Secondary 12vdc fan for hot running engine on 2013 Mega cab ......

[Newsa]

Diesels run get more power when they get good & hot. And they burn cleaner with less soot. IMHO

 

[sag2]

Mine is a gas Hemi 8 speed, but just to give another take on temps we just finished an 1800 mile trip towing 5k and the coolant averages 220, trans 195, and oil up to 260 on long pills. Also interesting is trans temp would climb to 210'ish on long pulls in the same gear all the way up. I'm surmising the converter in the 8 speed never fully locks just like the old NAG's did. Scan tool does not show converter slip.

 

[Bug Out]

sag2, like I said before, I am comparing it to my two previous RAMs that I bought new. I have resigned myself to letting this thing run as hot as it wants, maybe it will start triggering CEL's or burn up. Then the techs will have a code to work with.

 

[RustyJC]

On the flat Interstate at 65 MPH on a 95-100 degF ambient day, mine runs about 203 degF coolant temperature with 172 degF transmission temperature towing our 5th wheel (19K GVWR). On long pulls, the coolant temperature will rise to 221 degF where the coolant fan fully engages and pulls the coolant temperature back down to around 210 degF before disengaging; the coolant temperature will cycle between 210 and 221 degF until the road flattens out again. Transmission temperatures might rise to 180 - 185 degF or so as it cycles between 5th and 6th gears.

The only time I've seen transmission temperatures above 200 degF when towing are in long periods of stop-and-go traffic, on a long uphill grade with switchback turns that kept the transmission in 1st and 2nd gears, and using the exhaust brake at low speeds coming down a long grade, manually shifting into 1st & 2nd - I saw 235 degF briefly during the latter but never got a high transmission temperature light!! Apparently the exhaust brake function of the VGT will continue to work even if the torque converter isn't locked up in these conditions, which I find surprising. (Yes, it was in tow/haul mode, but being manually shifted with the +/- switch.)

Rusty

 

[Bug Out]

RustyJC, that about how my first two ran. If the trannys got hot, the temp would drop fast once on level ground. This one, engine 210-215 average towing, and can go up to 224 without clutch fan engaging, transmission hovers around 200 and above climbs on hills, unlike the last two. This thing is its own animal. I got a few more years to pay down on the RV and I might just throw the towel in completely.

 

[Ozymandias]

The only time I've seen transmission temperatures above 200 degF when towing are in long periods of stop-and-go traffic, on a long uphill grade with switchback turns that kept the transmission in 1st and 2nd gears, and using the exhaust brake at low speeds coming down a long grade, manually shifting into 1st & 2nd - I saw 235 degF briefly during the latter but never got a high transmission temperature light!! Apparently the exhaust brake function of the VGT will continue to work even if the torque converter isn't locked up in these conditions, which I find surprising. (Yes, it was in tow/haul mode, but being manually shifted with the +/- switch.)

Rusty

That surprises me too, the my old ***** with its 48RE has second gear lockup when set manual to 2nd Gear.

 

[RustyJC]

That surprises me too, the my old ***** with its 48RE has second gear lockup when set manual to 2nd Gear.

Suffice it to say that I certainly wasn't expecting to see the transmission temp that high when I glanced down at the EVIC!!! I'd already done the uphill stuff without incident and was on the downhill side when the transmission fluid temperatures rose to 235 degF.

Rusty