When it overheats you'll usually hear a screaming noise from the transmission. If you hear that you know you've overheated the CVT and the fluid is essentially ruined.
Obviously you've got to solve the overheating problem but for those who don't know, it is essential to change the CVT fluid at least every 50,000 miles -- some say even more frequently.
When it overheats you'll usually hear a screaming noise from the transmission. If you hear that you know you've overheated the CVT and the fluid is essentially ruined.
Obviously you've got to solve the overheating problem but for those who don't know, it is essential to change the CVT fluid at least every 50,000 miles -- some say even more frequently.
The modern full synthetics can take quite a lot of abuse if temp is kept under 300. The oil doesnt really break down much if its not already at end of life. If it has 75000 hard miles already and then you town a boat up the grapevine pass 20 miles uphill at 70mph, the oil will probably turn black. However the screaming noise isnt actually from the oil breaking down, its cavitation from boiling of the oil causing air bubbles that are being compressed by the pump and making noise as they bounce the pump with air/oil alternating pressures during its rotation. Its bad because it signals the oil is boiling...which is hard to do unless its really hot (The whining/buzzing typically start at 240+, gets loudest at around 255-275 or 280 then the volume stops increasing).
I personally dont like anything CVT. Do I particularly hate the Nissan Jatco/Jeep CVT tranny? I dont think its a great unit even among other CVTs. I think it has some inherant design flaws (like its tendency to run hot above 2500 rpm, and the manufacturers tendency to not fix that problem and instead deny it till it breaks). But I can say the exact same statement about pretty much any CVT on the planet from any company. NONE OF THEM is good at dealing with heat, none of them are well supported by the factory or the aftermarket. Take your pick, Ford, Chevy, Honda, Toyota...doesnt really matter. They dont want them fixed or maintained. They want them to drive till they break(The magic numbers are 40k, and 100k), and then get replaced, or the whole car replaced. Hence the grotesque lack of internal component availability (Some valves and solenoids that should cost say 100 dollars each and the unit has 10 or 11, they require you to buy the entire valve body assembly and the module with it with all 11 installed...for say 2500 dollars shop cost, customer billed at 3300ish, to get
1 100 dollar solenoid! Rather than say change a single defective solenoid so the trans can go back into service for another 20 or 30k at least for under 500 to repair. Instead its 5000. Thats modern factory CVT logic). Think of the modern electronic sticks. For those not aware, many modern "autos" arent really autos, they are stick shifts with clutches that are depressed and shifts done by the ECM using switches and servos and solenoids to replace the pedal and stick. I dont like those either. Too clunky, tend to be EXTREMELY labor intensive to repair (they like to cram all that electronic shift junk into the same cases and trannys they had before so its really a mess spacewise)
By all means, I tell people do what you can with what you got. ALL manufacturers are using CVT or electroshift stick now. ALL. On paper, it saves gas and thusly makes less emissions. Because of that, it is the only future for combustion transmissions until electrics and fuel cells push them out in 10 or 15 more years. Its slightly depressing as a technician. I can name at least 10 or even 20 transmissions from the past 50 years from most of the worlds manufacturers that were capable and even likely to go 200k with little or no breakage if they got only occasional maintenance and werent abused.
NOW? I cant think of many Id expect to consistently make it to 150 unless extremely well maintained or primary low load operation (Fluid services BEFORE factory intervals, and no warm weather loaded operation ever).
Adding an external cooler is a modification that works. On a 1975 to 2000 vehicle, it could be argued it was a waste of time unless it was a tow vehicle. Those pre-computer trannys had massive drums and clutch plates, bigger bearings, took 12 quarts of durable fluid and they ran much cooler than the modern stuff. On a modern CVT? It helps. It makes a 30 degree difference that can be measured with a temp check or a graph on a scantool. 250 degrees after 20 minutes, dropped to 211 stable. Still not the icy 175f of a 1990 ford or chevy at 20 minutes, but its not boiling and eating itself at 211.it can keep on rolling.