RPMs on 2000 D

[Colesmeister]

We have a 2000 Discovery, 275 hp. I was wondering what is acceptable for RPMs when pulling a hill. On the flat, I'm normally running 1700 to 1800 RPM. On steeper hills, what should I hold the RPMs at?

The reason I ask is because after a trip to Montana from Washington state, on one hill, the temp got higher than it ever has. I think I was blowing black smoke out the pipe because of the dirty condition of the toad when we got to our destination, although I didn't notice any smoke while we were travelling.

Any advice greatly appreciated.

Greg

[Colesmeister]

We have a 2000 Discovery, 275 hp. I was wondering what is acceptable for RPMs when pulling a hill. On the flat, I'm normally running 1700 to 1800 RPM. On steeper hills, what should I hold the RPMs at?

The reason I ask is because after a trip to Montana from Washington state, on one hill, the temp got higher than it ever has. I think I was blowing black smoke out the pipe because of the dirty condition of the toad when we got to our destination, although I didn't notice any smoke while we were travelling.

Any advice greatly appreciated.

Greg

[Gary RVRoamer]

If you had black soot on the toad, I would guess that you have either unburned fuel going out the exhaust (injector or valve problem?) or oil venting from the engine. Either indicates a problem and maybe why you had to pull more RPMs than usual to climb a hill.

Does your dashboard have a tach with a visible red line? It is acceptable to run up to the redline but desirable to stay below that as much as possible.

[Don (W5IT)]

Greg I had a 2000 Discovery with the Cummins 275. The Allison transmission will shift up and down as needed. SO I would not worry as much about the RPMS. Between the computer on the tranny and the engine they will keep the engine and tranny protected.

The temperature rise could be from a dirty radiator. Your rig has the rear mounted radiator. So all kinds of stuff collects there that restricts air flow.

I would suggest (If you have not already done so) opening up the engine access from the inside of the coach and cleaning the radiator. I use a couple gallons of "Simple Green" in a garden sprayer.

Spray the engine side of the radiator giving it a GOOD soaking. (Enough so you can see it running thru to the other side if possible) Then after it soaks for a while, use your trusty garden hose with a stream spray nozzle from the other side (Rear of the rig) of the radiator. Make sure you take your time so there is a lot of flow thru the radiator until you have rinsed all the radiator fins throughly.

That usually gets the air side real well. The water or coolant side is a LOT more involved.

I used to change the air filter every year also. But that will not affect the temperature. But can cause additional soot to be sent out the exhaust pipe.

I may have posted stuff you already know or have done, but just things I have done to solve a similar problem.

[Trehcub]

When you are pulling a hill you will need to down shift and keep the engine RPM around 2000 or so. The reason for this is that the radiator fan turn faster at the Higher RPM even if it is side mounted due to the pump being driven faster. Allows for better cooling.

If you have your foot feed all the way to the floor, all you are doing is adding extra fuel that is not being used and adding heat to the engine. The Engine and trans computer do work together and will keep you from shifting to a gear that would hurt the engine or trans, but it will not keep your engine from overheating or being worked to hard due to a hill climb.

Just watch your RPM's and Temp and try to keep the RPM's high enough to keep the engine cool and the foot feed not pressed to the floor.