overheating Archives - Transmission Digest
Sonnax highlights Thermal Bypass Eliminator Kits

Sonnax highlights its thermal bypass eliminator kits, which the company says can prevent transmission overheat in several popular Chrysler, Jatco/Nissan, ZF and Mercedes transmissions. These kits allow reuse of the OE cooler bypass valve by removing the OE thermal bypass valve and replacing it with either a plug or valve assembly that permanently allows flow

A 5R110W With Transmission Overheating

A laser gun was used to check the temperature of the oil pan sump, confirming an overheating condition did exist.

Toyota’s K313 Continuously Variable Transmission

In 2014, Toyota introduced the K313 Continuously Variable Transmission in their 1.8L Corollas vehicles. It utilizes a torque converter eliminating a forward or reverse clutch-release strategy when in gear at a complete stop. The torque converter neck is a double-ear drive design that indexes into the inner pump gear.

Beyond the Pressure Regulator: Keeping Cool While Investigating Mystery Honda Overheat

Most transmission technicians are aware of the notorious loss of proper converter feed that plagues various Honda transaxles. For those who are less familiar, converter charge oil is cut because there is not enough pump output to keep the pressure regulator valve in the regulating position, allowing the TCC to drag and eventually disintegrating the lining. Many technicians have already learned the importance of installing a modified pressure regulator valve during overhaul that ensures converter charge pressure is available at all times, regardless of pressure regulator valve position.

Reflashing Job Takes a Different Turn

He goes on to explain that it is a 2002 PT Cruiser, and it starts overheating whenever he runs the A/C and sits in traffic. He traced it down to the fan relay and replaced it with a new one. Apparently that solution didn’t work, so he was trying to bypass the relay to get it to turn on the fan, and smoke started coming out of the computer. So he got a used [computer] and put it in but it still wouldn’t start. He said D.J. said it needed to be flashed and that I could do that. He added, “I could bring it to you, as I already have it loaded on a trailer.”

More Torque-Converter Forensics

Try to imagine the difficult job tech-line technicians have. They are asked to decipher bits and pieces of information that may not be accurate and then come up with the correct answer. The information the technicians collected for the following two scenarios seemed to be as different as night and day. The information even originated in different countries. The amazing thing about these different complaints and symptoms was that they all had the same root cause.

Adventures in engine cooling

The coolant level in the overflow was “full”; however, the level in the radiator was a half gallon low. Even after I topped off the radiator, the engine overheated after running for only 10 minutes. The cooling fan worked, and the temperature of both radiator hoses indicated that the thermostat was wide open. I wondered if there was a circulation issue such as a water pump that decided to fail, or a radiator with internal blockage. The radiator and coolant both seemed clean, and I observed flow when I peered into the radiator neck.

Food for Thought: How Hot Is Hot?

How long have you been in the transmission business? Have you ever honestly sat down and thought about how an automatic transmission heats up? I mean, how hot does it get and how fast does it get there? Does the temperature stabilize as it does in an engine, or is it always changing? Have you ever taken a car for a nice long drive to be sure you “got it hot” and not been able to reproduce the problem? I’m sure you always figured that stop-and-go city driving creates more heat than driving on the highway, but how much more?

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