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Topic: Heat build up in rear of coach when traveling (Read 1056 times) previous topic - next topic

Heat build up in rear of coach when traveling

We took our first long trip in our 2007 Nimbus 336 Monday and Tuesday covering over 500 miles. The heat building up the bedroom which covers the Cummings diesel engine was almost unbearable. I turned the generator on to allow me to run the rear A/C unit to try and off set the heat.

What do most of you do to try and off set the heat build up in the rear of the coach? Is there a shield that could be placed under the bed to reflect some of the heat downward and away from the interior of the coach?
Wife Sue. Pets rescue: Suzie, Hobo, Peaches and Izzie the cat.
Rainbow bridge; Bart, Levi, Charlie, Old Fella, Mama
2007 Nimbus 336 Foretravel motor home

Re: Heat build up in rear of coach when traveling

Reply #1 –
I am sure the Nimbus has insulation between the engine and the bedroom.  It's possible that it has deteriorated and does not work as well as when it was new.  My bedroom will get hot after a long day of driving, although it does not get as hot as it used too since I replaced the insulation.  Running the generator and AC unit is about the only way to keep the bedroom cool when it's hot outside.
Jerry Whiteaker former owner 96 U270  36' #4831 Austin,TX-Owner Mods LCD TV w/front cabinet rebuild - LCD TV bedroom - Dual Central AC, either can cool coach w 30 amp - Skylights at roof AC openings - Drop ceiling for ducting of AC - Shower skylight white gelcoat/wood/epoxy frame - Air Springs/Shocks replaced - 2014 CRV - 8K Home Solar - Chevy Volt

Re: Heat build up in rear of coach when traveling

Reply #2 –
Mine only seems to warm the area up after I stop driving. When moving, I guess the airflow from moving forward and the radiator fans keeps it cooler.
1998 U270 34'

Re: Heat build up in rear of coach when traveling

Reply #3 –
Your coach is a lot newer than mine and it does get warm. Make sure the bed sits firmly down on its frame. And then examine the insulation in the engine compartment. Some may be missing. There are lots of products to reinsulate if you have to. 
1995 U320 40', 2013 chevy sonic toad, my real love are corvettes have owned 30

Re: Heat build up in rear of coach when traveling

Reply #4 –
We had the same heat problem in our 2003 GV320. Replacing the original muffler with a Magnaflo resonator eliminated the problem.

I don't know if your Nimbus has the same style of muffler, but if it does, that would be a good place to start.

Good luck!
2003 GV320 4010

Re: Heat build up in rear of coach when traveling

Reply #5 –
Of course we have a older 1997 U295, owned since 2001, and live in Texas. I have only had one time where I felt the heat from the engine warmed up the bedroom. We were on a trip back home from El Paso, while the generator was broken. We spent part of the night at a truck stop and ended up sleeping in the front because the back bedroom was warmer then the front.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Heat build up in rear of coach when traveling

Reply #6 –
As soon as we park I raise the bed and set a box fan blowing back over the engine, plug into the engine heater receptical.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Heat build up in rear of coach when traveling

Reply #7 –
Either the insulation around the engine compartment or on the bottom of the bed board or the seal around the bed board is most likely faulty. The only other suggestion would be to use a foam mattress on the bed if that is not what's in your coach now. A foam mattress provides a great deal more insulation than does a innerspring mattress.

Our old engine doesn't heat our bedroom even in 100 degree temps. I sometimes sleep on the bed while Peggy is driving and can feel no excessive heat. However I'm pretty sure the dash air units in the old Grand Villas are more effective than in the newer models.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Heat build up in rear of coach when traveling

Reply #8 –
I think that there are APPLES and ORANGES in the 2007 Nimbus question and the pre 2004 FT owner's answers:
There have been three major levels of EPA compliance for Diesel engines.
1. 2004; enhanced electronic controls & many engines added EGR systems.
2. 2007; Particulate systems added; slobber tube eliminated, and ULSD mandated.
3. 2010; Second level of NOX control kicked in which was met primarily by the DEF systems. Navistar medium duty engines used an enhanced EGR.

These dates are when the engine was built. FOT, like other builders, stock piled engines ahead of the dates and built coaches for a considerable period with engines built before the latest level. Most '07 coaches were built with no particulate filters and most '10 coaches with no DEF.
It would help to know what the Nimbus has for emissions control systems, but know that ANY of these iterations represent dramatically increased heat loads in the engine room.  Straight through mufflers are not an option.  The quality and quantity of insulation had to change dramatically along with the heat loads.
Neal
The selected media item is not currently available.
Neal (& Brenda) Pillsbury
'02 U320 SPEC, 4200, DGFE, Build #5984
'04 Gold Wing
'07 Featherlite 24'
'14 Jeep Grand Cherokee Summit
MC #14494
Exeter, NH & LaBelle FL
Quality makes the Heart Soar long after Price is Forgotten

Re: Heat build up in rear of coach when traveling

Reply #9 –
Quote from: Neal Pillsbury –
I think that there are APPLES and ORANGES in the 2007 Nimbus question and the pre 2004 FT owner's answers:
There have been three major levels of EPA compliance for Diesel engines.
1. 2004; enhanced electronic controls & many engines added EGR systems.
2. 2007; Particulate systems added; slobber tube eliminated, and ULSD mandated.
3. 2010; Second level of NOX control kicked in which was met primarily by the DEF systems. Navistar medium duty engines used an enhanced EGR.

These dates are when the engine was built. FOT, like other builders, stock piled engines ahead of the dates and built coaches for a considerable period with engines built before the latest level. Most '07 coaches were built with no particulate filters and most '10 coaches with no DEF.
It would help to know what the Nimbus has for emissions control systems, but know that ANY of these iterations represent dramatically increased heat loads in the engine room.  Straight through mufflers are not an option.  The quality and quantity of insulation had to change dramatically along with the heat loads.
Neal

Great and well researched information Neal as usual. But wouldn't you agree that heat levels as described would indicate a problem with either the seal or the insulation in the engine compartment rather than the standard for a Foretravel?
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Heat build up in rear of coach when traveling

Reply #10 –
Kent,
I'm not sure how well FT anticipated and designed around the additional heat burdens. I have heard several post-2004 owners discuss EPA compliance heat related, engine efficiency and engine component heat related failure issues.  Those discussions led me to an appreciation of why there is such a robust market for "gliders" (new OTR tractors w/o engines, in which the buyer installs his own rebuilt [pre-2004] engine, to circumvent the EPA emission control systems problems).  Not the least of those problems include extreme engine heat, power reduction burdens (robbed by the emissions control sytems) , turbo/exhaust valve/manifold/extreme heat failures, regeneration issues, DEF issues, and so forth.
So Kent, I'm just saying that the 2007 Nimbus may have some heat burdens that we pre-2004 coach owners don't have much experience with.  I for one am quite happy to have been able to find what I wanted in a FT and successfully avoid those EPA emission system challenges.
Neal
The selected media item is not currently available.
Neal (& Brenda) Pillsbury
'02 U320 SPEC, 4200, DGFE, Build #5984
'04 Gold Wing
'07 Featherlite 24'
'14 Jeep Grand Cherokee Summit
MC #14494
Exeter, NH & LaBelle FL
Quality makes the Heart Soar long after Price is Forgotten

Re: Heat build up in rear of coach when traveling

Reply #11 –
There are several later model Nimbus and Phenix owners on the Forum.  Are any of them experiencing the same issues?  Is it a common problem or one just for this coach?
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Heat build up in rear of coach when traveling

Reply #12 –
I have a friend that does not have a Foretravel and he is on his third new coach since 2013. All he did on the 2013 & 2014 was bitch about how hot the bathroom was after they made a trip and they had to keep the AC on to cool the room. He also said the title floor was so hot they could not walk on it barefoot. So I guess that problem is not just to this Foretravel.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Heat build up in rear of coach when traveling

Reply #13 –
Looks like FTs from 90s all of a sudden become even more valuable.
It is so sad that all these restrictions added on to these great engines to keep our environment clean are not engineered correctly. 
I guess it is not that much of a problem for transportation trucks / front mounted engines but the issue is more for the pushers.
Former 2003 GV U295 (6230) (2015 - 2025)
Former 94 GV U225 (2013-2016)

Re: Heat build up in rear of coach when traveling

Reply #14 –

Since my FT and yours have different engines and likely different types of engine compartment insulation, I don't know of how much use this will be to you but on the recommendation of some people on the forum I covered my old disintegrating insulation with a foil faced insulation

Amazon.com: Thermo-Tec 14125 48" X 72" Two Sided Thermo Guard Flame Retardant...

Prior to installing it, the bed would be too warm to sleep in after driving all day.  After installation, the bed was fine and there was no excessive heat buildup in the bedroom.  Since the insulation is only about 1/4" thick, it would seem that the reflective foil face on it is what does the majority of the work.  There should be a few posts on the forum about it if you search.

You could also look into wrapping your exhaust manifold, turbo and downpipe to reduce engine bay heat.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Robert
Build # 5304
1998 34' U270 Cummins 6CTA8.3

Re: Heat build up in rear of coach when traveling

Reply #15 –
tile floor heated? Usually are with the newer coaches...
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: Heat build up in rear of coach when traveling

Reply #16 –
My 40' 2008 with 600ISX can get warm after a all day trip.  However it is not unbearable.  I think a lot has to do with the bed configuration.  Ours is East to West.  One of our previous Foretravel's had North south.  It was hotter in that configuration as more of the bed was over the engine.

Re: Heat build up in rear of coach when traveling

Reply #17 –
Resonator & wrap turbo reduces heat a lot.