EDIT fj62 changed thermostat runs too hot now? Kickdown Adjusted

[MrMacdugal]

So I changed my thermostat out the other day. Changed both seals upper and lower for the upper housing. Also changed the temp sending unit. Changed for a few reasons but mostly as it has not been done since I owned it. Cleaned the parts and pretty positive I seated the upper o-ring well. When I yanked off the sending unit plug the inside of the sending unit came with it, so it was clearly very corroded and old. Glad I changed that.
But after refilling the coolant, making sure its not leaking anywhere and running it a few days to try to clear out any air in the lines, the temp it now runs at has changed. It used to run just below the half mark on the gauge, now it reads above half.
In order to be sure my rad cap is working the way it should, I ordered a new one. Should have it today.
I have ran it without the cap on at higher rpms, turned the heat on and off(which is working by the way) a bunch of times, left it parked overnight on a pretty steep grade, nose up. Not positive the air is gone as the top rad hose still feels soft when I squeeze it. Shouldnt it be pretty full and pressurized with coolant?
Anyways, pics below of the new temp it reads... I know, I should use a temp gun to see the temp at the radiator, which I will do today. Other than that, am I missing something, or is this the new temp it runs at? For what its worth, I did see it go up pretty close to the HOT line, but went back down. Its pretty chilly here right now, so i'm sure thats helping to keep it from getting too hot.

 

[Willard]

When you bleed the the system of air, a trick I use is to squeeze the top rad hose every so often to force the air out of the system.
I bet you still have air in there. I ran mine for almost an hour bleeding it the whole time before I was satisfied.

 

[Randy88FJ62]

Everything you mentioned sounds like you did it perfect. Maybe others will say they had a bear of a time burping the system? I assume you used pre-mixed or proper ratios of coolant. Can't think of anything you may have done wrong.

Maybe the temperature sending unit you bought is suspect? I checked the P/N and it's the correct one.

 

[Seth S]

Just because the temp gage isn't reading dead center doesn't mean its running too hot. Best to get a laster temp probe and check the top and bottom heater hoses and maybe different parts of engine and radiator. Or you could put the old thermostat back in and see where the gage reads.

 

[Willard]

Just because the temp gage isn't reading dead center doesn't mean its running too hot. Best to get a laster temp probe and check the top and bottom heater hoses and maybe different parts of engine and radiator. Or you could put the old thermostat back in and see where the gage reads.

Exactly,
And while you have it apart again, throw in a mechanical gauge and verify the stock gauge is reading correctly. The stock gauge is more of a range than an accurate reading.

 

[OSS]

The receipt shown doesn't say "Toyota" for the sender. It's gotta be a genuine Toyota sender if you want the needle to sit where it should.

 

[MrMacdugal]

Unfortunately the old thermostat was chucked. I work in a large limousine manufacturing shop and when I came in the next day someone had tossed it out on me, so thats no longer an option. I am using the prestone green all makes 50/50(i know not the red oem stuff) as that is what has been in there since the previous owner.
I have had the cap off and squeezed the upper hose and got bubbles to come out the cap while the truck was running a couple different times, but didnt seem to get it solved. I guess I need to do that more, but I was afraid I was actually pulling air back in when I let go of the hose. I dont know why I thought that because it shouldnt be possible if when i release the hose there is only fluid present at where the blockage is, it should suck fluid back in. Pushes air out pulls fluid in, kinda like squeezing the air out of a turkey baster while the tip is submerged in all that delicious turkey grease, youre gonna suck grease back in when you let the ball go.

 

[Randy88FJ62]

Green is what I have used forever. Prestone is fine.

 

[MrMacdugal]

I am willing to get the correct Temp sending unit, or replace this one as the box that it came in just said automobile switch on it with no numbers or anything. Can anyone give me a link or part number of one to get they know is the correct one? 1988 FJ62
Also, if the "plug"/connector was corroded and not making good contact could that be the problem? The TSU i removed was corroded and the connector yanked the innards out of the old tsu which means the conector was on that tang really good, meaning it was probably corroded. If I wanted to replace that connector, could I just clip it off and put a new generic spade connector on it? I have boxes of them at my shop, but obviously do not have this exact plug.

 

[OSS]

This is the Toyota water temperature gauge sender PN:
83420-20020


It looks like this:

 

[Randy88FJ62]

I use a generic spade on mine and my temp gauge works fine with the OEM sender. I reused my old sender and sand papered the male spade to get fresh material for the connection.

 

[Willard]

I am willing to get the correct Temp sending unit, or replace this one as the box that it came in just said automobile switch on it with no numbers or anything. Can anyone give me a link or part number of one to get they know is the correct one? 1988 FJ62
Also, if the "plug"/connector was corroded and not making good contact could that be the problem? The TSU i removed was corroded and the connector yanked the innards out of the old tsu which means the conector was on that tang really good, meaning it was probably corroded. If I wanted to replace that connector, could I just clip it off and put a new generic spade connector on it? I have boxes of them at my shop, but obviously do not have this exact plug.

Or you could just put a small file or emery cloth in the there and sand it, this should work as well.

 

[MrMacdugal]

Thanks. I'll probably clip off that end and put a generic spade connector on there to be sure I'm getting a correct reading.
Its rather strange you give me that part number of 83420-20020. Definitely not saying you are wrong, rather i would actually go with what you gave over what the Toyota dealer showed me for a part number today when I was there. They gave me 89422-30020 sup'c to 89422-12010
Especially whereas 83420-20020 is only $9.90 vs. $95.71 that the dealer quoted

 

[Randy88FJ62]

The temperature sender tells the gauge in your truck what temp it is. The thermo switch on the driver's side in the more expensive one. I found one on eBay for less than $10 and it's in the mail as a back up. We'll see what it looks like when it comes in.

 

[lovetoski]

As noted above, proper burping is essential. A couple of things that help:
Front tires up on ramps.
Funnel inserted into top of radiator. I use this one https://www.amazon.com/Lisle-24680-Spill-Free-Funnel/dp/B00A6AS6LY
Fill the funnel 1/2 way (mine fits tight into the radiator, it doesn't leak)
Start the engine, run at 1500 rpm to get the coolant really circulating.
Repeatedly squeeze the upper radiator hose to help force out bubbles.
Keep the funnel at 1/2 or more.
Do this for 5 mins or so.

 

[MrMacdugal]

Are you using any of those little attachments with the funnel or just the funnel alone? I assume no attachments that way the air has a way out around the funnel and then once it starts to suck back in its taking coolant with it. Sound about right?
Also put a new spade connector on the TSU. The old one was toast. Gage still at the same temp reading. Will try the funnel burping technique tonight.

 

[lovetoski]

I don't use the attachments - that funnel fits tight into the radiator opening. You fill it half-way (which means the coolant is above the top of the radiator). Then when you squeeze/pump the upper hose the bubbles get pushed out through the funnel. You'll see the bubbles come up in the coolant that is in the funnel.

 

[WILLD420]

If you are expecting a 30 year old gauge with an aftermarket sending unit to read the same as the old junk, you are expecting too much. Mine reads all over the place. I only pay attention when it goes up by the top and most of the time that's because of the voltage regulator thing since the gas gauge is making me get Prius mileage.

A heat gun is the only way. Bubbles are going to happen in there. If you are revving the motor up without the cap on, the pump will cavitate if you go too high and you will get air where there wasn't any.

 

[4Cruisers]

89422-12010 is the water temperature sensor for the EFI system, not the sender for the gauge.

 

[morganism]

Hope you put the 190 temp thermostat in, the 180 makes it run hotter in the 60s.

Burp, and park on an angle while running, not parked overnight. Once you sit for 10 min or so, turn on the rear heater too....

can back that temp sender out to bleed if the wire isn't connected.

I usually drill a emergency bleed hole thru the plate, in case the thermo fails out here in the desert. Did you put in spring up, or spring down?