I had only partially tested the replacement 199 degree hydraulic fan speed controller up to now. Not full desert summer weather and grades.
Fixed that testing gap today. Went up Baker grade on I15 at 2pm and the worlds largest thermometer said 113 F.
Engine hit 215 in high gear at low rpm. 65? Mode on.
Mode off. Downshifted to 4th at 1800 rpm and the temp stabilized at 213. 58? Mph.
On level ground engine went back to 189. 109 outside.
Arizona and Utah have 75 and 80mph limits.
I was towing at 70 to 72 up and sometimes higher down hill.
Coach engine is at 8mpg.
Engine maintained small to medium temp rises on grades at those temps.
Very pleased as I have driven a lot of coaches in similar conditions. The m11 and the 199 controller did really well.
I could have motored up the grade much faster and ran the temp up more easily. But why stress things. Not late.
36,000 pounds combined.
I thought I could feel the difference in engines pulling power under loads with the fan on high at high rpms manually downshifting the trans versus similar grades at the same rpm but with the engine at 185 range.
Same pulling differences at low rpm with mode on and hot motor versus normal temps.
Subtle but noticeable if you are tuned into the test.
Thank you for that post.
If my M11 gets over 190 in the mountains I'm a nervous wreck keeping my eye on the Silverleaf hoping all is well. It's mostly flat land and rolling hills where we live and the coolant temp stays right around the 180-185 mark, even on 110 degree days. (I guess I drove too many old Chevrolets and Oldsmobiles in the old days when overheating was the biggest cause of failure on the highway.)
Someone put my mind at ease about what is normal for these coaches when climbing. It seems to me the shut down bell dings at 220 or something like that. It happened once when our fan controller failed on our previous coach.
Once again, I'm grateful for all the wisdom on this forum.
I owned to GM 6.5 diesel pickups. Burned one down and struggled with the other, so I as well watch the temp gauge probably way to much! I would think that 215 is maximum we want to see on these rigs. I know most trannys say 235-240 is death heat
My ISC runs down the rolling hills roads from 180 to 185 or so, it will see 205 on some long pulled if I let it. I try to keep things below 200. I well know they will stand much higher engine temps, but one must consider these things are not new. All those o-rings and gaskets are getting old.
Yes on both counts. 235°-240° over a period of time is death heat. Here is a chart with mileage. That's why I back up our driveway. Lots of slippage in first and in 300 feet, the tranny hits 300°. Easy climb in reverse.
Unless you have some CATs or 5.9 Cummins, you have wet sleeve engines. They won't stand as much heat as the parent bore or dry sleeve engines. Overheating has a cumulative effect.
Pierce
There should be an equivalent chart for decreasing life of trans fluid with temp. Transynd should be less sensitive.
The chart is for tranny fluid. I should have put a larger label on it.
My second paragraph addresses Dan's post about 215° being the maximum temperature. There have long been those who charge up grades in summer and talk about 230 degrees, etc, etc. I lost a belt and had the DDEC ECU go into shutdown mode but I was not sure about the exact temperature. So I went to the Detroit Diesel manual and looked it up and posted it below. As Bruce posted, our O rings, etc are getting older and even though we may treat our coaches well, the PO may have not so it pays to drive on the conservative side.
The 6V-92TA as found in U300 has a 210° maximum temperature with the alarm sounding and the half power shut down starting at 215°. The partial power shut down lasts for 30 seconds, long enough to get to the side of the road and then the DDEC shuts the engine off. There is an override switch but the abuse of the override may damage the block to the point that it may not be repaired.
Pierce
Delivered and drove a lot of 6v92's and had the 93's at 230+ without by bells. I should state now that I might not do that now with the info available and the post here about the effects being cumulative.
First time I did this was on a test run on a early unihome reset from 277/840 to 300/820 with 2 Detroit engineering techs in the coach with me. Same baker grade. 110 outside.
Foretravel set there own engine parameters in-house. Did not have to go through Detroit's mainframe back then.
My earlier coach memory was 235 for alarm and 250 shut off but hey it's been 32 years and even though I mentioned this hundreds of times maybe I remember incorrectly.
JamesT would know for sure.
Separate issue from our summer drive yesterday. Pulled into Walmart at 6pm. Toasty warm at 97 degrees.
You experienced guys probably know what's next. Yup at 11pm I shut off the gen as the ambient temp outside was high 70's
Bedroom got very warm. 2 tons of engine, trans and radiators had not cooled off that much. Should have left the gen on.
Coach is not in the condition to use this way. Grille area is small. Needs fans. .better insulation. Stop earlier. Keep out of 100 degree weather. All of the above?
Gen is marvelous. Giant watch running. Down a 100 amp hours overnight. 84% left. 12.65 volts. Batteries appear good.
Interesting observation. I left the refer on by accident with the doors wide open for a few days on propane while at home.
70's outside. Coach level. Shades closed.
Slight ice in freezer section. Metal in refer cool but no ice.
Refer gets noticeably colder now. I guess it needed to be fully on for a few days never going off to renew itself.
solar recharged any battery use.
Rm 7832. Dometic. 32" width.
Icemaker compressor makes a noise if turned on. I read a post about lubing the compressor motors fan somewhere?
Something about using a bent metal rod to convey oil to the bearing and successfully fix the noise.
Anyone remember that or do this themselves?
Refer works really well now. Hate to scrap it quite yet.
If you unit(refer) no longer works as well the open door and on may help it. It sure helped mine.