Very Hot Weather Operations

[63Hotrod]

Headed to Yuma/Tucson where temps are 110 plus. Concerned what that will do to engine temp

[Rikadoo]

Engine temp is for the most part a controllable issue provided you have done your part to ensure the engine has what it needs to succeed.

Having a good 50/50 balance of coolant, a good functioning, coolant pressure cap, unrestricted air flow thru the radiator, AND if you have a fan clutch that it is functioning as designed. Now other factors that are relevant, a radiator that is not consumed with internal restrictions, such as solder bloom, loose fan belts, or powertrain issues (transmission slippage) or overloaded vehicle.

Frankly i would be MORE concerned about blow outs, or generator failure (from running the roof airs while traveling in that heat)

To be sure high heat is very much a real concern, and that automotive cooling systems perform the same be it a small horsepower automobile or a locomotive, there jobs are to remove heat, and if your cooling system is compromised by any of the above issues, you will possably have a problem. 
Consider this, as your going down the hiway look around, are the truckers still driving(pulling loads up to 80 k Lbs) newer cars still traveling? Consider what you dont see, old unmaintained vehicles that not been well maintained, or vehicles with old bald tires. 
I dont wish to diminish your question at all, in fact its a very honest question, however its one that begs the question, if in fact your concern is “can my cooling system deal with the heat?” Then the answer in my estimation is, “what shape is my cooling system in? “
As always in extream heat OR cold know your level of maintenance, then like the motto of the Boy Scouts… Be Prepared! 
 

[waterskier_1]

Agree with Rik's comments.  Especially the generator when driving.  I've read several reports where, depending on the specific coach, the generator doesn't get proper air flow when going down the highway.  They weren't really designed to take advantage of the "forced air" and in some cases, the air is forced around the generator radiator.  It would be nice if we had a temp gauge for the generator in these cases.  

The other concern is once you are there, does the park have sufficient 50 Amp Shore Power such that it doesn't drop significantly when all the other RVs are running their A/Cs.  I had that problem at a park this spring.  Many of the trailer and coaches were only 30-Amp units with single A/Cs.  I'm not sure how they wired the park, but clearly most of those ended up on the same leg, as it would sag below 95 volts at dinner time.  They called an Electrician out, but there really wasn't anything he could do.  He couldn't raise the voltage at the transformer, because the no-load, or minimum load voltage was already at 125+ Volts.  The problem was either too small wiring conductors to the pedestals, too many pedestals on each circuit (run), or, most likely, both.  My surge protector shut down my shore power several times.  Decreasing my load didn't make much difference, because everyone else was running large loads (A/Cs and microwave or electric cooktops/skillets).  

Have fun - you'll likely be running between an A/C'ed coach to an A/C'ed Car to and A/C'ed building.  

  -Rick N.

[vito.a]

Travel at night or very early morning.  Sometimes we carry a garden sprayer full of water.  If engine or generator heats ups, spray the appropriate radiator.  

[timaz996]

I lived in Phoenix when I bought my coach. If you don't have temp problems pulling steep grades then you should be good.

[Tom Cherry]

On 7/16/2023 at 12:47 PM, waterskier_1 said:

Agree with Rik's comments.  Especially the generator when driving.  I've read several reports where, depending on the specific coach, the generator doesn't get proper air flow when going down the highway.  They weren't really designed to take advantage of the "forced air" and in some cases, the air is forced around the generator radiator.  It would be nice if we had a temp gauge for the generator in these cases.  

The other concern is once you are there, does the park have sufficient 50 Amp Shore Power such that it doesn't drop significantly when all the other RVs are running their A/Cs.  I had that problem at a park this spring.  Many of the trailer and coaches were only 30-Amp units with single A/Cs.  I'm not sure how they wired the park, but clearly most of those ended up on the same leg, as it would sag below 95 volts at dinner time.  They called an Electrician out, but there really wasn't anything he could do.  He couldn't raise the voltage at the transformer, because the no-load, or minimum load voltage was already at 125+ Volts.  The problem was either too small wiring conductors to the pedestals, too many pedestals on each circuit (run), or, most likely, both.  My surge protector shut down my shore power several times.  Decreasing my load didn't make much difference, because everyone else was running large loads (A/Cs and microwave or electric cooktops/skillets).  

Have fun - you'll likely be running between an A/C'ed coach to an A/C'ed Car to and A/C'ed building.  

  -Rick N.

Ditto to RIK & RICK.

COUPLE of comments.  I climbed into and descended out of Sequoia NP from the west side.  Hot as blazes.  Kept an evil eye on the tranny gauge.  The Transynd is good for something like 250 deg F, for the shifter solenoids or such, read up on it…but Allison said that as long as you did not exceed 225 - 230 deg F or so…OK.  They DID says to downshift or “let off on the accelerator when climbing” if the Tranny got much above 215 Df and get the engine revs up to supply enough coolant to the tranny as well.  I think my Allison was rising above 210 which was consistently higher than regular driving...and I downshifted and pulled over to let folks pass.  I later called Allison and they verified.  I DID listen at a Gathering session.  LOL.  Same deal….watch the Tranny temp in downshift mode.  Mine will run higher….think about the differential.  I switched to Delvac Synthetic for that reason…plus others.

If you don't have an Aladdin or an AC meter, use your VOM and check inverter (usually Line/Leg 2) And find a place to measure line 1.  There are tons of 30 A TT and when itbgets hot and the CG wasn’t wired properly, your voltage can be under 100.  Not good.  I have moved 3 times, based on my Progressive HW50C meter and killed the 50 A and ran the Generator until after dark.  My HW50C was cycling on and off….not good for an AC.

[David K]

1 hour ago, Tom Cherry said:

Ditto to RIK & RICK.

COUPLE of comments.  I climbed into and descended out of Sequoia NP from the west side.  Hot as blazes.  Keep an evil eye on the tranny gauge.  The Transynd is good for something like 130 deg F or so.  Allison says to downshift and get the engine revs up to supply enough coolant to the tranny as well.  I think my Allison was rising above 120….and in downshifted and pulled over to let folks pass.  I later called Allison and they verified.  I DID listen at a Gathering session.  LOL.  Same deal….watch the Tranny temp in downshift mode.  Mine will run higher….think about the differential.  I switched to Delvac Synthetic for that reason…plus others.

If you don't have an Aladdin or an AC meter, use your VOM and check inverter (usually Line/Leg 2) And find a place to measure line 1.  There are tons of 30 A TT and when itbgets hot and the CG wasn’t wired properly, your voltage can be under 100.  Not good.  I have moved 3 times, based on my Progressive HW50C meter and killed the 50 A and ran the Generator until after dark.  My HW50C was cycling on and off….not good for an AC.

A couple of years ago we traveled through Needles, CA in August (daytime temperature 115F plus) and climbed up to Kingman, AZ (nearly 104F that day in the late afternoon) using Rik, Tom, and Vito's input.  We would leave around 3 a.m. and shut down by noon carefully monitoring engine and transmission temperatures.  Honestly, tire blowouts were our biggest concern (Rik's comment).  We did just fine.  

[Bill R]

1 hour ago, Tom Cherry said:

The Transynd is good for something like 130 deg F or so.

@Tom Cherry  Did you mean 230F?  I may be misinterpreting your comment or misunderstanding the application you are referencing.   My Tranny temp runs almost in line with the engine coolant temp.  190F-200F.  That is because the transmission cooler is air cooled and is mounted below the engine and is cooled by the side radiator fan exhaust.  

This is from from Transynd 668 product brochure.  

 

Like all transmission fluids, TranSynd is best when it’s temperature is between 160-200 degrees F. This common range is best for longevity of both your transmission fluid and transmission itself.  The below transmission fluid chart shows how long transmissions last when fluid reaches various temperatures.

[Happycarz]

I live in the Phoenix area and often leave town with temperature 110°-115° and climb 6% grade for 1 ¾ hours before seeing 105°. I run my generator and both roof airs the whole time. I turn off the dash a/c if I remember on the 6% climbs, but if not my engine temp might hit 205°

On my previous coach I used Fleetguard ES Cpompleat EG, the blue stuff that requires you to test the SCA, and changed it every two years, just a drain and fill. At 90,000 miles I removed my radiator stack to send out the CAC for repair. While the radiator was out, I looked in at the core. No solder bloom, just nice and clean.

 On my next coach, my current Camelot, I returned to the factory for warranty work when it was 10 months old . At the time I asked what coolant was Monaco now using, as it was green. They pointed to a 55 ga barrel with some nondescript label on it. So, at 18 months I did a drain and fill, using the robust Fleetguard ES Cpompleat EG.  It work so well with my last coach, I decided to continue with the same regiment. 

When OAT coolants were first introduced in the nineties, there were some growing pains with them. I didn’t want to be part of the beta coolant testing program! (My words for it.) I thought for $100 investment every two years I could keep my cooling system in tip top condition. Now with 86,000 miles on the coach, I still have a pristine cooling system, and no cooling issues. I replaced the hoses when 10 years old. I do a yearly exterior cleaning of the radiator, CAC and a/c condenser.  I’ve replaced the belts twice, tensioner once. In other words, I do preventative maintenance to the fullest.

With all that said, I feel confident to get in it at anytime and head out, regardless of the temperature   The coolant temperature is no issue. Running the generator is no issue, even at 115°  The PM on it is done religiously, too.

To answer Bill’s question about his trip to Tucson/Yuma, you should have no issues if your cooling system has been properly maintained. Just carry spare hoses, coolant, and belts. If any cooling system maintenance is due, git ‘er dun, before heading out. It is no fun breaking down. It can get expensive rather quickly, and ruin a trip.

With your rear radiator coach, you have a tougher time replacing items than folks with a side radiator coach. PM is a must. Make sure you are current with your maintenance on both the engine and the generator before you leave home. Then, pack up, head out and enjoy your trip. Make memories.

[jacwjames]

22 minutes ago, Bill R said:

@Tom Cherry  Did you mean 230F?  I may be misinterpreting your comment or misunderstanding the application you are referencing.   My Tranny temp runs almost in line with the engine coolant temp.  190F-200F.  That is because the transmission cooler is air cooled and is mounted below the engine and is cooled by the side radiator fan exhaust.  

This is from from Transynd 668 product brochure.  

 

Like all transmission fluids, TranSynd is best when it’s temperature is between 160-200 degrees F. This common range is best for longevity of both your transmission fluid and transmission itself.  The below transmission fluid chart shows how long transmissions last when fluid reaches various temperatures.

First time I'd seen this graph/chart. 

Confirms my decision to add a secondary transmission cooler after installing a CG&J radiator and getting transmission temps +230F.  After installing the cooler my tranny runs cooler then engine and it gets to ~178F will cool right back down after cresting grade etc. 

 

 Another member was going to add a cooler but the Allison shop would not do it saying 250F temps were just fine and dandy. 

[Robert92867]

I Stayed in Mesquite Nv. overnight on Tuesday (July 18) temps were 113.  Wedneday I crossed thru Las Vegas (110).  Major traffic and accidents. I spent 1/2 hour creeping along, watching my engine temp rise to 200, and trans went up to 210.  Hemmed in on all sides by big rigs, all pouring out massive heat. Every year since 2010 I pull my CAC and fan (rear radiator model) and pressure wash the radiator to sparkling clean from the inside.  Maintenance pays off. I've got it down to under 1 hour to pull both.