Driving diesel in very HOT temps - 103+ and long grades

[catkins]

OK - new to me issue of excessive temps in the NW and needing to drive from Seattle to Spokane over Snoqualmie Pass and through the Vantage grade.(lots of long grades up and down) Temps are expected to top out at 105 the day I must drive. Looking for what I need to do to avoid potential overheating. Driving a 36' Tiffin RED with a Cummins engine and Allison transmission.

I am assuming downshift to raise the RPMs to ??? and go slower to avoid overheating if engine temp is climbing. Yes?? Going to NOT pull the TOAD in that heat up those grades as my diesel is only a 340 and doesn't like the pass on a good day with the Toad attached. Any other suggestions/must dos?

Thanks - I know the truckers do it all the time. Just seeking to avoid stressing my equipment unnecessarily.

[ScottG]

Not only is the area through Vantage steep and hot, sometimes it has sustained severe headwinds the whole way. It can be one brutal drive!
Still, I'm envious of your trip. Best of luck to you!

[catkins]

dubdub07 wrote:
I have a hard time believing it will be 105 degrees at the top of a mountain pass in the west. Looking at the record high of 101 even seems amazing. I bet at the top it will only be 80s or 90s and the pass info on Mr. Internet says it is only 2 miles of steep at the top around 7%. I drive the CO mountain passes, most of them, in the summer that are 7-9% for miles and miles and see no heat problems. My tranny is around 201F and my engine gets up to a whopping 205F. Not high enough to worry...

WW

Correct but after the pass weforge into Eastern WA to Moses Lake area with the Vantage grade before we arrive. Projected temps are 105 for Thursday. Trying to go early to avoid mid afternoon heat. Simply looking for proper way to react IF I encounter overheating. Engine heats to 212 and fan kicks in, tranny temps climb as well.

Thanks to all for input.

[dubdub07]

I have a hard time believing it will be 105 degrees at the top of a mountain pass in the west. Looking at the record high of 101 even seems amazing. I bet at the top it will only be 80s or 90s and the pass info on Mr. Internet says it is only 2 miles of steep at the top around 7%. I drive the CO mountain passes, most of them, in the summer that are 7-9% for miles and miles and see no heat problems. My tranny is around 201F and my engine gets up to a whopping 205F. Not high enough to worry...

WW

[wolfe10]

hotjag1 wrote:
If you haven't cleaned(washed) your radiator within the last 6 months, I would really recommend that you do that before your trip.

Just to clarify, cleaning the radiator (the thing you see from the back of a rear radiator coach) is NOT where most of the dirt will be found.

It will be on the FRONT of the CAC, as that is the first thing in the air flow and "filters" out most of the dirt before it reaches the radiator.

[hotjag1]

If you haven't cleaned(washed) your radiator within the last 6 months, I would really recommend that you do that before your trip.

I clean ours every 6 months and recently went east in 100+ temps and the temp guage never got past 205 degrees and that was going up through the Bighorn mountains at over 10,000'.

These engines kick up a lot of dust when going down the road and I think frequent cleaning is a must for keeping the engine running at safe temps JMO.

[2oldman]

ScottG wrote:

2oldman wrote:
You can't go earlier?

I once left a park at 1:30AM to avoid the heat of the day!

I've never left quite that early, but the crack of dawn around 5 works - try to get off the road by noon. Do not like 90+ temps driving, neither do my tires.

[flagstickfrank]

Just drove the same route (Seattle to San Diego) last week in a 36' DP,
300 hp CAT pulling a Honda. No problems and the outside temp. was 100+ most of the way. I did downshift to keep revs at or near 2000, the heat gauge didn't get above midway. Secret is don't get in a hurry and use your flashers below 45 mph. Just sit back and enjoy the scenery, it's beautiful.

[wolfe10]

ScottG wrote:

2oldman wrote:
You can't go earlier?

I once left a park at 1:30AM to avoid the heat of the day!

Yup, did that the last time from Kingman to Bakersfield mid summer.

[ScottG]

2oldman wrote:
You can't go earlier?

I once left a park at 1:30AM to avoid the heat of the day!

[dkreuzen]

I live in an area where the summer daily high temperature is 100-125 and I come and go in that heat. I haven't had any heating issues with any of my last three motorhomes and I don't bother doing anything special but do keep an eye on the temperature gauge just in case. As long as your cooling system is working correctly you shouldn't have a problem.

[longdrive]

Just drove the southwest late July with same heating issues. 350 Cat. Spray off your radiator before you leave. Mine worked best at about 2,000 rpm, keep down shifting. I had to hit 1st gear a few times, about 20 mph, turn your flashers on and drive slow. To cool down if needed pull over and rev the engine and your temp will come down then.

[catkins]

2oldman wrote:
You can't go earlier?

We will leave as early as we can to try and avoid some of the heat but those grades and rising heat are concerning me. We will not be driving in the absolute peak of the day's heat but it will be plenty hot as we approach our destination and the last big grade.

[2oldman]

You can't go earlier?

[path1]

On grades I drive by egt's and keep eye on all temps. Mine is Cummins and i dont go over 1200 on egt's. Not sure about cat. Dont forget to also cool down turbo before shut off. And dont stop at top once you make the top, keep going to cool stuff down. Things should work as designed. If overheats something not right. I think vantage hill is worse going west bound with headwind. Good shop in Quincy, doesn't take advantage of freeway traffic. I fuel at mile marker 101 Ellensberg I think. Vantage...not much and middle of nowhere, so to speak. You got cell service though.