2TRFE over heating got me stumped

Truck is a 2008 4x4 5 speed 2TRFE. At 150k I replaced the thermostat from the Toyota dealer, replaced water pump with Aisin part, replaced fan clutch with Denso part, replaced coolant with Toyota Long Life. I didn't have a reason to replace that stuff, just preventative maintenance. It has gotten progressively worse since then. Truck now has 197k, has been running hot ever since. Ive had a Scan Gauge since new, never went over 193 degrees. I again replaced the thermostat with a new dealer one, no change, flushed coolant/bled 4 or 5 times, no change. Did a pressure test, all good. Replaced radiator with Denso part, a little better, but still getting over 200 degrees on the Scan Gauge. Truck temp gauge on the cluster doesn't indicate over heat, but I can tell the engine is running too hot, fan comes on as well, which it never did before. When I put the AC on it helps keep it under 204 degrees, its been up to 216 degrees. I'm stumped, its never run this hot since it was new, am I missing something? Everything's been replaced that I could think of

 

Sensor?

Hoses?

 

Air bleed out?

 

Maybe the thermostat you got was rated for a slightly higher temp then the original one. Like an updated part. 200 degrees doesn't sound terrible but I know what you mean about how it never ran that hot before..

Are you sure you don't have an air pocket? Put a spill funnel on the rad with some coolant in it and pull one of the little throttle body hoses off and see if any air comes out. If it's a steady stream you're good. pull one the heater hoses off at the back.

 

Subbed for outcome

 

Somebody else suggested a sensor, but I thought the check engine light would come on in that case. I bled the system for like 3 days and hours on end, but that's the only thing I can think of.

 

The check engine light only relates to problems with the emissions equipment. Turn on the heater for 10 or 15 minutes while the truck is running but after the engine is already warmed up. There might still be air trapped in the heater core.

 

When you say bleed it, do you mean run the engine with the radiator cap off and look for bubble burps? Or did you pull a heater hose or something near the back of the engine?

 

Make sure the new thermostat isn’t defective. Pop it in a pot of boiling water. I’ve had this happen on a chevy traverse. If everything is checking out, make sure you bleed it good.
Couple tricks include using a spill proof funnel to put coolant in. Helps with releasing air bubbles while adding coolant. Jack the front end of the truck up a little bit so the radiator cap is the highest point. Make sure you turn the heater on. Sometimes to push air bubbles out of the heater core you can rev it a few times. Get a temp gun to compare upper and lower hose temps. Don’t know what kind of water pump you got but ones with plastic impellers are known to fail. Make sure you don’t have any air flow restrictions through the radiator.

 

A few ideas.... Are the radiator hoses new? I have seen lower radiator hoses collapsing from age and oil softening, restricting flow. Have you added lights or anything in front of the grill? Are you sure you used the correct fan clutch when you replaced it? Some will fit but have different characteristics. Are all stock fan shrouds in place? Does it heat up at idle or at highway speeds?

 

But did you replace the radiator cap!

 

Did you install the thermostat in the proper orientation? There is a jiggle valve on the thermostat. It has to be at 12 o'clock (+/- 10 degrees). Having the jiggle valve in the wrong orientation will make the engine run hotter.

https://www.customtacos.com/tech.ol...6toyrm/06toypdf/06rmsrc/rm2006ta/01700410.pdf

 

He mentioned that he installed an Aisin pump. Aisin makes the OEM pumps that are on the 2TR. It doesn't have a plastic impeller.

 

My fault for skimming

 

I will give you a few items out of my Haynes manual that will be a long shot but hasn't been mentioned on this thread yet. 1.) Drivebelt defective or not adjusted properly. 2.) An improper grade of engine oil. 3.) Insufficient coolant in the system. 4.) Inaccurate Scan Gauge.

 

This. Happened to one of my earlier 4cyl. Lower hose was collapsing.

 

if the problems started when you began replacing parts (water pump, stat, etc) them my money is on an air pocket

 

A year or two back someone here made a thread about over heating, and they realized that their radiator was clogged with mud/dirt from offroading.

Could be simple..

 

Indicative of a faulty radiator cap

 

Bad bottom hose or a bad ring on a piston?