Some Like it Hot (or not?)

[Ale Vallecchi]

As off-road driving slowly resumes, we find ourselves facing conditions which are increasingly challenging. You all must have noticed refusals and stucks, in places where you would not have had any problems driving through before the lockdown. We all know the culprit: the HEAT!!

While in its grasp, the heat is making us rethink how we should drive.

What tips should we follow, and what changes should we make to our driving style, during the summer months (especially now, when the curfew is still on, and night-time drives are out of the question)?

Hints:

• tyre pressure
• speed and momentum
• angles of approach
• gauge reading
• what NOT to do

Throw in your opinions, share your experiences, give your tips to more junior drivers.

[Frederic]

Very good topic @Ale Vallecchi

I have a digital readout engine temp gauge which allows me to constantly monitor my engine temperature. During driving, my temperatures remain acceptable, but during idling, especially with the AC on, the gauge slowly creeps up to about 105°C. From that moment onwards i generally reduce or switch off the AC for a while, and increase my idling speed a bit by pressing the pedal. This makes the fan run a bit faster, and i keep doing this until i am back at around 92°C.

Driving in the desert at this heat requires slightly different approach, you need to use the momentum that the dune gives you to make it over the next one, drive higher on the top of the dunes so your car can breathe better, and never take the car beyond its limits. 

Deflating further down to 11-12 psi definitely helps too, and verifiying after 1.5-2 hours of driving because the pressure will have built up again due to the heat.

[Ale Vallecchi]

Thanks @Frederic for your tips.

As far as over-heating, I guess a lot depends on the car. I understand Jeeps, and perhaps Pajeros may suffer the heat more than other cars.

As far as deflating, I believe one may deflate even lower than 12 or 11, depending on the tyres she/he's mounting. Mine are quite high rimmed, and I usually like deflating down to 10, or even 9 PSI. In which case, one must be even more careful with pop-outs.

I surely like to drive higher on the dunes, especially for crossing over. I believe that's especially true for long-wheel based cars, which tend to be dragged down by their own weight, when approaching the crest from too far down, and at a sharper angle.

 

[paolo dassi]

Just to put down some numbers (sorry I am an engineer 🙄) I deflated yesterday morning to 13psi @ about 7am, while I read 15psi for aft tyres and up to 15.5 in the front ones at 10:30 when we got to Al Qudra last exit... Definitely something to bear in mind!

Other point, yesterday I found quite a bit of sand stuck on the radiator: this decreases substantially its capacity of dissipating heat. Even if you do not wash your car often (I don't!) some parts might need your attention in hot environment.

Edited June 6, 2020 by paolo dassi

[desertdude]

It's not the heat of the engine that is giving you this issue. It's the dryness of the sand. As the weather gets hotter that sand dries out losing most of it's moisture content, making it more soft, powdery and fluid.

Even in summer. On a humid foggy morning you'll be able to drive better but as the day progresses, water evaporates it'll start to get more difficult.

A heat soaked motor will lose some top end power but not that much that it effects it performance so notably.

But that's true if any dune bashing drive in any weather

[Ale Vallecchi]

8 hours ago, paolo dassi said:

Just to put down some numbers (sorry I am an engineer 🙄) I deflated yesterday morning to 13psi @ about 7am, while I read 15psi for aft tyres and up to 15.5 in the front ones at 10:30 when we got to Al Qudra last exit... Definitely something to bear in mind!

Other point, yesterday I found quite a bit of sand stuck on the radiator: this decreases substantially its capacity of dissipating heat. Even if you do not wash your car often (I don't!) some parts might need your attention in hot environment.

Good points @paolo dassi.

Tyres do re-inflate as the drive progresses. Especially if some more challanging, taller or steeper dunes, requiring more traction, are to be found toward the end (especially of a morning drive), pressure must be checked, to deflate again if necessary. 

I usually have the car washed underneath and in the engine bay, to get rid of the sand, every max 3 drives. Mine was just a generic precaution, but as you mentioned, in the summer it will likely help to improve the flow of air through the radiator.

 

[Fuad]

1.Always check all fluids before heading to Desert

2.If anything covering the passage of Air to radiator remove it.

3.Keep the radiator clean (Atleast use water to clean it after a drive)

4.Always keep a sprayer with water in vehicle.

5.Finally a big big no. “When ever the temp gauge start rising - Be cautious ,Monitor constantly, when its beyond the level announce on the radio and immediately stop the vehicle for assistance”

6. Use the heater to dissipate heat instantly.

7.Never take car to extreme level if you have any trouble with machine as we are testing the maximum output.

8.Never Open radiator cap and pour coolant immediately after engine heats up.(it will kill it).

”This is the Mistake everyone commits”

just my few cents . 
 

[paolo dassi]

10 hours ago, Fuad said:

8.Never Open radiator cap and pour coolant immediately after engine heats up.(it will kill it).

Very good point, it will kill it and likely injure you! Opening the tap releases the high pressure of the circuit, coolant might come out (either in liquid or vapour form) being extremely hot and burn your hand / arm... not very pleasant!

[Ale Vallecchi]

11 hours ago, Fuad said:

1.Always check all fluids before heading to Desert

2.If anything covering the passage of Air to radiator remove it.

3.Keep the radiator clean (Atleast use water to clean it after a drive)

4.Always keep a sprayer with water in vehicle.

5.Finally a big big no. “When ever the temp gauge start rising - Be cautious ,Monitor constantly, when its beyond the level announce on the radio and immediately stop the vehicle for assistance”

6. Use the heater to dissipate heat instantly.

7.Never take car to extreme level if you have any trouble with machine as we are testing the maximum output.

8.Never Open radiator cap and pour coolant immediately after engine heats up.(it will kill it).

”This is the Mistake everyone commits”

just my few cents . 
 

Well said and appropriately stressed.

I am realizing during these last drives how many over-heating problems there have been, and how easy it is to forget to check the gauges (especially for more junior drivers, while being busy navigating, and perhaps looking at beautiful landscapes).

Maintenance and cleanliness of the radiator (and other engine parts) perhaps is not stressed enough, but I find it is something we all should become accustomed to, and practice regularly after each drive.

Thanks for the great tips.

[Denizzalbayrak]

Having one overheating experience will change you forever. I check heat gauges constantly now, even when I'm on the passanger seat. experimental lessons are impossible to forget.