19-20 Discussion on Missing Ambient Cooler

I wanted to start this thread to debate the missing ambient cooler on the 2019 and 2020 Tundra's. Post your experiences running your 19 and 20 trucks without a cooler and if you think it's an issue. If you installed the cooler or have an older truck with the cooler your information can also be helpful. I think the thread could be a good source of information.

I tow a Coachman 204RD with a loaded weight between 5-5.5K with my 2020 DC 4X4. I had a high temp of around 240F on slightly challenging trip. I'm planning a trip to the Rockies and was concerned that on the steep grades I would see temps above 250F so decided to put the aux cooler on using Toyota parts and a

$52 Hayden 679 Universal 11” Rapid-Cool Add-On Transmission Cooler to Enhance Cooling (not for direct replacement of the factory unit)

Hayden 679 cooler. I immediately noticed a temp drop without towing of around 25F. My trip will start next week and will see how the cooler does in mountains.

Temps while towing


Cooler installed

 

Thanks for starting this thread. I'm also interested though I don't tow very often. I live on the gulf coast where it is HOT and HUMID for most of the year. I'm concerned about the heat just because of where I live.

 

I would start with getting the Fussion app and an obd2 dongle and seeing what temperature your transmission is running. There's lots of opinion on what an acceptable temp and you will have to decide for yourself. Unfortunately Toyota is pretty quiet on what's normal. Personally I think temps above 230F for the pan are consideration for a cooler.

 

I have a ScanGaugeII that I got in 2006 or 2007. I am sending it in for a firmware upgrade. Hopefully I will be able to configure it to see these temps. We'll know in a couple of weeks.

 

I have a 2018 4x4 crewcab and a 2018 Mallard M28 w/ a weight of about 7000. I towed from Miami to Fayetteville NC and highest I saw was 224 or so. Factory cooler on mine.

 

Was that Transmission Pan temp or Torque Converter temp? Thanks!

 

Honestly can't recall. I use the Fusion app as well. They were close to each other though.

 

Ruggybuggy thanks for the good thread and fantastic information on these trucks.

So here is my experience...

In West Texas Summers, 100-105 ambients, and 3300-3600 elevation (thin-ish air), I am getting 225-230 pan temperatures. This is running the truck hard: not towing but hot lapping the truck like I was trying to break it in half. 0-90 runs between 4-7 times in a row, less than 6-7 minutes between runs. The West Texas freeways have small turn arounds about 1/2 mile apart. So I could run the truck super hard.

This got me 225-230 pan temps and 250 TC temps.

I put a heater core for a Chevy van (large...approaching size of a sport bike radiator) in line between factory Tundra heater core and the hockey puck cooler/warmer.

The results:

Took WAY longer to warm up.
Seemed to cool off a bit quicker. Meaning when pan temps hit 230, they would cool off to 215-218 a bit faster (when going 78 mph speeds)

I took off this heater core and replaced the factory hose and retested. It warmed up quicker but I couldn't realistically claim it moved the needle.

I ran same tests as above and got same results. Seems like when running the truck really hard pan temps stubbornly refuse to go above 230-232 F.

The puck warmer/cooler is doing something but I'd like to see something like 210F.

When cruising I don't see temps above 215.

Engine coolant temps with or without the additional heater core were really steady and never once went above 204.

Next experiment: Going to try insulating the puck from the catalytic converter and exhaust temps.

Trying to see if there is any cheap, easy, ways to drop temps 5-10F.

I've had luck with this getting a ridiculously weak S197 mustang air conditioning system to cool better.

Other research experience:

I have firm understanding from a major lube oil OEM ( a contact through my regular day job) that 1) WS fluid is a group 3 oil. 2) Group 3 oils perform as well as full synthetic PAOs up to and a bit beyond 300F.

...and other items...3) Ram trucks are going up to 240-250 on engine oil temps with no issue and a fraction of the sword-falling. 4) Shift strategy, and rear gearing can have a tremendous impact on trans temps.

 

Can someone who uses torque pro check my pids here? I have checked on this site but everything I found for torque pro is for the older tundras. Is it the same for the other OBD2 apps?

 

I use to run Torque that worked great on my 18 Tacoma but could never get it to work properly for my 20 Tundra. I gave up and now use Fussion and bought the upgrade. It was pretty cheap.

Maybe someone has had better luck with Torque and will respond.

 

So i did a little experiment yesterday. Drove my truck empty, then with 1800lb utility trailer nothing in it. Then with a 1600lb rzr on it.

Ambient temps 99 to 101 degrees
20 miles freeway at 70mph
Tow haul mode on when towing tranny in D

Empty -trans pan and converter temps 212 steady.

Trailer only hit 218 if i i nail it to pass someone and temps rose 2 or 3 degrees they would then drop to 218 within a minute.

Same trip with rzr on the trailer went to 230 degrees pan and converter dead steady the same. Here is a pic i took with trailer loaded as i i t off freeway and slowed down to 45 temps started dropping within a minute. Slower speed cooler the tranny.
I also tried s4 and s5 made zero difference.

this is the extent of what i tow so i dont think this is a problem for me.

 

I think you will be fine also but I would do a service earlier than normal to just have a look at the color of the WS.

 

ill be taking it on an 8 hr trip with the sxs on trailer end of October ill report if temps get much worse on that long a trip. although the air temps by then wont be a 100 degrees.

 

I'm using an Android phone and it's fairly easy to use with a slight learning curve. Others have used Fussion on their iPhones.

 

I just received mine yesterday. The setup (iPhone X) was very straightforward and went smoothly. It communicates with your phone through Wifi. That said, I have A LOT more to learn because there are almost 2000 data points this OBD reader can read!

 

@Ruggybuggy have you taken that trip through the rockies yet? curious on the temps you see.

 

I leave tomorrow but won't hit the Rockies until Monday.

 

sounds good. be safe.

 

Ya be careful, there’s people like me out there.

 

I am running Torque Pro on my 2018. Unless they are different on a 2020, trying using A and B instead of E and F, and C and D instead of G and H.

 

These are Aisin transmissions. As long as you don't hit 280 you're good. The trans oil cooler drama is a joke.

 

I've got bear spray for guys like you.

 

Guys have gone past 302f.

 

This one:
https://www.tundras.com/threads/whats-your-latest-purchase.15042/page-179#post-1882607

 

Following , good info.

 

Update.

Added some insulating tape to the puck and as much of the metal coolant lines as I could get to.

Results aren't earth shattering. However I noticed the following:

I had to run the truck insanely hard in 103-104 F temps to hit the 226-28 pan temp threshold.

I hit 232-233 after running for a long time at 85, some stop and go, and then 4 straight 0-95 mph runs.

Then after 2-3 0-80mph runs, the pan temps refused, refused, to budge above 232F. Coolant temps hit 204.

At this point I quit trying to break the truck in half. Lol Tundra fuel mileage...gas gauge moved 1/8 during this.

I also noticed that at higher engine speeds, coolant temps drop fast down to 195F, and the pan temps responded quickly. I hadn't seen this before.

My conclusion is that heat is getting into the puck from the catalytic converter and exhaust pipe being close. With the insulation the coolant can remove a bit more heat and cool the system down a bit faster.

 

Do you have any photos of where you applied the insulating tape? That’s awesome

 

I wonder if over a long period of driving if this would work in the opposite direction. It seems like anyway you can shed heat the better and maybe it would be best to only insulate the input and not the output

 

Hook up a heavy trailer, climb a hill and get back to us.

 

No joke...I would still feel a bit uncomfortable towing in high ambient temps