totallyunimodular

I have an 86 4Runner (22RE) that has a CEL about the water (coolant) temp sensor (code 4). So, I spent the weekend doing some much needed TLC in the hopes of addressing the problem. I cleaned the throttle body and cold start injector and installed new plugs. I still want to clean the EGR pipe and install a new water temp sensor. The old plugs were fairly white in color so it does seem that the engine was burning too hot and maybe the CEL code is spot on. Two quick questions to help a noob:

1) I have already soaked the 12mm bolts for the EGR pipe at the intake manifold end and loosened them, but I still need to loosen the nut at the other end where the pipe goes into the EGR valve. This nut is huge, maybe 27mm, and I could not get anything on it. Do I need some kind of special flare wrench to loosen this bolt? With the hood right above me, I need a short handled wrench with a huge opening and narrow profile...

2) There is relatively new, and expensive, Toyota Red coolant in their now. The FSM says to drain the coolant when replacing the water temp sensor. Can anyone say if this is truly necessary? I am hoping that I can use a small catch pan to catch coolant that leaks when swapping out the temp sensors, and then just top things off as necessary. Also, the FSM says to apply "sealant" to the sensor threads but I am not sure what, maybe some type of RVT?

Thanks for any and all advice!

totallyunimodular

OK, I got the EGR flare nut off by just getting it to break open with an adjustable wrench. I then had to use a vice grip wrench to spin it loose. I still might try and find a 27mm combo wrench to make sure I get it back on sufficiently tight, but at least I can start cleaning the EGR pipe.

I am still looking for advice about the coolant temp sensor though. Has anyone tried to change the sensor without draining all of the coolant? Not that big of a deal but since its almost new coolant I'd like to avoid that step if I can.

Thanks!

raydouble

Don't know how far it's going to shoot....lol.
Definitely better than draining and refilling.....I'd try it, be quick. You can use a low strength thread locker as a thread sealant, but I don't know which one toyota recommends specifically.

4Reigner

i just changed my coolant temp sensor, it's too easy.

Pop the cap on the radiator to release pressure, then put it bak on to avoid coolant loss.
Place a bucket under the car to catch waht little coolant you will loose.
Unplug the wire to the sensor.
Loosen the sensor with a 19mm spanner.
Unscrew the sensor.
Install the new sensor.
Tighten with same spanner.
Replug the wire!

Took all of two minutes, and i lost maybe a mouthfull of coolant.

raydouble

lol....mouthful

totallyunimodular

Thanks, this is what I was looking to hear. I'll report back tonight to confirm if all went smooth...

totallyunimodular

Well, just like you guys said, changing the water/coolant temp sensor was pretty easy. I ended up removing the air intake tube (that connects the air filter box to the intake manifold) and disconnected a few quick-connect sensors to make room for wrenching. But, like 4Reigner said, a "mouthful" of coolant came out which was easily soaked up by a heavy duty paper towel. No need to drain all of your coolant! I should note that I was parked on an incline so the front of the truck was a bit higher than the rear, but I doubt that made much of a difference. Running strong now and I'll keep my fingers crossed the CEL does not come back on.