You guys are supposed to be the best forum out there. Certainly you have the coolest name.

So: 1999 T 4Runner Sr5/4wd
Was on a trip and had been driving for 40 miles at 65 mph on cruise when the A/T temp light started flashing. When I'd take my foot off the gas it would stop IMMEDIATELY.

So, therefore, it was always happening on cruise.

So I looked it up and noticed other people had similar problems at same speed/distance. The yesterday when I started it, let it warm to operating temp it started flickering again. There is no pattern. This isn't a blink it's the briefest of flickers. Then it will go dark, and flicker again. It seemed almost to match up with small bumps on the road (I live in deep country), and thought it might be a loose wirre. But if it were a loose wire, whether I had down on the gas or not would not matter.

The car runs in perfect margins everywhere else. SInce I bought it a year ago, although the vehicle has 230,000 miles on it, thos one-family-owned 4runner shifts and drives smooth as ˟˟˟˟ from a duck's ass. The tranny has been a little noisy since I bought it. A problem I remedied when I took the center cabin/plastic housing off the shifter and found that the boot there was torn. Contacting the guy who'd sold it to me he told me the tranny had been replaced in 2002 (it's a 99) and it had always been (very) hot around the shifter. You could warm a cup of coffee it had been so hot. So I insulated it. To no real immediate effect, except reduced cabin noise and temperature (what I'd wanted). I am SURE, at the very least the fluid has not been changed in 50,000+. The last owner, who had inherited from sister seemed to take her for granted. The fluid is a "normal" red and the level is perfect.

So there I am with a perfectly running vehicle with a blinking/flickering a/t temp light with no other symptoms except it stops when I take my foot off the gas. Again, it began on a longish trip. Yesterday it started out of the driveway. No way it could be overheated that quickly. RIght?

I fear the worst.

*The vehicle has some rust. A few weeks back I had a coolant leak. It was from the rear heater return. I by-passed to no immediate effect. Save for stooping coolant drip. Which had been my goal. I searched five states for a good Sr5. This vehicle means a lot to me. As a side note, I saw a LOT of them over 175,000 miles. Great vehicles as a whole!

 

I just have to ask, are you checking the trans fluid at operating temperature (while running) or cold?

 

Time for an external cooler and a scangauge2 or similar........
You need to know the real temps of that tranny.....so get a monitor or your tranny will not be good in a little while.

 

Zuk. Ok. 'll look into pricing. Hopefully it's something I can do myself. Before I do any of that would it be your advice that I flush and change filter?

Ksti. I have not checked it while running. No monitor at this point, and this being the firs time I have had a transmission "issue" I would not know what's normal. 300 degrees? The thing I am more interested is the flickering of the ta/t light. Most threads I read say that it is either ON or OFF, steady. Maybe not all the time, but when it does trip. Blinking usually gets "Oh that's electrical, a loose wire!" or "You are DOOMED. Flickering is the worst! Your tranny is already dead!" I don't think it's a loose wire because it wouldn't matter/stop when I take my foot off the gas/disengage the tranny.

 

Yes I'm scratching my head.
Monitor?
It's a pretty simple procedure, warm up motor, drive it a few miles to operating temperature.
Park it and pull the trans dip stick and see where level is at hot mark.

 

I would drain and refill the ATF (about 4 quarts) and drive it for 50 miles then drain and refill it again. The tranny contains about 16 quarts but you can't drain it all without doing a complete flush and not all flushing machines meet the Toyota recommendations for the 4Runner so it's better to do a drain and refill 2x or 3x. Then install an auxiliary ATF cooler inline with the stock cooler. Alternatively, you can bypass the stock atf cooler and install two large atf coolers.

Another thing is to flush the cooling system and replace with Toyota pink coolant.

I think the recommended maximum sustained temp for ATF is 200degF to make your tranny last long.

 

I have to wonder if another circuit is not grounding back through that circuit.

All the other work also can`t but help things

Since I never learned to drive those Automatic Transmissions I never bought one and never rebuilt one