Mercedes Sprinter Chassis in Mountains

[Bthomas1956]

I will be interested to know how it goes, the Sprinter has lots of torque so I would imagine you should have no problems, its the torque not the horsepower that get you over hills. I am currently doing a DIY conversion on a 2007 Sprinter 2500 Passenger Van with the 170 wheel base.

Hopelessly lost but making good time
BT

[Fastpaddler1]

I have read hundreds of B class reports on trips and NO BODY YET has admitted that the engine would tend to overheat on long, steep climbs on long hills or in the mountains. My previous V10 would get to near RED and my PW Plateau diesel also. I have asked people and "No" is the response. I even see my new BMW shows increased temp on the oil temp guage(no water temp gauage). The extra engine hard work must cause engine heat buildup despite the thermostat. With the bigger rigs ie the 24 ft and bigger surely this is a factor. Anybody have a comment on that. I am getting my PW serviced shortly and maybe I should do a system flush. I know this is a technical question but it IS relevant to the OP question a while back about buying a Unity(or similar even and how it would manage hilly regions. So please dont dump this comment yet!! Comments about down shifting and so forth are good to and downshifting a new Unity or other rig on hilly climbs makes sense.

[Mike]

Originally Posted by Fastpaddler1

I have read hundreds of B class reports on trips and NO BODY YET has admitted that the engine would tend to overheat on long, steep climbs on long hills or in the mountains. My previous V10 would get to near RED and my PW Plateau diesel also. I have asked people and "No" is the response. I even see my new BMW shows increased temp on the oil temp guage(no water temp gauage). The extra engine hard work must cause engine heat buildup despite the thermostat. With the bigger rigs ie the 24 ft and bigger surely this is a factor. Anybody have a comment on that. I am getting my PW serviced shortly and maybe I should do a system flush. I know this is a technical question but it IS relevant to the OP question a while back about buying a Unity(or similar even and how it would manage hilly regions. So please dont dump this comment yet!! Comments about down shifting and so forth are good to and downshifting a new Unity or other rig on hilly climbs makes sense.

FWIW, my engine temperature always rises when I climb hills, especially in the western mountains in warm weather/climates. I have a 5.7L V8 Chevy engine pulling over 4 tons of van, and it runs warmer when placed under extended periods of stress, as in higher continuous RPMs, under increased load. All engines do.

[booster]

Originally Posted by Mike

FWIW, my engine temperature always rises when I climb hills, especially in the western mountains in warm weather/climates. I have a 5.7L V8 Chevy engine pulling over 4 tons of van, and it runs warmer when placed under extended periods of stress, as in higher continuous RPMs, under increased load. All engines do.

Perhaps Marco will be able to jump in and let us know how his Chevy diesel does temperature wise, on long hills. I don't recall if he ever has talked about that. Most of the diesels we hear about are Sprinters, so we really don't know if all diesels do better than the gassers for heating up, or not. Usually, the gassers have higher horsepower, so they can probably climb faster, which also generates waste heat faster, so that could also contribute. I am sure running them up the hill a bit slower, or down a gear from max they could pull, would also help them run cooler.

[Mike]

Actually, as I've said before, if I get stuck behind a slow moving truck or other, on an uphill grade, and can't do the NASCAR pop out and pass thing because I'm too slow at that point to do it safely, I have seen the temp gauge climb even faster, because I can't get enough air through the rad at low speeds to offset the increased engine load. I should probably add your rad fan mod to help keep the cooler air flowing through the grill. That was a nice one.
OK, so how do we get Marco to get out there and test it? A little trip through the Appalachian mountains would probably do the trick?

[Fastpaddler1]

Thanks. I think we can conclude that it is natural to have some heating up of the engine on long uphill climbs. I will get the coolant changed and check all the hoses and serpentine belt etc and head East--as I usually go South to my favourite USA hangouts!

[Mike]

I should also add I switched from Dexcool to the "green stuff" a few years ago, after doing the intake manifold gasket fix after we spotted an external coolant leak. We were lucky and caught it in time (actually, the copilot spotted it ) before any coolant got into the places it shouldn't be. I haven't noticed any difference in the rate of coolant temperature increase on long climbs in warmer ambient temperatures. It may recover slightly faster, but I have only empirical data to support that, just a feeling that we cool down faster on the downhills or flats, since changing coolant types.
Maybe diesels just run hotter by design, and their temp gauges don't move much when they are under stress.

[booster]

Dexcool and the green stuff are both ethylene glycol based, so I would expect them to cool very similarly. The additive differences are mostly in how they attempt to prevent corrosion, particularly of the aluminum parts. It is mostly the concentration of antifreeze to water that will make the biggest difference, with more water better. I have read more on antifreezes than any sane person would have and still don't know what the right answer is. Dexcool has a horrible reputation, but many folks have had no trouble with it. Most who switch to the green stuff have no trouble, but you need to change it every two years. We decided to go with GO5 rated in our GM stuff, which is long life like Dexcool, but not as aggressive on things like gaskets. I have no idea if it is the right choice.

Many folks in the hotrod community swear by a product called "water wetter" which allegedly changes the surface tension of water, improving the heat transfer rate. I have tried it in the past in our old Challenger and got no benefit. It may have to do with if you are short of radiator area or airflow in your particular application. We were short of airflow, so it didn't help.

[Mike]

The answer is probably that there is no answer. I just try to keep up with the p.m., stay alert to potential problems, and try to drive our van "easy" uphill. Get a run at it if possible, try not to get trapped behind slow moving truck traffic, and ease back on the gas/gears if necessary. I probably baby it too much at times, but that's what we do. If we decide that the Roadtrek is going to be the last RV, after all, I may consider getting that engine work done that I was considering a while back. A little more HP and torque can't hurt.

[Fastpaddler1]

I will get the Sprinter t/d PW flushed and refilled shortly and will ask MB what they recommend for an all season coolant, especially for hotter weather which is when we are on the road the most.
Thanks for all the info re your specific rigs.
AL

[accrete]

Greetings, I saw mention of "gassers" related to hill climbing and thought i'd share my experience with our 2010 Chevy 1500 AWD van conversion. My comment is made in reference to this post:

Originally Posted by booster

...Perhaps Marco will be able to jump in and let us know how his Chevy diesel does temperature wise, on long hills...Most of the diesels we hear about are Sprinters, so we really don't know if all diesels do better than the gassers for heating up, or not. Usually, the gassers have higher horsepower, so they can probably climb faster, which also generates waste heat faster, so that could also contribute. I am sure running them up the hill a bit slower, or down a gear from max they could pull, would also help them run cooler.

I just double checked with my wife who does most of the driving and verified the temp guage remains fairly steady at 210 no matter what we are asking the van to do. I've driven a few mountain passes also. In particular i recall driving over the coast range and doing the NASCAR pass around a class A struggling at ~50mph. We were towing our 15 ft travel trailer and i was easily able to accelerate to 65+ while passing uphill.

Here were the stats for that trip:
Van (weight at scales ~6900lbs of available 7000 GVWR)
Trailer (weight at scales ~2300lbs of available 5000 to GCVWR)
Specs off the chevy website for our rig:
5.3L v8 flex fuel/gas
Horsepower @ RPM 310 @ 5200
Torque @ RPM 334 @ 4500

Average mpg for that trip of ~600 miles was 16mpg in our two room 34ft articulated motorhome

Thom

[obgraham]

In the world of big diesels, like Pusher Class A's, it's a matter of power (torque) and speed. Most of them have a torque curve which shows maximum torque at a certain RPM, say 1650 for my Caterpillar C-7. So if I find a gear to run in which will allow me to ascend running at 1650, I'll generate maximum power on the climb, and then accept whatever speed that results in. A giant 500hp will go up the same hill faster than mine (I should hope!).

So why should these smaller engines be any different? Isn't the principle of the diesel engine the same?

I would expect to be able to climb most any hill. The only thing up for discussion is how fast.

[booster]

Originally Posted by obgraham

In the world of big diesels, like Pusher Class A's, it's a matter of power (torque) and speed. Most of them have a torque curve which shows maximum torque at a certain RPM, say 1650 for my Caterpillar C-7. So if I find a gear to run in which will allow me to ascend running at 1650, I'll generate maximum power on the climb, and then accept whatever speed that results in. A giant 500hp will go up the same hill faster than mine (I should hope!).

So why should these smaller engines be any different? Isn't the principle of the diesel engine the same?

I would expect to be able to climb most any hill. The only thing up for discussion is how fast.

Very will stated, although I think it will actually climb faster if you set it at the hp peak instead of the torque as climbing is using work, not force. Like you said, if you can always get up the hill, but the power ratings determine how fast, and it doesn't matter if it is gas or diesel.