Is 205 degrees Farenheit a satisfactory operating temperature? I am towing a Chevy pickup, weight 5300 lb. The weather conditions were 93 degrees at 3 pm on a hilly area east of Amarilla, Tx., on hwy 287 at 63 miles per hour. I know the manual states that the operating range is 180 to 212, but, I was wondering if the 205 degrees reading was excessive for the conditions?
do NOT trust dash gauges
We have driven our 1997 U295 (~28,100#) with Cummins C8.3-325 about 15,000 miles pulling a 4,180# Jeep. We normally drive at 65 mph when conditions are good. I don't recall ever seeing the coolant temperature rise above 190F according to the gauge on the dash. The temperature normally registers just below 180F.
My '99 U320/ Cummins M11 450 dash gauge frequently shows 190 to200 degrees or more when VMSpc shows a steady 176 degrees for coolant temperature. I don't know if some of that can be attributed to differing sensor locations.
I tow my 07 Tahoe - likely 500 lbs higher and never break 200F. My M11 is only 400 hp, but I'm 40 foot, too.
Recommend the VMSpc. it uses the same sensors, but reads much more correctly, Maybe at 63 mph that is about 1375-1400 rpm, I would either pickup the speed or shift to 5th, 62 is about where it shifts into 6th, so that is a very low rpm. get the engine rpm up a bit. That may be a hold over from the Detroit days.
Don and Donna,
Here's a thread from earlier this summer on just that same subject (and same route in fact)
Hot Temps And My Worry Gene (http://www.foreforums.com/index.php?topic=13322.0)
Ambient temperatures were much higher and the gauge temperature a tad lower, but still in the range. as folks have said, better to have the VMSpc numbers if you can.
Backing down to force the tranny one gear lower and thus engine rpm higher can help.
Michelle
Dave, Are you sure the engine ECM uses the same sensors as the dash gauges? That's not the case with my DD S60. Typically the ECM sensors are on the CANbus whereas the dash sensors are not. VMSpc sniffs the CANbus.
Don,
I would say 205 is a bit high for your conditions as I just returned from dropping off my coach at FOT and it was showing 183 degrees (per VMSpc) instead of its normal 180. Temperature outside was 104 when I arrived. I cannot tell on my 2000 exactly what the temp is running on the dash gauges at all and like other members love the VMSpc. I would consider buying the VMSpc, as I do not trust the dash gauges at all on my coach. They will show a trend, but may be 10 to 15 degrees off from the VMSpc. Maybe the newer coaches have better gauges than my 2000 FWIW.
287 Westbound East of Amarillo is a steady climb. Doesn't look like it is. You are towing a lot of weight. Rule of thumb. When temperature reaches 200 degrees, slow down a bit to decrease drag. Shift to a lower gear. Keep the rpm a minimum of 2000. 2200 won't hurt the engine. Analog gauges can be off a few degrees. Remember what is a normal reading for your coach. And adjust speed and rpm if it goes much over that. Out West on 6-7% long grades it becomes essential.
Thanks to all for the input. I will put it all to use.
Don and Donna
I went through that area when the outside temp was even higher this summer. I can only rely on the dash gages as I have the mechanical engine, but engine temp was between 180 and 190. Check that the radiator and CAC are clean and free of leaves and grass. Even if no leaves both could have a coating of baked on dirt. Many owners have found this to be the case.
Not sure about your coach model, but on ours (99 U270, ISC 350), the dash temp sensor is totally separate from the ECU sensor that the VMSpc reports on. The dash sensor is on the output of the heater loop that supplies engine coolant to the heater box in the front of the rig, and is easily confused by radiant heat from the turbo and coolant flow (or not) to the heater box. Lots of times the only way I can get the dash temp gauge to be close to the VMSpc reading is to turn the front heat on full to get fresh coolant flowing past the sensor, and wait for a couple of minutes. I only trust the VMSpc reading.
ISL 400 hp Cummins on 30,270 lb U270 36ft FT plus towing 2 door jeep wrangler (this FT rated to tow 18,000 lb). Same highway, Amarillo, and 105 degree afternoon in July. Dash temp gauge showed 200 degrees at 62- 63 and engine rpm 1550-1600. Hope that helps. Mike
High altitude makes me run a bit hotter but most of the time my coach is at 180 by silverleaf and e dash is pretty close too. My 2000 was the same. You are a bit too hot I think.