Engine "temperature change" when towing.

Hello All:

Questions:
1) What is normal engine temperature change (rise), while towing?
2) Is changing ?thermostat unit? or removing completely of value in reducing temperature rise while towing?

Following are the facts:

TOW VEHICLE- a Dodge Maxie Van (15 passenger bus), with a 5.9L engine,
TRAILER in TOW -a ?Trail Sport? by R-Vision, less than 4K Lbs empty, and 377 Lbs. on tongue.

While towing IN ?Overdrive? the temperature gauge is at 3/4 of value. Air Conditioner off.
When towing OUT of ? Overdrive?, the temperature settles at 1/2 point. No Air on.
When NOT TOWING, the Temp gauge is at 1/3 position. With or without Air.

Although I have had two Transmission mechanics tell me that this package (engine & Transmission) can pull 4K lbs. in Overdrive with no problems, these facts bother me:
1) The temperature rises twice as much in overdrive?.
2) And I have had to replace ?water pump? twice?.
Details?.? Since never towed before 70k miles, and then only minimally (2K miles),? had to replace water pump at 92K miles. Since that repair, towed another 8k miles, and had to replace water pump again at 119K miles.

Unfortunately (?) very seldom took out of OVERDRIVE for driving or towing.
?
Presently have 127K miles and have completed all scheduled maintenance activities, and recorded meticulously.
Since I still want to get the economy in gas mileage (small) with overdrive AND, the history shows Big stress of Water pump if I continue, is there a solution besides towing OUT OF OVERDRIVE.

Thanking all,

It sounds like your vehicle is telling you that it does not want to tow in OD.  Some vehicles can, some cannot.  If it is marginal in OD it will constantly shift down to 3rd then up again after the grade eases.  That is going to build heat.

Having once had a big passenger van myself (Ford E350 with a 460 V8 sporting a 4bbl) I am prompted ask, what are you hauling in that rolling barn?  Excess load in the truck tend to subtract from what you can haul on the hitch ball.  Even passengers count, the usual nominal allowance used is 150 lbs / passenger. 

Have you had the radiator checked by a good shop?

I carry nothing of weight in trailer.... floors too weak on most....,
Sooo, put most of junk in Van (all but one seat removed) and have a small Generator on tail of Van weighing about 75 Lbs.
Partial list:
Lawn chair, Aluminm ladder, Small Tool Box, large plastic container (3'x3'x2') with power cables, hammers, electric dril, box wrenches and sockets,..... another large plastic container for CD's and electronic do dads.... tarps for shade.... clothes, enough junk for 40 day trip.
? ?
I will be putting Van in DRIVE for all towing.

Thanks again

Hoo boy.  Weigh that rig:  trailer and van  as loaded for travel.  You can do that at a public scale.  You can find such at places like contractors' supply yards or over in an industrial part of town.

The reason?    We talk a lot about tow ratings here, but there is another rating that you need to observe:  Gross Combined Vehicle Weight Rating.    The GCVW is the van wt. + Trailer wt. + payloads in each.    With a big van like yours you can easily blow by the GCVWR with just payload in the van.  In fact, you can blow by the GWR of the van itself.  Read the DOT plate on the drivers door post.

Anyway, no OD seems to be the way to go.

I know on my Dodge V10 the manual specifially states to drop out of OD if climbing hills or there is a lot of headwind or something and the tranny is shifting a lot.  Hope that helps..

Removing the thermostat will destroy the effectiveness of the cooling system and result in boiling.  You can experiment with different temp thermostat.  I have a Dodge 3500 van, and I use a vacuum gauge to warn of impending shift out of OD, take it out of cruise control, and slow down.  Lock out OD on hills (per owners manual).
Art

My owners manual on my Dodge 1500 p/u says to never tow in OD. My TT weighs 6950 lbs and the temp never changes when towing. I follow the manual's advise and never, never tow in OD.

John & Judy

John & Judy.

Any particular reason for that flashing temp gauge/clock in your sig line? It's quite distracting when trying to read your messages. I recently disabled images in sig lines, but you seem to have found a way around it 

I'm sorry, I saw someone else with one and just though it would be ok........i'll remove it right away.
again sorry.

John

Thanks John, that's much better on my eyes!