Is thermostat hard to replace?

[alp]

Relax. 50/50 Coolant/Water mix boils at 225°F. But put a pressure cap on the system and that goes up to about 260°F. That said, I don't believe 4Runners usually run hot. My temp gauge stays slightly under half in normal driving. The only time it got above two-thirds was a 90°F day in traffic with a bum fan clutch. Swapping the clutch fixed that. If your problem is in traffic and not at speed, check your fan clutch.

I do monitor the coolant temperature with the Scangauge and at highway speeds it shows 207 deg.F most of the time. Sometimes it's even going up to 212 and then down to 195. Then back to 207 and stays there. What I red on this Forum most people normally see the coolant temperature around 190. That makes me nervous and I am planning to replace my still original radiator with the Koyo one and put the new thermostat.
I wonder what would be the p/n for both thermostats - 170 and 180 deg.F?
Thanks

 

[Mr. Leary]

Which thermostat did you put in the 170 or 180 degree? My gauge reads that I am getting up to 208 degrees and I think it's too hot(this is with the lever turned all the way to the hot position) I sometimes blast the heater to get it back to 203 degrees. I can only imagine what it will read when I have to use the air conditioning. I thought anything over 212 degrees is dangerous since that is the temp water boils. I picked up a new thermostat from Toyota - I guess that it's a 180 degree stat?

My truck never gets above 211, although it gets up to 209 all the time. Newish radiator, new water pump... truck just runs hot. My Land Cruiser gets that hot as well.

Relax. 50/50 Coolant/Water mix boils at 225°F. But put a pressure cap on the system and that goes up to about 260°F. That said, I don't believe 4Runners usually run hot. My temp gauge stays slightly under half in normal driving. The only time it got above two-thirds was a 90°F day in traffic with a bum fan clutch. Swapping the clutch fixed that. If your problem is in traffic and not at speed, check your fan clutch.

Analog guages are not effective for accurate temperature monitoring. They have much too wide of an operating window. A scan guage or similar is the only effective means of getting accurate water temp readings. Also, if your needle guage is showing that you are running too hot, its usually too late... you are already overheating and need to pull over, open the hood, and run the heater full blast.

Checking fan clutch is a good idea as it is often overlooked.

 

[MAD 69]

I use an Ultra Gauge to monitor my coolant temp as well. I'm pretty sure the OEM thermostat is the 180 degree type (ill call the Stealership today to confirm)

If my Rad blows up I'm coming over to your house Durk and borrowing your Runner!

Im wondering if Toyota sells the pre Mix 50/50 coolant blend or do they only sell the concentrated 100 proof Red Stuff. I'm thinking since my coolant looks filthy a flush and fill with the new radiator and thermostat should bring my coolant temps down below 200 degrees F. Since I have an AT should I just check to see if the fan is working correctly?

 

[Mr. Leary]

I use an Ultra Gauge to monitor my coolant temp as well. I'm pretty sure the OEM thermostat is the 180 degree type (ill call the Stealership today to confirm)

If my Rad blows up I'm coming over to your house Durk and borrowing your Runner!

Im wondering if Toyota sells the pre Mix 50/50 coolant blend or do they only sell the concentrated 100 proof Red Stuff. I'm thinking since my coolant looks filthy a flush and fill with the new radiator and thermostat should bring my coolant temps down below 200 degrees F. Since I have an AT should I just check to see if the fan is working correctly?

Check the fan.

I would stick with Toyota coolant as well, not need for 50/50. Toyota red is a coolant with low glycerin content, which is easier on the internals of the engine as far as rust goes. When we had to do an emergency flush on my land cruiser in Big Bend, my fluid was very rusty. If I had Toyota red in there the coolant would have been in much better shape. The flush will probably get you running about 3-5 degrees cooler.

 

[TheDurk]

I use an Ultra Gauge to monitor my coolant temp as well. I'm pretty sure the OEM thermostat is the 180 degree type (ill call the Stealership today to confirm)

If my Rad blows up I'm coming over to your house Durk and borrowing your Runner!

Im wondering if Toyota sells the pre Mix 50/50 coolant blend or do they only sell the concentrated 100 proof Red Stuff. I'm thinking since my coolant looks filthy a flush and fill with the new radiator and thermostat should bring my coolant temps down below 200 degrees F. Since I have an AT should I just check to see if the fan is working correctly?

HEY! I was just saying it won't boil at 212°F--I agree you should take care of your cooling system. I would definitely make sure I had clean coolant and a solid fan clutch before I tried to Band-Aid it with a lower temp thermostat. And, at least in my case, the analog gauge gave me enough warning to abort my trip through the Lincoln Tunnel before I was in it, stop and cool down, then return home at speed to diagnose the problem and avoid serious overheating. I knew I had a problem when I got to two-thirds, never got to red.

Just out of curiosity, where does your analog gauge sit?

The best indicator of a working fan clutch is that familiar roar on start-up that goes away after a few seconds. The best indicator of a bad one is a heating issue only in traffic. Then, when vehicle is running too hot, see if you can stop the fan with a rolled up magazine or newspaper. If you can, time for a new clutch. You can get the OE Aisin clutch at partsgeek.com or elsewhere for far less than the dealer price and have the exact same component less a red box. We had a number of these clutches go last summer, so I expect we will this year, too.

As of last summer, my Toyota dealer parts guy only had Red and had never heard of the pink. He swore the Red was the only one Toyota made. He ain't too swift--but we know each other going back to my 1980 Corolla. So the only way to know is go to yours and ask, since it obviously depends on the individual dealer.

 

[MAD 69]

The Durk wrote:
Just out of curiosity, where does your analog gauge sit?

My says I'm at halfway, my Ultra Gauge reads anywhere from 203-208 degrees.
My grandmother won a 1980 Corolla at our local church carnival - we put about 400K miles before we sold it.

 

[cj80cruiser]

Im wondering if Toyota sells the pre Mix 50/50 coolant blend or do they only sell the concentrated 100 proof Red Stuff.

I saw a gallon jug at the toyota dealership near me that said 50/50 on the outside. I'm assuming it was a 50/50 mix of red.

 

[TheDurk]

I saw a gallon jug at the toyota dealership near me that said 50/50 on the outside. I'm assuming it was a 50/50 mix of red.

The Super Long Life (pink) says 50/50 Pre-diluted--was this it? The pink is NOT a 50/50 mix of red, they are different technologies.

 

[MAD 69]

So we have to buy 3 gallons of the pink, I was originally going to buy 2 gallons of the Red and 4 quarts of distilled water. Now I can avoid buying the distilled. I called 1 dealer and said he only carried 100 proof Red. I have to call a few more Toy dealers.

 

[SmellaRat]

The Durk has it.. Just bought my 2000 4runner... Can you push the fan clutch when shut off? is their any Free play or very tight.?? Read some posts on the fan clutch going out... I started there... with one more tip... find someone at work that will let you spin their fan blades... does yours spin as freely???? mine did not. I replaced the fan clutch and since then with Blue Tooth ODBI2 connection the coolant level runs 196 to 208 depending on the stop and go traffic..

Thought this may help.