I got another question for you experts.

My 1989 4runner SR5 automatic, won't stay in overdrive. It kicks in rarely, and when it does, it doesn't last very long. Gas mileage is absolutely terrible due to it not kicking in, giving me about 8 MPG at best.

This thing has been sitting a while, and I've added some Lucas Oil Transmission stuff into the tranny fluid, and hoped that will work. It has helped a bit, but still not enough. I've only been driving it for a week.

I was wondering if there is some kind of solenoid, fuse, or wire that could be blown or loose, because this gas mileage is killing me.

Please reply ASAP, thanks.

 

What size are the tires? Some 4Runners can't pull OD depending on gearing, tires, or motor condition.

 

From what I'm remembering, stock tire size.

235/75-15.

 

thermostat not stuck open?

 

The OD is temp controlled if I'm not mistaken... My OD won't kick on until warmed up. Maybe your thermostat is stuck open?

EDIT: Whoops... didn't see Vital's post

 

my truck has done this twice since my swap about 4k miles ago.

if i push the OD button off and on, on the shifter it works fine, like the OD switch contacts need to be cleaned.

like has been mentioned above it has to be warmed up before it shifts past 2nd.

nice lookin 1st gen.

 

Probably is, because we just had to replace the head gaskets and get the radiator flushed. I'll check on it right now.

UPDATE: That was the valve cover gasket, my bad. I am getting heat and AC so it shouldn't be the thermostat, should it?

 

Start here:

 

Yeah, I had to remove the button in the shifter and clean it too. Solved my prob many years ago.

 

The contacts on the overdrive button are under the white plastic cover, right? Wouldn't imagine they need cleaning since they are under that cover. Just making sure those are the ones I need to clean instead of others.

 

Nice find BMcEL. Id start with that before worrying about the button. If the button wasnt making contact you would see the o/d off light turning on. It wouldnt just cause it not to shift into OD without turning the light on aswell.

 

Been there, done that.

 

BMcEL, got a closer up view of that E17?

By the way, seems like it can't be the button, I can turn overdrive on and off.

 

I didn't read all the details, it's not your button. Carry on.

 

I don't. It's pretty easy to locate...just follow the wiring that runs across the top of the timing cover and you'll see the splice behind the power steering pump.

 

It is more likely the coolant temperature sensor than the thermostat (given that heat works). But rather than guess, just run thought the diagnostic: http://personal.utulsa.edu/~nathan-b.../6overdriv.pdf

 

Super late response, but it was the Thermostat. Thanks everyone.

 

Having very similar issues, won't kick into O/D when it does it doesn't last very long, maybe 10-15 miles, at 65. Dealership says everything is fine. I'm lost, and pissed.... 93 SR5 4x4 extra cab 3.0 V6 Auto.