Weird heat issue

[Geom]

Tom, thanks file the info on your situation. So that makes me feel quite a bit better. It had actually been running ok and manageable until that time it decided to just keep heating up.
We too have misters installed. They're currently InOp because of an earlier water tank snafu and replacement. I haven't replumbed them back yet, because we haven't really needed them... until now. But I had always intended on getting them functional "just in case", and I guess that case is now

When folks refer to the "air cleaner" is that the intake air filter/canister? If so, we replaced that at our last maintenance visit with a new one. So it should be ok, assuming no other unusual failure event. And it runs great otherwise so I doubt the filter medium/etc failed or collapsed or similar. But I suppose I can pull the intake on the turbo and take a quick peek.

I had been wanting to get an IR snapshot of the engine while running and post-shutdown for a while now. So I suppose now is as good a time as any. I'm assuming the best place to get an idea of temps is to shoot the return (top) water pipe going back to the radiator??

Don/Cary, thanks for the info on the tranny rad and the fluid flow. I had it backwards in my head. So if fluid is flowing out of the bell housing, into that line running to the rad (past the sender), then back around to the heat-exchanger in the bay; then in theory that should be the hottest point for that fluid (if not directly in the bell housing). Sometimes it... hops and reports a temp, fairly steadily (only when working hard), then quickly goes back down below guage scale range. So it's probably just a bad sender. I'll elevate the priority on swapping that out.
Thanks for the guidance on not moving the fan. I guess my thought there was to push more fresh air to the portion of the engine rad that doesn't have the tranny cooler in front of it, to better aid that section cool more. But that sounds like it might be a bad idea?
I plan on getting the misters working again. I'm going to replumb the way they were sourcing off of the fresh tank. We've since replaced the fresh tank, and I (intentionally) didn't hook that back in for a few reasons. But I did/do want the mister working, so my thought was to plumb in a one gallon water reservoir for the pump to draw from, instead of from the fresh tank as it used to before. That's on the agenda this week.

I've also been tossing around the idea of building some louvers, that I can position over the side cover of the radiator area, and angle them into the wind to draw more air and force it toward the rad. I'm thinking of maybe 2 or 3 angled pieces of plastic, or wood, or aluminum about 2 inches wide by 36 inches long, angled sticking about 1-2 inches up.
Thoughts on that?

We plan on making our way toward Colorado Springs next week and I'll for sure complete the mister project by then.
The louvers might take longer. I don't want them looking cheesy, so I'll undoubtably spend countless hours in analysis paralysis on it

Also, the InOp temp guage in the bay is simply a directly attached mechanical gauge. It has no linkage to the over-heat system, which appears to be intact and working to me.
I have a replacement on order, but won't be at a place where I can work on potential-coolant-leaking-out projects for a while.
I'm assuming that the overheat system has a different trigger in the engine (according to the manual it's a dedicated sensor/switch).

Thanks again all,
George

[Cary and Don]

Don't waste your time with the louvers. It had a set when we got it and they didn't make a bit of difference. And they were UGLY.

We plumbed the misters to the tank because we had a five gallon tank mounted down by the water pump for the misters. It went dry too fast. One gallon isn't going to get you very far. The mister heads didn't put out enough volume to work. We put those two little sprinkler heads on because it would drop the temp fast. The mister type heads we tried first tended to be so fine that the water didn't get to the radiator. It just blew away.

Better to have too much water on a hot day than not enough. Don't want to get stuck going down the road with the temp over 200 and no where to stop.

It does sound like the temp sender might be bad. The transmission should be about 10 degrees higher than the motor. If it's jumping, that sounds more like a wire. Those don't cost that much, just take it to a heavy  duty parts store.

Don and Cary

[Seangie]

I think you got plenty of info here.  If you are not breaking 200 you are not running over temp.  Especially at altitude...  over 5000 feet.

We are currently on the other side of the rockies (Durango) and when I get in the mountains I always have a hard time.  Usually because I cant always tell how steep the climb is.  Sometimes it will seem like Im on a flat yet Im losing speed and temps are rising.  I just had a heck of a time going through Santa Fe at 85 degrees in direct sun trying to keep my bus from hitting 205.

What Ive learned to do is to stop trying to figure it out and let the bus drive itself.  The most important thing is the higher the RPM the cooler the engine. 

Ive got a 6v92 turbo with a 740 auto.  If Im running at 55mph the 740 will naturally have me in 4th gear but my rpms will be low, like 1800 (Im guessing here as I dont have a working tach, just good ears).  If I have the slightest bit of incline, in 4th gear at that rpm itll start adding heat.  Not always alot (depends on the incline) but it will run warmer if I cant get those rpms up.  If I drop it into 3rd there at 55 Ill be at the very top of 3rd (22 -2400 rpm?) 

Now I can do 55 all day without adding heat until I start to lose speed... I dont force it.  Ill back off the pedal until I get to the point where it just barely starts to slow down and hold it there and let it decelerate naturally.  Someone told me to drive it like theres a raw egg under the pedal.  That helped me to understand it better. 

When it slows down to 37 - 36 mph, Ill kick it into 2nd and again the rpms are up keeping it cool.  If its a hot day you just let off the accelerator and let it drop to the next downshift.  No sense trying to push more heat out of the engjne.  Usually if I lose speed through second down past 27mph Ill just let it coast down to 19mph and kick it jnto first and troll up the hill at 19-20 mph with the engine running against the governor till I get to the top.

1. Get a gun.  Itll tell you all the secrets of your bus, hub temps, brakes, tranny, tstats.  It doesnt lie.

2. Run your bus without adding oil until you get to the low mark.  I used to overfill mine not realizing it.  Once I stopped adding oil it stopped burning oil and now I dont add any but maybe a quart once every 1000 miles.

3. Breaking the ice - Ive learned that there is a magical temp your bus will run fine at (like 190) and once you break that temp you just have a heck of a time losing the heat.  Sometimes its better to just pull off and run the high idle, reset so to speak, let it cool down and then head out again.  Its weird.  Mine will run fine up to 195 but once I break that I just cant get it back down until Im headed downhill again so I try to keep the rpms up once I approach that 195 mark.

4. Hills will play tricks on you.  I remeber heading south out of Denver last year and I was in 4th gear pulling 58-60 mph and rpms were right where they should be and it kept getting hot.  Couldnt figure it out.  It seemed like we were on the flats but it was a slight incline over 15-20 miles and the heat just caught up to us.

5.  Altitude, like the guys said earlier... when you start getting up to 5000-6000 feet your bus is gonna do weird things like smoke and run hot.  Lack of air will do that.  Those are issues I have...  not enough air intake.

Have a good trip.

-Sean

[Lin]

As mentioned, make sure your gauge is accurate.  Both the sensor and gauge itself could have problems.  Also make sure the gauge is well grounded. 

[DMoedave]

I have a small level next to the driver window to help me with the inclines. sometimes you think your going level but your not!! it helps me.

[Cary and Don]

On the determining the grade. Going into Las Vegas didn't look all that steep. But the Eagle got slower and slower. That was a very long grade and it caught up with us pretty fast and it goes on for miles. It also started at some altitude.

We use the GPS to keep track of climbs and speed. The GPS really tells us how fast we were climbing. We watch the GPS for altitude. Usually you start a climb before you realize it. Then you are playing catch up. We use the misters on and off over most of it if the temps start to rise. It's just easier on the engine.

We did Hwy50 through Nevada to Utah. Those climbs didn't look like that much, like from 5000 feet to 6000. But starting out that high made the climb a lot harder. That 1000 feet of climb at sea level is nothing for the Eagle. The ones starting at 6000 feet and going to 7500 feet were even slower.

Welcome to the West. LOL

[luvrbus]

One great thing about owning a Eagle the radiators are so easy to upgrade where they can handle the heat then you don't need the misters

[chessie4905]

#1. Buy a surplus altimeter or set your GPS in the corner setting to altitude if it is available on yours.
#2  INSTALL MISTERS!!!!! Sure, a good cooling system doesn't need them, etc,etc....but they are easily installed and are inexpensive and can save an engine or cracked heads in those occasional times like you are experiencing, which is common with two cycle owners, especially in GMC's, most of which have been upgraded for more power. Diesels, especially two cycle Detroit's are NOT tolerant of overheating. Many times the damage doesn't show up till a couple hundred miles later, depending on how severe.

[eagle19952]

still ignoring the shutdown system ?

cheap way to save $30,000.00.

[edvanland]

I am having the same problem on my MCI 7 and I have done way more than you to try to keep it cool. By the way my misters are made using drip irrigation 1/2" tubing with 180 degree nozzles it works really well. I am going to check on a turbo muffler for mine as suggested, see if that helps. Good luck I live in central AZ and any time I leave home I have form a 7 mile 6 percent grade to a 17 mile, if I am really daring and going east I have about a 40mile one, I don't go that way. Good luck and welcome to the high county and over 100 degree heat on a cool day.