The overheating problem might be your viscous motor (highspeed fan motor that kicks on when your temp exceeds 200 degrees, it sounds like a jet engine when it's on)...I had it replaced when my rig overheated on climbs and it fixed the problem.
We would hear that fan kick on at odd times, I remember reading that someone had a problem with a fan, maybe it was you, we are taking the big beast into International, overheating problem, fuel tank issue, and the interior gauge located at the center of the roof which shows outside temp and direction seems to be malfunctioning, never had the right temp the whole trip.
Also, I forget to mention, something is really drawing the electricity down in the coach and ultimately the truck. We noticed that if we didn't run the generator first thing in the morning for several hours we would be dead. Go to bed at night full battery power, wake up battery at 1/3, couldn't even get the bed to fold up in the back. The only thing that was on was the heaters and water pump. If we left it without starting the generator it zapped the coach batteries and would start draining the truck batteries. We experienced this problem in our driveway at home before the trip began and called our dealer, we walked through the coach and systematically shut everything down including shutting down the whole coach with the electrical shut off valve. We left it alone for 24 hours, dead as a door nail, all four batteries. This will have to be checked out by Gulfstream. Anyone else have this issue?
2008 Conquest Super Nova 6400
2008 Pace 28' enclosed trailer
Earlier on this thread, there was a question about the amount of usable fuel that could be extracted from the 140 gallon tanks on the SuperNova. I just got mine back from International and they installed longer pickup tubes in my tanks. It seems the tubes that came from the factory were too short. I will not know how much more fuel I can get out of the tanks until my next trip which is scheduled from Texas to southeast Florida in early February. I will report back then on my findings.
I am curious about the motor in the 6400. We are also looking at this rig for our family. But we need it to tow round 10k. The dealer said it is rated at 15k towing, but I don't believe him. I had a F250 with the same 6.0 liter Diesel and it was ok, but nothing compared to the Duramax in my current 2007 truck. I cannot imagine that the 6.0 liter has the grunt to push this motorhome and pull 15k!! The dealer told me that it was governed at 75mph, which makes me think they lowered the gearing significantly to get the power required. That works in most situations...as long as you don't mind the motor spinning like crazy.
2007 GMC 3500 4x4 Dually, LBZ Duramax, 6sp Alison
pulling:
2007 Sandpiper QBQ, four bunks and four slides!
pulling:
20ft. Utility trailer holding
Polaris Ranger XP
Polaris Sportsman 800
Kazuma 110
Kazuma 50
The original gearing on the SuperNova when they were first built was 617 and it has a 3200 rpm governor. When I had those gears in my coach, 75 mph was top speed. I have since changed to 529 and top speed is 86 at 3200 rpms. I have read that Gulf Stream now puts the 529 in all new production coaches. My coach weighs 21700 full of fuel, gear, water, and wife and I. The GCWR is 33000#. I could tow a maximum of 11300#. I am quite sure the 6400 is heavier than the 6331 so, no, you cannot tow 15000# without going over the GCWR of the coach. As far as the engine goes, it is not the same as was in the Ford pickups. International has their own unique fuel and electronic systems. I have found the engine to actually be better than the Duramax I had in my last coach but I attribute a lot of that to the Allison 2500MH in the International over the Allison 1000 I had in the Duramax. I have not driven a 6400 but several on this forum say they have plenty of towing power.
Texas TC wrote: Earlier on this thread, there was a question about the amount of usable fuel that could be extracted from the 140 gallon tanks on the SuperNova. I just got mine back from International and they installed longer pickup tubes in my tanks. It seems the tubes that came from the factory were too short. I will not know how much more fuel I can get out of the tanks until my next trip which is scheduled from Texas to southeast Florida in early February. I will report back then on my findings.
Very interested to find out if this fixes the fuel issue. When my rig gets out of the shop I'm taking it to International. Thanks TC.
2008 Super Nova 6400
2007 Dodge Ram Mega Cab
2006 Mercedes E350 Sport
2005 Mercedes G500
1996 Porsche 911 Targa
T0951 wrote: We are back from our trip from Chicago to San Diego along Route 66. The Supernova 6400 was great. Plenty of room for our family of 6. We cooked, watched videos, played WII etc... The ride was pretty smooth, depending on the highway it could be rather bumpy, but that is to be expected. On the topic of fuel, we could not get the fuel down either, the most we were able to put in was 96 gallons and believe me that was a pain, the generator cuts out at 1/4 of a tank and it was just too much to listen to the kids complain that the generator wasn't working and they were "bored". So we ran it down twice to the red light and 96 gallons was the most it would take. Did anyone find out anything on this topic. Also the 6400 did not like the inclines! We were traveling with a 28 ft. enclosed trailer, it was not filled to capacity, and not only did it bog down on the inclines but the engine would heat up to the point of the engine light coming on. We backed off after that and went from 60 to about 40 up most grades. Mind you as soon as we backed down the temp went down. We were disappointed in the lack of power on even some of the smallest grades. Tentsnomore I know you travel quite a bit through grades and travel with a trailer have you experienced anything like this? We will be looking for a chip, booster, whatever we can find that will give us more power. We had a few other issues, the wall slide was causing us a bit of a problem. When we first started out I noticed on the second night that on the bunks there are two fabric covered caps on each end of the bunks that run from the top of the slide to the bottom and are flush with the slide, when we were closing the slide the bottom of one of the them was rubbing on the carpet. By the third night it was coming away from the frame and really dragging on the carpet. We decided it needed to come off and without much effort we pulled it right off. It actually worked out well because if the slide was closed the kids could wiggle their way into the bunk to watch a movie or take a nap. We have to get the piece cut down and back up, it looks totally unfinished. The cold water pipe attached to the back bathroom sink was leaking and we didn't realize this until the carpet in the MB was wet. So we pulled out three rolls of soggy toilet paper that had been stored under the sink and were absorbing the water for a few days and tightened up the fitting and leaking stopped. Another problem, the levelers, sometimes they worked and sometimes they didn't, they would go down and not come up or they would not go down. We called our dealer and he faxed us directions on how to override the system, but it is still a problem we need to address. Otherwise the trip was wonderful, we were the only Supernova in the Anza Borrego Desert amoungst hundreds of various rigs, we had 10 people sleeping in it a couple of nights because my sister's carbon monoxide alarm was going off and she didn't trust her r.v., it wasn't a problem we used every bed double duty. We will keep you posted on any answers we find to our issues.
T0951-what was the culprit of your overheating issue?
Texas TC wrote: The original gearing on the SuperNova when they were first built was 617 and it has a 3200 rpm governor. When I had those gears in my coach, 75 mph was top speed. I have since changed to 529 and top speed is 86 at 3200 rpms. I have read that Gulf Stream now puts the 529 in all new production coaches. My coach weighs 21700 full of fuel, gear, water, and wife and I. The GCWR is 33000#. I could tow a maximum of 11300#. I am quite sure the 6400 is heavier than the 6331 so, no, you cannot tow 15000# without going over the GCWR of the coach. As far as the engine goes, it is not the same as was in the Ford pickups. International has their own unique fuel and electronic systems. I have found the engine to actually be better than the Duramax I had in my last coach but I attribute a lot of that to the Allison 2500MH in the International over the Allison 1000 I had in the Duramax. I have not driven a 6400 but several on this forum say they have plenty of towing power.
How do you know if the unit you are looking at to buy has the 617 or the 529 gears? Without actually driving it to record RPM vs MPH? Is there a certain build date or build sheet?
Call and have an International dealer run your VIN through their ISIS system. It will create a build sheet for the chassis and tell you everything that went in to that particular unit. I had this done for my International chassis as well as the Chevy Kodiak coach I owned before this one. The dealers are good about doing this for you especially if it is a dealer that might get your service business. It also makes a great reference sheet to add to your coach history file.
T0951 wrote: T0951-what was the culprit of your overheating issue?
She's in the shop now. I will let you know, I think you might be right though about that fan.
Curious about what you are having done to your SN6400 in the shop, can you update us on that?
Two repairs...when we purchased the coach it had a hair line crack in the fiberglass cab-over (about 3 inches long above the passenger door). GS is repairing and repainting. The second repair is on the hitch...it bent. On our way to AZ over the New Year holiday the hitch bent while towing our 8K lbs trailer??? The trailer tongue wieght is 7-900 lbs and the hitch is rated at 1,500 lbs. Thank God I have a great dealer...
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