Engine and trans temp

[Glenn Scherrer]

I have a 1998 patriot  with the 3126 cat rear radiator it runs hot on any grade 4 deg. Or better     I have changed the trans fluid to the transynd  Cleaned the radiator both inside and out added eletric cooling fans to the out side of the radiator still runs hot 220 before I pull over   on flat ground even towing it runs 188  looking for ideals  like adding a transmission cooler separate from the radiator  like a engine oil cooler  like ducking fresh air from the side of the coach to the radiator  coach has 60k miles and runs great  

[Larry Fritz]

Glenn, I have a ton of info on this same coach and your issue. I sent you a e-mail with my phone number if you want to call me to discuss. Far too much info to put into this forum.

Larry Fritz

[Steve Huber]

Glenn,
I had a 01 Contessa with the 3126B / rear radiator. It would run at 194 when flat towing. In hot weather if I was fighting a head-wind it would try to run at close to 200. Hill climbing could drive it to 220+ until I started doing the following: The temp rise is due to the design; all air to the radiator is coming from underneath the  coach and efficiency is poor. The remedy for this is RPM. One needs to keep the fan and water pump turning as fast as possible. I never used the economy mode as it tended to lug the engine by delaying shift points and allowing the RPM to drop too much. When approaching a hill take it out of cruise control, depress the accelerator to its max and downshift as soon as the tranny indicates a shift was needed. Lock the tranny in that gear and keep the accelerator down all the way. Downshift again if the tranny indicates it's needed and again lock it in that gear. Often times I'd be in 3rd by the time I got to the top of the hill. Goal is to keep RPMs between 1800 and 2000. If RPMs dropped below 1800, I would again downshift. Using 5th instead of 6th gear on the flats on a hot windy day also may be needed if temps rise. One  summer I drove across OK in 5th to keep the temp down. The faster you can keep the fan and water pump turning the better. This procedure  worked well for me. One other helpful aid was to set my GPS to read altitude. Then I could verify that if the engine temp was starting to rise, I was on a slight incline.
To summarize the approach that worked for me over 85K miles:
- Don't use Economy mode
- Don't use CC in the hills
-Downshift as needed to keep RPMs >1800 RPM
-Use GPS if possible to monitor altitude.

Couple of other considerations; clean your radiator after each long trip and be sure the crankcase breather drain is routed to a point behind the fan.

Hope this helps; Steve

[LarryNCarolynShirk]

Glenn,

Two other modifications Beaver made to my 1998 Patriot in an attempt to increase cooling:

Installed a smaller fan pulley to turn it faster.
Install a 9 blade fan.

Changing to Transynd in the transmission was the most help, about 15 degrees cooler.  But Steve is correct.  Keep the RPM over 1800.

Larry

[Glenn Scherrer]

How much did the 9 blade and smaller pulley help?

[Marty and Suzie Schenck]

When we bought our 98 Monterey with the 3126 engine it included a bulletin from Cat. It stated: the Allison transmission computer does not communicate with the Cat engine computer. Therefore the transmission doesn't know when the engine is getting hot and to downshift to keep RPM's up. The owner must manually downshift the transmission to keep RPM at or near 2300 to help keep temperatures down when climbing hills or mountain driving.
Marty

[David T. Richelderfer]

My Marquis has an additional radiator for the transmission for extreme temperatures.  Beaver owners I have chatted with at rallies tell me they knew the prior owner and the prior owner complained of high temperatures so he had the additional radiator installed.  I have had the Marquis for just over two years now, and have never seen the transmission temperature north of 140.  And that was only on hot days going up hill.  It usually runs at about 20 to 30 degrees over the outside temperature.

Does your coach, or Beaver coaches in general, have room for additional radiators for either engine cooling, transmission cooling, or both?  Just a thought...

[LarryNCarolynShirk]

Glenn,

I do not recall to what degree the fan and pulley change altered the temperature.  Be sure the engine breather tube is extended behind the radiator and has no dips in it to collect oil.  Any hose of appropriate size will do.  Without this extension, the oil fumes from the engine are swept into the radiator.  The oil collects any dirt swept under the coach and pulled through the radiator.  This collected dirt restricts air flow.  That explains the need to keep all surfaces clean on an ongoing basis.  There is a space between the radiator and the air cooler you can not easily reach.  That space can accumulate debris.  If all else fails, you may want to drop the radiator to clean the space between the two units.
As I recall, the transmission cooler is incorporated in the bottom section of the radiator.  That close proximity would tend to keep the engine and transmission temperatures similar.  Because the Transynd reduces the transmission temperature, the engine temperature was reduced also.  Of all the modifications attempted, that change to Transynd had the largest effect on reducing operating temperatures.

I wish you success in your endeavor to keep cool.

Larry