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Ted Ritter
Ted Ritter, Toyota Master Tech
Category: Toyota
Satisfied Customers: 4182
Experience:  Toyota Master Tech, ASE Certified
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My A/T oil temp comes on when driving what cause that, V6

Customer Question

My A/T oil temp comes on when driving what cause that
JA: What size is your engine? How many miles since your last oil change?
Customer: V6 Toyota hilux
JA: What year is your V60?
Customer: 1991 just service the gear box 4 days ago
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: It only comes on when engine is not
JA: Anything else you think the mechanic should know?
Customer: Hot*sorry
JA: Huh?
Customer: Still there
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Toyota Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Toyota
Expert:  Ted Ritter replied 5 months ago.

Hello, thanks for posting

How long have you owned this truck, how many miles are on it?

Was the transmission fluid changed recently?

Expert:  Ted Ritter replied 5 months ago.

let me go ahead and briefly explain why this is happening, this used to be a bit of a common problem a few years ago when more of this vintage trucks and 4 runners were around, I owned a 90 4 runner for a few years and had this some problem.

As the fluid heats up while driving it may get to the point where it starts to foam up, this foam and air above the fluid gets much hotter than the actual fluid, the temperature sensor is located a little above the fluid level and senses to temperature of this hot foam and the light comes on. We found that using a different type of ATF solved the problem permanently, I think it was Nissan atf which had different anti foaming agents, not sure if it's even still available but there are other fluids you can try using, most fluids a better these days anyway.

I would recommend using Valvoline Max-Life which is a multipurpose fluid that is compatible with even todays WS type fluids and can be used as a replacement. I would highly recommend removing all the old fluid using a trans flush device, the add a can of Lucas transmission treatment, hope this works for you, unless there is a problem with slipping of clutches or internal pressure loss this should work.

Also make sure the transmission oil cooler is intact and has not been removed by a previous owner and if necessary you could also add an aftermarket cooler, the idea is to keep the fluid temperature down to keep the fluid from foaming up.