88 toyota pickup 22re question

what is the thermoswitch that controls the automatic transmission overdrive supposed to look like and where is it located?

i found the part number online - 89428-20050, and ordered one, but the one that arrived is different to what i think is the thermoswitch on the motor. mine has a round connector, the one that i was sent has a square.

the reason i suspect it's the wrong one is that the part package, while correctly labeled, had been opened, and the part inside has obviously been handled a lot - i think someone substituted the wrong part into the right package, and it's been going backwards and forwards in toyotas parts returns system ever since.

anyway, i want to be sure whether i'm looking at the right component. it's screwed into the block slightly above and rearwards of the oil filter. correct?

Reply to
jim beam
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ok!!! guess i need to get the thing up on the lift 'cos i sure can't see anything else from on top.

ok, definitely need to go in from under. i don't recall anything there from when i did the head, but i'll check again.

apart from the intermittent overdrive, it's running like a top. the low idle has gone away now i've done the head gasket, i'm getting some oil leakage from the rear seal, so i'll use some "high mileage" oil in it on the next change to dose it with seal conditioners and put off the evil hour when i have to take the motor out to change it.

the head gasket was a goat f*ck of a job. two of the head bolts had been subject to coolant leak over a protracted period, and since the cheap-ass who'd owned it before wouldn't pay for "anti-freeze" with corrosion inhibitors, they were rusted to less than half their original width! not only did that make them hard to get out, it had also "exploded" the head. since rust takes up more volume than metal, the increased size of the bolt/rust mix had started to mushroom the head hole. it was this that blew the gasket - it was pressing the head up from the deck! ended up chiseling the two mushroomed regions off [since i didn't want to get the head skimmed], using a starrett straight edge for reference, and used a m.l.s. gasket on re-fit. it's been fine so far. we'll see how long that lasts...

last thing is the transmission output is a little sloppy. not sure if it's the prop shaft socket or the transmission output pinion since i've not dissected, but it's silent, and not leaking much oil, so i'll leave it for the time being.

Reply to
jim beam

Hmmm...it's been a while since I hadd a 22R but I think that's the knock sensor!

On my Supra, the sensor for the AT Temp is in a housing on the front of the engine, below the guage sensor and the t-stat. Don't know if it's the same on the 22R. Ask in toyota, and maybe Ray will answer. He knows this engine fairly well.

How's the truck running?

Reply to
Hachiroku

Not bad. It is an old truck, and I'm still jealous (they were nice trucks...except for the rust problem up here...)

If you can get a hold of the repair manual, you can "trick" the OD by putting a switch across the leads going into the computer. Note, however, if it's a lockup torque converter type, it won't UNLOCK when you need to coast! That means you need to keep your foot on the gas!

But, if you're like me, you do anyway! ;)

Reply to
Hachiroku

i found an online toyota manual, but it's a scan of the paper version and thus not searchable. i've looked through most of the 1000+ pages, and the circuit diagram for the overdrive doesn't show the thermoswitch!!! thanks toyota. i found reference to it in the main schematic, and in various blog posts, and using that info, i tracked down the part number, but still nothing showing the location of this thermoswitch. i've i.d'd the coolant temp sensors for the ecu and the gauge, and the cold start injector timer, and thanks to you, the knock sensor, but nothing else that vaguely looks like the part i've been sent. really don't want to have to take the manifold off to see in there again.

Reply to
jim beam

is this what i'm looking for?

can't see how it would unscrew though. and it looks like it's something to do with the idle circuit.

so far, identified are

  1. coolant temp sensor - gauge
  2. coolant temp sensor - ecu
  3. coolant temp switch - cold start timer
  4. oil pressure switch
  5. knock sensor

there's nothing on my motor that looks like the thing i've been sent.

Reply to
jim beam

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