Community Forums

burfurd · 12-10-2010, 06:32 PM

I am rather new to a diesel pusher and need to ask a possibly dumb question. On driving our coach recently in cool weather (cold actually), I noticed the dash heat was not really doing much good. Is this a common problem with diesel pushers? I know the diesel engines are supposed to run cool and mine does (275 hp. Cummins), but so cool that not very much heat is put out? The temp gauge is not graduated by degrees but it is in the lower quarter of the scale.

Does a diesel engine have a thermostat like a gas engine? If so, what temperature is recommended?

I know I can run one of the furnaces in the coach and that is what I am planning on an upcoming trip south, just wondering.

Thanks....burfurd

Gary RVRoamer · 12-10-2010, 06:39 PM

A diesel engine actually runs rather hot and requires a very large cooling system to keep it cool. But with the engine in the rear, the heated coolant needs to be piped all the way to the front to heat the driving area. And then there is all that glass around you, losing heat rapidly, and an open, unheated area immediately behind the seat. In short, the dash heater is not up to the job in cold weather, so you probably need to run your furnace. Or as an alternative, run the genrator and place an electric heater in the aisle near the front for some extra heat in the living area. I'd probably do that rather than using the furnace, mostly because its easier to get diesel for the generator than propane for the furnace.

Greg Lepage · 12-10-2010, 06:51 PM

Quote:

Originally Posted by burfurd

I am rather new to a diesel pusher and need to ask a possibly dumb question. On driving our coach recently in cool weather (cold actually), I noticed the dash heat was not really doing much good. Is this a common problem with diesel pushers? I know the diesel engines are supposed to run cool and mine does (275 hp. Cummins), but so cool that not very much heat is put out? The temp gauge is not graduated by degrees but it is in the lower quarter of the scale.

Does a diesel engine have a thermostat like a gas engine? If so, what temperature is recommended?

I know I can run one of the furnaces in the coach and that is what I am planning on an upcoming trip south, just wondering.

Thanks....burfurd

Be sure your coolant level is correct. Diesel cooling systems are similar to gas motors and do have thermostats. When the heat on a gas motor blows little or no heat then first thing is to check for a full radiator. If you have a leak you may not know or see it and the first sign may be reduced heater or no heat at all. Check the radiator when it is cool. By the way, your question is not dumb, that is my job to ask those.

dons2346 · 12-10-2010, 07:08 PM

Diesel engines run at the same temps as a gas engine, approx 195. If yours is running cooler, you could have a stuck thermostat. You could also have some coolant shutoff valves somewhere keeping hot coolant from reaching the front of the coach.

By running the engine to cool, you are not getting complete combustion and your mileage will suffer.

burfurd · 12-10-2010, 07:12 PM

Will check the radiator to verify it is full....the overflow tank does have a bit in it. Actually, Gary may have a good point, we could use the ac for a small freezer in the basement as well.

Just have to make sure the electric heater is not in a position to turn over....Guess the wife could keep an eye on it.

Probably will run the rear furnace as it heats the basement (I am told).

Incidentally Gary, am headed for Ocala NF next week. Maybe see you there.

burfurd

Mike Canter · 12-10-2010, 08:08 PM

We have had people on this forum have this problem before. You should find the two heater hoses that go into and come out of the motor. Usually close to the motor or actually where the hoses attach to motor maybe a shutoff valve. There can be just one on one hose or two of them, one on eah hose . Sometimes people shut off these valve so the dash AC runs cooler in the summertime.

MikeandClaudia · 12-10-2010, 08:51 PM

Mike Cantor is right! We have a Dutch Star and there is a 1/2" gate valve high up a little above the frame near the left rear of the MH.

Even with that on, there are enough air leaks in the front that we sometimes need to turn on the furnace periodically.

dynaride99 · 12-10-2010, 09:00 PM

Diesels need to run at the design temp to be efficent and clean burning. Check with engine maker for proper temp. Thermostats are all to often overlooked during maintenance, and should be monitored for good working order. If you are not sure if yours is the right temp range then check it at first chance. Also you may want to install a secondary set of temp and pressure gauges that reads in actual temp and press numbers. Diesel engines run best when loaded and that is when an overheating event can occur. Cheap insurance to monitor your engine. I agree to check for shut off valves in coolant lines and also think about insulation to get the heat to the dash.

burfurd · 12-10-2010, 10:11 PM

Will check the valves and make sure they are open. If still no heat, will have the thermostat replaced.

This gives me a couple of things to check.

burfurd

paz · 12-11-2010, 05:57 AM

Quote:

Originally Posted by burfurd

I am rather new to a diesel pusher and need to ask a possibly dumb question. On driving our coach recently in cool weather (cold actually), I noticed the dash heat was not really doing much good. Is this a common problem with diesel pushers?...

Actually, this is a common problem in almost all motorhomes, gas or diesel. As has been suggested, you may have a valve shut off; but even with the heater operating properly, you're trying to heat a really big volume with a relatively small heater. Not only that, but many motorhomes aren't that well sealed in the cockpit area, so a lot of cold air leaks in, especially when you're moving.

We try not to travel in really cold weather, but if it gets below about 50º outside and there's no sun to help warm things up, we have to run the heater fan on high. We've never run our furnace while moving, but from what I hear, it can be done.

charles tuit · 12-11-2010, 08:24 AM

If all the above suggestions are made and it is still cool in the front, try making and installing a drape behind the driver and passenger seats.

We did this and it makes for a warm compartment in cool weather and a cool compartment in hot weather.

Charlie Tuit
02 Winnebago Journey 148,000 miles
XL-7 toad

Gary RVRoamer · 12-11-2010, 06:56 PM

Quote:

Just have to make sure the electric heater is not in a position to turn over....Guess the wife could keep an eye on it.

Not to worry. Any UL-approved electric heater will have either a tip-over switch that shuts it off if it tips, or will be a ceramic control type that restricts the electric current if it begins to exceed its design heat rating.

In any case, you can get heaters that are low and wide rather than tall and skinny.