Author Topic: Running at higher elevations.  (Read 5943 times)

Jeremy Parrett

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Running at higher elevations.
« on: September 27, 2015, 04:23:29 PM »
Climbing past Denver.CO to Colorado Springs the transmission temp rose from 175F to 190F and the engine coolant temp rose from 185F to 200F or higher sometimes. Running the C12 at 2000 rpm or close to it to keep the radiator fan at its full potential.
  We are headed through the Vail Pass etc to Moab next week.
 I am using a 7 lbs cap on the header tank.  I am going to replace it with the standard 18 lb cap.
 Is there anything else I can do to lower or better manage these  temperatures ??
« Last Edit: September 27, 2015, 04:33:38 PM by Jeremy Parrett »

Steve Huber Co-Admin

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Re: Running at higher elevations.
« Reply #1 on: September 27, 2015, 10:50:26 PM »
Jeremy,
The  temps you noted don't seem out of line for a C12 when climbing. It will reach those values on a steep or long shallow climb. Check engine is triggered around 215. That said, there is only a 755 ft elevation  difference between Denver (5280') and the Springs (6035'). I don't recollect any significant grades on that stretch of I25, but it's been a few years since I've driven it. Was the outside ambient fairly hot? That can drive temps up also. If your reported temps occurred when running flat in the 2000 RPM range, you may have a problem with the fan speed, thermostat, etc. Not sure I'd switch to the higher pressure cap. Splitting the surge tank can be ugly. Also, be sure to check your coolant level. I had a similar problem with my Marquis and found that the heater core had developed a leak that slowly depleted the amount of coolant. The engine will run at close to  normal temps until you put a load on it.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Dave Atherton

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Re: Running at higher elevations.
« Reply #2 on: September 28, 2015, 12:16:26 AM »
Jeremy, vail pass is 10,500 ft. Myself I would not go with the higher radiator cap As Steve is correct.
Your engine peak torque is at 1200 rpm is 1550 lb/ft,  Boost Pressure 23.5 psi,  Low Oil Pressure 14.6 psi,
Temp at water pump inlet 198 DEG F,  Max Altitude 1007 ft., Inlet Air Temp 122 DEG F. It would be
My suggestion to drop the engine down in rpm's and let the Max engine work. This will give you some Idea what engine is doing. What you posted you are ok the way your engine is running.
The ceiling altitude above your engine spec. will not hurt your engine. One thing about your engine
Your max HP. Is on the reverse side of engine power curve. Your engine is equiped with all the safety
derate and shut down without damage to your engine. You are not losing coolant.
Dave Atherton Retired Cat Mechanic

Dave Atherton

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Re: Running at higher elevations.
« Reply #3 on: September 28, 2015, 12:20:10 AM »
Jeremy, correction on Max Altitude for C-12, 10,007 ft not 1007 ft. Dave

Jeremy Parrett

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Re: Running at higher elevations.
« Reply #4 on: September 28, 2015, 01:02:08 AM »
Dave and Steve,
  Many thanks  for you good advise  !! 
   I spent today cleaning the radiators. I undid the securing bolts on the external grill/panel so I could get in there.
    There was an amazing amount of junk,a rag and many pine needles etc in the tray bottom between the radiators.
     I used ac coil cleaner and thoroughly rinsed both rads.
     Next week we will flush and refill with Cat ELC coolant and change the filter.   
     If my C12 is rated for 10,007 feet and Vail Pass is 10,500 ft should I attempt it or find an alternative route to get to The Arches National Park etc and Moab ????  I am towing a 2004 F250 6.0 King Ranch.  it

Dave Atherton

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Re: Running at higher elevations.
« Reply #5 on: September 28, 2015, 01:50:50 AM »
Jeremy, you will not have any problem pulling pickup over vail pass on I-70. Just remember when
You see big trucks climbing slow with 4-ways flashers on you will be going slow also, this is the nature
of the beast. Would also suggest there are many 6 to 9 percent grades going down for many miles at a
time. Remember to gear down and go easy with brakes and heavy use of engine retarder when going
down long grades. Check weather for vail pass they had snow last thurs and thing can get real messy
with ice at tunnel. Depending on weather ( weather can change real quick high up on I-70 ) plan B
You can go south on I-25 and get on I-40 to Gallop, MN than go north to Moab, Ut.  Dave Atherton

Lee Welbanks

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Re: Running at higher elevations.
« Reply #6 on: September 28, 2015, 02:31:51 AM »
Jeremy,

On I-70 you go up and through the Eisenhower tunnel (11,155 ft) and you will not have any problem, it is actually a steeper grade (7%) the first pull coming west of Golden, I have been on it a couple times got down to 45-50 in 4th gear, run down the west side in 4th sitting on the engine brake and only touch the brakes once or twice.