An idea for an external CVT cooler

[Teasmade]

As we all know the CVT cooler on our cars is the standard Jatco effort - A lump of alloy that both engine coolant and CVT fluid flow though in separate channels. The coolant helps warm the CVT fluid on cold starts and, once the fluid is hot, it then dumps heat into the engine coolant.

I'm not sure if we've yet had a heat related failure on here but the Nissan Juke forums are full of people complaining about whining CVTs and worse after a long journey and in the UK, the Juke CVT is developing a reputation for premature failure. The key relevance here is that a number of Juke CVTs use the RE0F11a transmission - AKA the Jatco JF015E, AKA the Mitsubishi F1CJB as fitted to our beloved Mirages.

Obviously the Juke is a heavier vehicle and has more powerful engines - and therefore will put more heat stress on the transmission, but I can imagine that Mirages used in 'severe' circumstances could start to overwhelm the factory CVT cooler. Having read several owner experiences, it seems that adding an external air-fluid cooler to take more heat out of the engine coolant before it passes through the CVT cooler is ineffective, but someone on Ebay appears to have come up with a solution. They don't appear to be selling these any more, but I know we've got a few CNC / Fabricator people on here.... So what do you think of this?

http://www.ebay.com/itm/-/271960306676

[inuvik]

We have a few members that are running ScanGuages so it would be interesting to get some feedback on transmission temperatures that they are seeing. Extra cooling never hurts but I'm wondering that since the Mirage is only 74 or 78 hp and it only weighs 2k if there is really that much stress on the CVT. At GVWR the Mirage weighs less than the curb weight of the Juke.

[Angrybeaver]

I'm also curious if anyone has installed an auxiliary CVT cooler.

[Teasmade]

Getting extra data would be interesting, yes. I have a bluetooth OBD adapter and Torque. Unfortunately the CVT temperature isn't one of the standard codes (There is a trans temp available but it's the generic 'calculated' one and it just follows the coolant temperature readouts exactly, which isn't particularly helpful).

There is a addon for Torque called 'Advanced EX for Mitsubishi', which adds in a lot of Mitsu-specific data, but I've not tried this yet.

[cyclopathic]

On Torque: if you know/find out PID for temp you can add it manually.

Never tried though personally

[cyclopathic]

on OP: how about instead putting an additional cooler, just helping existing one to work better? For example Watter wetter in coolant, better synthetic oil in CVT, magnetic plug to keep contamination lower?

[Cleartec]

on OP: how about instead putting an additional cooler, just helping existing one to work better? For example Watter wetter in coolant, better synthetic oil in CVT, magnetic plug to keep contamination lower?

I like how you make seem so simple, so thanks But is there any proof that synthetic cvt oil is better than OEM synthetic cvt oil?

[Teasmade]

on OP: how about instead putting an additional cooler, just helping existing one to work better? For example Watter wetter in coolant, better synthetic oil in CVT, magnetic plug to keep contamination lower?

Certainly a high-spec CVT fluid would not degrade with heat so readily, but then... Do we know that CVTF-J4 (AKA Nissan NS-3) is not a synthetic fluid already?

Magnetic plug - Maybe, but surely the internal gearbox filter would trap any such particles?

As for water wetter... Mixed reviews on the 'net, with most suggesting around 5~10 Fahrenheit temperature differential. So yeah - could help a *bit*, but I'm thinking of long, hilly journeys where a CVT can get really hot and bothered. Even with Water Wetter installed, I don't think it would improve the heat rejection enough to prevent overheating.

Of course, without data on exactly what temperatures the CVT fluid reaches during normal, gentle and severe operation, it is difficult to say. Must find those PID codes!

[man114]

I was looking into this too, but I think a lot of the Nissan problems are unlikely to present themselves in the Mirage. The Mirage has a much cleaner engine bay so it will have better air flow and less circulation. It's a lighter car with less torque and HP. Additionally Mitsubishi has a long warranty anyway on the drivetrain.

[Teasmade]

I largely agree with your sentiments, Man114 - Apart from the drivetrain warranty - 3 years in the UK is all we get, I'm afraid.

I gather Euro-spec Jukes may have a air-fluid cooler as well as the 'Beehive' on the end of the gearbox. I'll see if I can get to peer under their bonnet to confirm - as that might represent a bolt-on solution.