Caution about the Sprinter.

Allenj,
your info is correct, other than the weight, which, as far as we know, is at 4535, take or leave a few pounds; still a lot heavier than your Liberty. We also added soundproofing. We do not know how much weight that added, but we know it was substantial. So we realize now that we were on the hairy edge; still, the seriousness of the symptoms certainly took us by surprise. We have taken the Sprinter in today, we will know tomorrow where we stand. Either way, I think there is going to be a new vehicle in our future. Unfortunately, that cannot happen until at least next year. After eliminating everything we could, we are still at around 4400 lb of TM+cargo, pretty high. One of the puzzling things is that, if we were overloaded, we would have expected to have problem braking, but that was not the case. Braking was OK, in fact not significantly different than without the trailer, even going down the hill (The same hill on which we could not go up).
Well, we learned a valuable lesson. Cannot be naive about how much all our stuff really weighs.
So, depending on the answer we get tomorrow, we will leave for an all-flat terrain trip, or will scrap this particular trip altogether. Sigh!

I took a guess at the specific model to research the weight, it was probably an extended bed version that I picked on Edmunds.com (the 140 WB).
Good luck!

[Mr. Adventure]

I certainly would have thought your Sprinter would be a good tow vehicle for a TrailManor. The first thing that comes to mind, is that heavy diesel trucks have to work pretty hard to get over the mountain and are hugely underpowered compared to what we're used to on four wheels for towing TM's. It's not that we couldn't get over the mountain in an RV with performance like a heavy truck, it's that we just wouldn't want to.

More to the point, towing isn't a black and white business. There are variables that make things a lot fuzzier than we'd like them to be.

Thanks for sharing your experience!

[Bill]

Originally Posted by Pierak706

One of the puzzling things is that, if we were overloaded, we would have expected to have problem braking, but that was not the case. Braking was OK, in fact not significantly different than without the trailer, even going down the hill

I think you should expect braking to be about the same. Remember that the trailer has its own brakes. In the ideal world, the trailer will stop itself, and do so in the same distance that it takes the truck stop itself - so you would experience no difference at all.

As always, the words "In the ideal world ..." deserve a lot of attention, because we don't drive in the ideal world. In the real world, the tow vehicle and the trailer each do most of their own braking, but you can never adjust things to make the braking effort perfectly equal. If the trailer doesn't brake quite hard enough, the tow vehicle has to take up the slack, and stopping distance becomes a bit longer. But just as important, when the trailer is pushing on the tow vehicle, it has a tendency to push the back of the tow vehicle to the side, which can result in loss of control. The tow vehicle's wheelbase determines its ability to resist this sideways pressure, and short-wheelbase vehicles are a bit scary for that reason.

Of course, if the trailer brakes fail, then you have the worst case. The truck must stop both itself and the trailer, and obviously the stopping distance will be a lot greater. More important, the tow vehicle's brakes have to be adequate to stop both vehicles without overheating and fading out, even if you happen to be on an extended downgrade. This is (or should be) an important consideration in choosing a tow vehicle. And at the same time that the tow vehicle is stopping both itself and trailer, it has to resist the jack-knife tendency of the completely unbraked trailer. This is a big deal! I've experienced partial brake failure on a 10% downgrade with twisty turns. It wasn't fun, but my Explorer handled it OK.

At any rate, in the situation you described, it sounds like the truck and trailer braking were reasonably well synchronized, so you saw no substantial increase in braking effort or distance.

Bill

If you can't afford a new tow vehicle until next year - here are a few ideas so you can get to camp:

Rent a truck.

Borrow a tow vehicle from friends/family/inlaws/outlaws.

Invite someone to go camping that just happens to have a big truck/suv.
Ditto above but they tow TM and drive your sprinter to carry more people.

.

[Wavery]

Originally Posted by Bill

I think you should expect braking to be about the same. Remember that the trailer has its own brakes. In the ideal world, the trailer will stop itself, and do so in the same distance that it takes the truck stop itself - so you would experience no difference at all.

As always, the words "In the ideal world ..." deserve a lot of attention, because we don't drive in the ideal world. In the real world, the tow vehicle and the trailer each do most of their own braking, but you can never adjust things to make the braking effort perfectly equal. If the trailer doesn't brake quite hard enough, the tow vehicle has to take up the slack, and stopping distance becomes a bit longer. But just as important, when the trailer is pushing on the tow vehicle, it has a tendency to push the back of the tow vehicle to the side, which can result in loss of control. The tow vehicle's wheelbase determines its ability to resist this sideways pressure, and short-wheelbase vehicles are a bit scary for that reason.

Of course, if the trailer brakes fail, then you have the worst case. The truck must stop both itself and the trailer, and obviously the stopping distance will be a lot greater. More important, the tow vehicle's brakes have to be adequate to stop both vehicles without overheating and fading out, even if you happen to be on an extended downgrade. This is (or should be) an important consideration in choosing a tow vehicle. And at the same time that the tow vehicle is stopping both itself and trailer, it has to resist the jack-knife tendency of the completely unbraked trailer. This is a big deal! I've experienced partial brake failure on a 10% downgrade with twisty turns. It wasn't fun, but my Explorer handled it OK.

At any rate, in the situation you described, it sounds like the truck and trailer braking were reasonably well synchronized, so you saw no substantial increase in braking effort or distance.

Bill

^^ What Bill Said^^

However, I'm a little confused by this statement:

Originally Posted by Pierak706

Hello,
The Sprinter literally could not make it up the first extended hill we faced (North of Franklin, toward Asheville). It started slowing down severely, and it was clear that it may not make it at all to the top.

Are you saying that you geared all the way down to 1st gear and the TV could not keep up RPM even if it meant driving @ 20MPH (or less) up the hill?

That I have a hard time understanding unless there is something wrong with the TV.

There is nothing wrong with climbing a 10 mile grade @ 20MPH (or less) as long as you aren't experiencing over-heating problems. Find out what the optimum RPM is for your engine's torque curve. If your engine's peak torque is @ 2500RPM (as example), put your transmission in whatever gear you can maintain that RPM at and leave it there to the top of the grade. If you can't maintain 2500 (or whatever that # is), drop it down to the next lower gear and live with it. If you get to low gear, try to back off an extra 500RPM (if you can maintain speed). Remember, the less the RPM, the less the pulling power. If you have a hard time maintianing the optimum RPM for your engine, don't go below that because you will have less available torque to get back up to the optimum RPM. If it will pull OK at 500RPM less (in any gear), all the better.

One of the worst things that you can do to a diesel engine is to "Lug" it. That means to have your foot close to the floor and not be able to achieve optimal torque RPM. It is always better to run any engine a little higher RPM with a little less throttle pressure, in a lower gear than to try to keep it in a higher gear and slow the engine RPM down. If someone thinks that running the engine at a lower RPM while climbing is saving fuel or wear & tear, they are wrong.

10 miles @ 60MPH will take you 6 minutes. 10 miles @ 20MPH will take you 30 minutes. In the total scheme of things.....who cares? If the engine and trans don't over-heat, it may add another hour to a total days driving.....so what?

If you turn off your AC, it will make a big difference in maintaining RPM and lowering heat.

If you are saying that you are having over-heating while climbing (with the AC off), that's a totally different issue. You may either have a mechanical problem or you may be lugging that diesel at too low RPM.

HarveyRV,
What happened is, the Sprinter started slowing down and overheating (air conditioning had been turned off); also when we stopped, there was some smoke coming out of the exaust, not a great deal, but enough to give us pause. The Sprinter usually runs very clean, no smoke whatsoever. Eugene went all the way to the lowest gear. I honestly don't know about the RPM, other than my husband said they 'looked ok'. It looked to us that, had we continued, we would have possibly caused serious damage to the engine.
Your comments about 'lug' are way over my head, they will be passed on to Eugene, who understand this stuff a lot better than me.:-) -but I'm the 'forum nut' in the family, so that's why I'm writing :-[) -
However, you are correct that something is wrong with our Sprinter. Just a few minutes ago we finally got the first feedback from the mechanic. He did indeed detect a definite - but not yet quantified - loss of power. To begin with, the fuel filter appears to be clogged, so he is replacing that (We will be trying to find out WHY the filter is clogged- we have followed all the maintenance schedules and procedures). He thinks that is not enough to explain the problem though, so he will also look at the turbo charger, and a bunch of other stuff (don't have the detail yet).
I have done a lot of research on the Sprinter in the meantime. Unfortunately, the owner manual does not give the GCWR, nor do most of the sites related to the Sprinter. It turns out we own a 2005 (as per title), not a 2004. I kept saying 2004 because that is when we bought it.
Anyway, the only source I found for the GCWR gives a figure of 9500 lb for the 2004, and 13550 for the 2005. This made no sense to me. As far as we could ascertain, there is 0 difference between the 2004 and the 2005 models. I have been trying, without success so far, to find the actual correct figure. 9500 lb would put us on the edge; 13550 would mean that we are well below specs. I have actually sent an email to Freightliner, asking them if they can find that information for us. No answer yet.
Here is what the user manual says about towing weights:
GVWR=8,550 lbs; TWR=500 lbs; GTW=5000lb;GAWR (FA)=3860 lbs;
GAWR(RA)=5360 lbs.
GVW must not exceed GVWR
"When loading a trailer, you should observe that neither the permissible GTW, nor
the GVWR are exceeded...We recommend loading the trailer in such a manner
that it has a tongue wight (TW) between 10% and 15% of the GTW.
The tongue weight at the hitch ball must be added to the GVW to prevent
exceeding your Sprinter tow vehicle rear GAWR...please observe length and
width limitations for the trailer."
Not one word on GCWR. According to the above, we should not have had any problems. We have not actually gone on a scale, but our estimates (erring on the side of over rather than under estimating) are:
Trailer: no more than 3800 lbs
Tongue weight : no more than 450 lbs
TV weight fully loaded : no more than 5600 lbs
As you can see, this would put as at the 9500 lbs limit, but nowhere near the 13550.
Well, stay tuned. I will post what happens after the mechanic is finished. May be a day or two yet. It will be the first time we would be delighted to find out that our vehicle has serious problems...:-[)

[Wavery]

You are certainly within weight limits.

The fuel filter is an unlikely culprit. Turbo is more likely. I hope that you got it to a tech that knows diesel engines.

If you live in a cold climate, your fuel tank may be contaminated with algae. This could be the reason for the clogged filter. This is a common problem with diesel fuel. When you own a diesel in cold climates, it's important to keep your fuel tank as full as possible at all times. Condensation will cause water in the tank and diesel tanks are known for growing algae. The less fuel in the tank, the more water that will build-up from condensation. I have seen diesel tanks so clogged with algae that you could hardly get fuel in them. There are additives available to help with this. There are also additives, that will convert the algae to burnable fuel and clean your tank. You may want to look into that. It is not normally necessary to remove the tank to clean it.

As far as gearing down while climbing a grade is concerned. It's important to get the vehicle into a lower gear in a timely manner. If one finds that the vehicle is struggling in a higher gear, it is better to down-shift sooner than later. The idea is to not allow the engine to drop below it's optimum RPM/torque range. This is especially critical in a diesel engine.

It's a good idea to make a note of the difference in RPM in each gear. In other words, if the RPM drop from 2nd to 3rd is 500RPM, make a note of that. If your maximum torque is at 2500RPM (as example) and you find that you are unable to hold it at that RPM while climbing a grade, it is important to get it into the next lower gear before the RPM drops below 2000.

If your RPM change is 500 from one gear to the next and you allow it to drop too low before down-shifting, you may not have enough torque (power) to maintain RPM at the lower gear either because you will have missed your optimum torque curve. As your RPM decreases so does your available torque/HP.

That is why you have different gears in the first place. If you have a standard transmission, you would never dream of putting the vehicle in top gear at less than 25MPH while climbing a grade because you just wouldn't have enough RPM built up to obtain the HP needed to climb the hill. The same theory applies when down shifting.

Originally Posted by Mr. Adventure

I certainly would have thought your Sprinter would be a good tow vehicle for a TrailManor. The first thing that comes to mind, is that heavy diesel trucks have to work pretty hard to get over the mountain and are hugely underpowered compared to what we're used to on four wheels for towing TM's. It's not that we couldn't get over the mountain in an RV with performance like a heavy truck, it's that we just wouldn't want to.

More to the point, towing isn't a black and white business. There are variables that make things a lot fuzzier than we'd like them to be.

Thanks for sharing your experience!

Huh? I towed a 3326 from TN to FL via I-26 through the mountains west of Asheville using a Ford F350 DRW at 65 mph with the cruise control on. My truck does not get much heavier than they come in that class, why does that make any difference? Towing is about hp and torque, perhaps some underpowered diesel TV's are suspect, but I don't agree with blanket statements that diesels are going to cause towing problems. If you don't choose to own one that is fine, but I can get over whichever mountains I choose with no issues.

To the OP - the fuel filter change may indicate you have biological growth in your fuel tank. Buy some diesel additive designed to kill the "bugs" which will grow in the presence of diesel and any water. They are very common in diesel boats and you can find the additives in marine supply stores if not elsewhere. You also may have a pluggage in your cooling system, and if there is sludge it may be affecting your turbo intercooler (if you have one cooled by the radiator, I did not look up your vehicle to check).

oops - refreshed the page and saw harveyrv's comments about the fuel filter. So I agree...

If the smoke coming out the back of the vehicle was white, that can be coolant leaking into the turbo (once again assuming you have a coolant connection to your turbo, some use oil, my Ford uses both and I just replaced it for $2K!)

Well,
got a little bit more information on our Sprinter. Just as Harveyrv said, it is the Turbo. A valve in it is completely broken, and the Turbo was not working at all. The mechanic has ordered a new valve, which has not come in yet. So, more waiting, but at least we think this may be the last problem, and the Sprinter will be fixed. Not cheap, but much cheaper than buying a new vehicle. Cannot complain too much, we have had the Sprinter for 6 years, and it has not cost us a dime, except for scheduled maintenance. But we'll believe it is OK after we have tested it up the hill!! We are still surprised that the vehicle could have such a severe problem, without any warning from the on-board computer system. We thought that's what the computer system was for. Anyway, I will post again when we have the Sprinter back, and fully tested.