 Stars Tune, Air Lift Air Bags, Koni Shocks, Blue OX TruCenter, TigerTrak track bars F&R, Roadmaster 1-3/4" rear auxiliary sway bar, 2004 F450 Lariat 6.0 Diesel Crew Cab DRW, 4X4, B&W Custom Truck Bed, GVWR 15,000, Front GAWR 6,000, Rear GAWR 11,000, GCWR 26,000, 1994 36ft Avion 5er, GVWR 13,700
chboone is offline   Reply With Quote
Old 03-11-2016, 09:45 PM   #8
Senior Member
 
Belgian's Avatar
 
National RV Owners Club
Join Date: Jun 2006
Location: Manhattan Beach, CA
Posts: 650
I think you have two gas lines, one for the NH engine and another for the Gen. Have you changed the fuel filter for the MH engine which is mounted inside the frame? Mine had a bad gas hose from the tank to the Gen, it had small cracks from age. Onan gens are very sensitive to oil level. Remove the dipstick, wipe and just set it inside the hole without screwing it in and read the oil level. If it's low it may shut off due to low oil psi. Check all your ground connections. The main one for both batteries just behind the battery box, one from the engine to the frame, one behind the right front tire and a little forward, one behind the instrument cluster and two at the Gen. One from the gen to the frame and one to the MH frame. You may have more grounds.

Good Luck!

on Edit; the fuel pump for the Gen is a problems sometimes also. I replaced two before I found a good one. Both were from the dealer but he said they had problems with fuel pumps also.
__________________

__________________
Steve & Jeri
2004 Dolphin 5342
2000 Jeep Cherokee 4X4
Belgian is offline   Reply With Quote
Reply

Tags
engine, heat



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
No Apparent Lockup With MT 643 philipswanso Allison Transmission Forum 8 03-23-2016 08:46 AM
Check Engine light on 8.1 Workhorse no apparent reason Auzboy Workhorse and Chevrolet Chassis Motorhome Forum 31 09-30-2014 11:59 PM
Yet another problem surfaced AC related! Jchet Class A Motorhome Discussions 5 09-04-2012 12:43 PM
Engine Gen warning lite on when running gen set Gumby Monaco Owner's Forum 11 06-01-2012 08:15 AM
noisy woofer when no apparent volume is turned on aaamarine Class A Motorhome Discussions 1 05-10-2012 11:48 AM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:12 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.