93 4Runner/V6 will not go into O/D

[Brian R.]

Faulty fan clutch is way down on the list. A bad clutch would make the whole radiator hot, not just the top. The problem appears to be poor coolant circulation, not poor airflow through the radiator.

[gdlathey]

We'll try the flush first, then see about the water pump. Should we just run a hose in through the top radiator hose and see what comes out by the thermostat? Not sure on this...I'd hate to push the blockage any further into the block. Is the water pump an easy replace?

[4Wheel]

Hey it worked until you fixed it right? Just a shifting problem. Concentrate on what work was done that made it worse!!
Again if you still have the old thermostat, put it back in to try to get it back to just a shifting problem.

Even a BAD stat will open in boiling water.

The new thermostat is bad or it is installed backwards either of these scenarios will produce your symptoms. The more probable is that it is installed incorectly.
You're not listening and it's costing you money.
We are trying to help you, please listen.

[Brian R.]

^^Test the opening temperature of the new thermostat more carefully and make sure it is installed correctly with the jiggle valve up and the coil sensor inside the block.

[gdlathey]

The stat is installed properly. Just as in the picture on page 1. Jiggle valve is at the 12:00 position. It says 82 degress Celsius on the stat. I will pull it and test the water prior to testing it again. Haven't had time to work on it yet today. I'm thinking it has to be either blockage somewhere or the water pump is not working. I really do appreciate the help. More to come....

[4Wheel]

What side is the spring and sensor on?
I HAS TO BE towards the block!
Lets take a look at what has happened, it worked well other than a OD shifting prob. Then the thermostat was replaced and everything went to hell in a hand basket.
So “SOMETHING” happened in the R&R process. If you are damn certain that it is installed correctly then there is another problem that just surfaced after the R&R of the stat.
Inspect the hoses.
Do you have the old thermostat? Put it back in, in other words bake out all the changes made that made this happen.
If you don’t have the old stat just eliminate it for testing purposes, it will tell you if you still have a blockage.
I am sticking to the stat being in backwards or that hose is compromised.

[gdlathey]

Old stat back in and back to square one. Not shifting into OD. Different "new" stat and overheating. The stat is in the correct way. Coil spring towards block (just as in picture on 1st page). Where is the ECT sensor located on the block? Will I get anywhere if I put the hose in the top hose and see what or how good the flow is out of the block where the stat is located? Might be some blockage in the block somewhere.

[Brian R.]

ECT sensor is on top rear of engine.

[4Wheel]

Wait! If you put the old stat back in and the overheating prob goes away look CLOSELY at both stats and find the diference, What is the temp stamp on both? A blockage in the block will cause overheating with BOTH stats.

[gdlathey]

I'm kind of thinking it may be blockage in the block. How would one clear that out?

[4RUNNER_RIDER]

Originally Posted by gdlathey

I'm kind of thinking it may be blockage in the block. How would one clear that out?

there is a second drain plug that is locate some where around your oil filter if you found it drain it and use a water pressure hose and stick it in there then flush the hell out of it, or you can leave the second plug open and use the hose on top outlet and flush it from there, if you want you can run the engine at idle, did you change the water pump yet? about your fan clutch did it run very fast at first start? then will slow when the engine is warm? and while driving does the fan run as you press the gas? so are you saying it get hot while driving? so like they said blockage... I never got this problem on any of my car... only for my celica that it will get over heat when you idle it to long but as you go it will cool down, if your is not like that then it should be your water pump or blockage or is your head gasket in good condition? no white smoke coming out from the muffler?

[gdlathey]

The fan does go fast at initial start up, then slows down as engine warms. As far as the white smoke, this is Minnesota, nothing but white smoke coming out of every car here after October 1st...lol...It's hard to tell. The oil looks clean, not milky at all. I had an old 1980 Hilux and blew a head gasket on that, so I'm kind of familiar with that whole deal. I think the head gasket is in good shape..I'll try to flush it out after Christmas and see what happens. It's been warm here the last day or so, and the stat that is in there now, has 4 small holes drilled in it. It seems the warmer it is outside, the better the thing runs. Started it up today and let it warm up for 20 mins or so (it's 35 degrees here today) and it had no problems shifting into OD today. I can't find the ECT sensor....there are 5 sensors at the back of the engine by the firewall. Chiltons book doesn't tell you squat. Anyone have a good schematic of which one it is?

[corbinwaterski]

http://personal.utulsa.edu/~nathan-b...98engineco.pdf

OR

http://personal.utulsa.edu/~nathan-b...82operatio.pdf

[gdlathey]

[QUOTEBlown head gasket, Sorry.
On these V6s there won’t be much of any other symptoms no oil in the water check your compressions look closely at the #1 and #6 cylinders.
Head design causes excessive wear (from expansion/contraction against alu/iron) on these two cylinders.
Do a search in this forum for head gasket and read on. Many posts here about the problem with Toyota’s V6 head gasket. The service campaign has long since stopped.
when you had the timing cover off you might have noticed seepage at the #1 cylinder head/block interface.QUOTE]
4Wheel,
You posted this response on another post about overheating in the V6, do you think I may have the same problem?