So the other day I noticed that mt temp guage was all the way up. I had just started driving 3 minnutes ago.

When I did the SR5 swap the temp guage would start at 1/2 up but never make it all the way up.

I read alot of post on the subject and still have a few ????'s to make sure I have trouble shot this propperly so far.

First thing I did was try to make sure there were nor air pockets in the coolant line. I did this by parking facing up a slight grade, radiator cap off, heater on, truck on, wife in truck. I figured there would be air bubbles or something but after 8-10 mins nothing.

I noticed the engine sounded kinda loud and I checked the oil level, dang it's low, so I added 1 1/2 qrts, ran smoother. Okay that's done.

I pulled this wire thinking it was the temp sender and if this was the problem the guage would drop to the bottom. When I pulled it nothing happened. Is this the correct wire to pull?

Please let me know if I did everything right, or if I should check something else, I am all out of ideas.

 

i just did the sr5 swap myself and have the same problem. the temp guage shoots straight to the middle as soon as the engine fires up. i thought that the guage was faulty since the guage worked properly on the previous cluster. perhaps there is a difference between the sending units on the sr5 and delux models? it seems like i might have remembered the parts counter guy asking if my truck was a sr5 or delux when i bought a replacement temp sensor? i have been meaning to test the guage but have not gotten to it.

 

I would think that the temp guage would be the same as they have the same engine but I could be wrong. Another thing is why would my guage stay at the top even after I pulled this wire (assuming this is the correct one)?

Anyone have any ideas for toyaholic and I?

 

i bet that your gauge cluster is messed up, my '84 SR5 cluster temp gauge goes to normal when i turn on the key, the sensor is not hooked up, try tapping the plastic in front of the gauge i can get mine to go to the cold mark if i tap i hard enough, then it will return to normal randomly, these gauge clusters seem to have problems with the oil and coolant temp gauges

 

The wire for the temp gauge is in the middle of the termostat, lower plenum, go from the cold start injector down... At least on my 88 it is. It's a single wire, spade connector. It's can get loose.

I believe (theory, based on other toytoas) that the SR5 temp gauge is dampened. That is it: it's designed to show "normal" within a range of temperatures. Above and below normal range, it jumps fast.. It's not linear. One day I'll look into fixing it.

I don't know why your junk got hot - if it was oil related, you'd notice that you didn't have oil pressure - or at least were losing it during deceleration.
No oil is bad, as you can imagine...

 

dcg9381, thanks for the info but that was all greek to me. So I did not disconnect the propper wire in my picture?(inside the green box) I know where the thermostat is but what is/ where is the lower plenum?

 

Very common problem when swapping SR5 Gauges in. Mine did it for about a year and a half before I fixed it. I should start by saying I checked the resistances across the back of the cluster and they're WAY out of spec, but it still works pretty well. What finally worked for me was wiggling the wires AFTER I plugged the connectors into the back of the cluster... those factory plugs don't hold them very securely. I've been experimenting with adding zip ties around the wire bundles to hold things in place more securely. Seems to be working so far.

 

I should add:

The FSM way of checking the gauge is this. Look on the back of the cluster. Behind the temp gauge are three mounting screws that carry current to the gauge. From top to bottom, they are designated TU, E, and IG. Resistances should be as follows:

Between Terminals, resistance should be (approx):
IG-TU: 135 ohms
TU-E: 138 ohms
IG-E: 273 ohms


But I can tell you only one of those figures was anywhere near correct on mine, and it still works just fine. I know because half my cooling system was air when I finished putting the new head on and it started to overheat lol.

 

I know the turbo trucks are different, but on the 87-88 - for sure:
The "intake manifold" is split into two parts. An upper part and a lower part - these parts are called upper and lower plenums.

Upper plenum:



Lower plenum:





I don't think you're messing with the right temp sensor. The temp sensor in the front (that you disconnected) is for the ECU. It's seperate from the manifold one.

The one for the manifold is on the lower plentum. If you look at the photo below, it's the small hole, top most in the photo. If you can identify what these parts are, it's near when the plentum bolts to the head. Find the middle of the photo, go straight up to the small hole. That's where the instrument temp sensor is:

 

yes, sender(temp guage) in the middle of the lower intake manifold and the sensor(ecu) in the front of the lower intake manifold next to the cold start timing sensor. the sender could possibly be in a different location on the newer 22re. check out the 93 fsm link to find out for shure. http://personal.utulsa.edu/~nathan-buchanan/93fsm/

 

Got it, thanks! I'll do that when I get home today.

Just make sure it's this one

 

bingo.

 

alright I pilled this wire and the guage dies, I think I'm gonna just buy a new sender unit and see if that works out for me. After checking the current flowing through the guage and checking the wires.

 

I think I've got a temp gauge if you need it.

I'm curious if toyota has 2 different senders for the sr5 - non sr5...

Test the sending unit.. Wait until it's cold. Measure the resistance between the prong on it and the ground.

Warm the motor up for 2 mintues. Measure the resistance. There should be less than before.

Warm up for another 2 mintues, measure again.. Resistance should be less...

It's unusual for the sender to fail... It's possible, just unusual.

You could test the gauge by getting a pot (potentiometer) with a range of 500-40000 ohms.... Again, I think the gauge is dampened though...

 

cool thanks for the info