Coolant running over 210+ F in Phoenix

[awesomeissquid]

If the bumper is causing airflow anomalies, it may be possible to add small vanes to redirect it similar to what is done on A320 engines. Of course you would need a CFD analysis done to identify the issue which would not be cheap nor easy. If all other solutions don’t pan out maybe removing the bumper and doing a test drive to see how it performs would be in order. At least that would rule out the bumper or identify it as the main issue.

 

[AFei]

This is how the bumper and winch looks like, and it does put a solid block to the air path of the bottom half of the radiator.

For now, I will try to replace the ECT sensor and adding some kinds of air deflector to the bottom of the radiator to guide more air into it. Also buying a kit to test the exhaust.

Removing bumper and winch might be the last thing to try

 

[awesomeissquid]

If you look at an OEM bumper it typically has a pretty solid piece where aftermarket bumpers are. The lights and winch box though are directly in front of the grille opening and probably causing the most impact.

 

[89BIGBLUE]

You could consider drilling some “breather” holes in the bumper…

The winch itself is a giant heat sink, so when it’s hot, it’s Hot down there!

I installed a hidden winch mount and winch behind the stock bumper on my 99, and have noticed a slight increase in average temps this summer in NM.
I might look at some creative “air dams” or “vent holes” this fall.

 

[AFei]

The lights and winch box though are directly in front of the grille opening and probably causing the most impact.

Yeah, thinking of removing the lights as it's the easiest one to remove.

 

[AFei]

You could consider drilling some “breather” holes in the bumper…

I believe the bumper has enough openings and think the winch has more impact as it is a big chunk sitting right in front of the condenser and radiator

 

[Mike NXP]

For what it's worth. I have a similar bumper setup with lights and badlands winch + I run a mesh screen year round and have no issues. BUT my area doesn't see temps over 100f too often so perhaps I'm not much of an example to compare with ..... I did a few days in Nevada recently in 95+ degrees with this setup and my temps stayed under 195 even when climbing hard in 4 low off road, usually right around 187...

Air flow is of course a good thing but I'm not convinced removing all of the stuff up there will fix the problem but suppose it's worth a try to help troubleshoot

I can't seem to find a pic with the winch installed but you get the idea , the badlands control box sits right in the middle there.

 

[2001LC]

Burping air from system is key. Check under rad cap, before sun-up when coolest OAT of the day, after 8 hour engine cool down, while parked with front end higher than rear.

Properly installed: thermostat (OEM, w/ jiggle value at top), rad cap, and proper working reservoir hose and its cap are all a must.

All 3 radiator fins, need washing. Air passing through fins, is key to dissipation of heat. But typically, we'll notice ECT higher when moving slower or stopped. If fins clogged.

Keep in mind. The first rad is the A/T oil cooler. If A/T fluid (ATF) running hot, we transfer extra heat to condenser and then engine rad.

We are seeing some weak Aisin fan clutches. Some refill with thicker oil. Toyota Aisin FC, are build to higher standard. As such, less issue out if the box.

The 06-07 use a different fan and fan clutch (thicker clutch, w/black mount flange). You mention major engine work. Make sure the FC and fan, was not switched to older style (FC has blue mounting flange).

If we know all of coolant system, service properly (most I see are not). AT Fluid in proper range. Then we need to look deeper.
Good starting place, is watching fuel trims and AT temp.

What are ECT, fuel trims and AT fluid temps readings. While on HWY, off road??? If running lean, cylinder head temp goes up.
At higher RPM, fuel pump runs in high speed. It may be worth monitoring fuel pump speed, if you find fuel trims running lean at higher RPMs, as ECT temp hit your highs.

If coolant system serviced correctly and all as should be. Then we must consider work done! Blockage is what comes to mind. Not just in heads, but block must also be considered. We just had one in mud. Where a shop towel left in a port during service, was causing blockage. Blockage can just be slowing flow or total blockage stopping flow, in one or more passages. These can be very tricky to diagnose.

???? Why were the heads R&R? Replaced with used or new heads? Used restored, and possible boiled?

One of diagnoses best clues or starting points, is: Did issue begin, after a service.

 

[toy_tek]

I think the 100 series cap is 16psi, so w a 50% mix, even at 210* you shouldn't be in any danger of boiling over.

Consider thicker weight oil in your fan clutch (as previously mentioned). 15 or 20 CST. The new Aisin clutch I got came with about 5 CST. It's cheap and easy to change and makes a huge difference when the water temp gets up there.

 

[Mike NXP]

View attachment 3720322

I think the 100 series cap is 16psi, so w a 50% mix, even at 210* you shouldn't be in any danger of boiling over.

Consider thicker weight oil in your fan clutch (as previously mentioned). 15 or 20 CST. The new Aisin clutch I got came with about 5 CST. It's cheap and easy to change and makes a huge difference when the water temp gets up there.

Can you post some more info on the clutch oil . How would one know what they are running and if it should be improved.

I guess only worry about it if you're running a little hot I suppose?

 

[aztoyman]

I think azusa nailed it a few posts back. I'm also in the desert heat in Tucson. Not a 100 but my truck did the same thing yours does after I added a bumper and winch. ONLY above 65 MPH. NEVER got hot under those speeds. I modified the bumper and problem went away. Sounds like you covered everything else.

 

[VentricularFib]

I'm in the same boat. Read all the Summer/normal Coolant Temps thread like 5 times. Threw a bunch of money at it with all new oem everything except Csf radiator
and still run hot. 191-195 here in (normal)Los Angeles weather. This was today after a trail airing back up near Yucaipa where temps were 115.I was in 4High towards the end so that's why my trans temp was so high. It ran 150-160s in 4L. I'm putting in a new Oem radiator in a few weeks from that sale from Decatur Toyota. I also think I may have narrowed it down to my homemade mesh style radiator that looks like it's restricting airflow, so ordered an eBay oem style grill too.

 

[J1000]

More water, less antifreeze will cool better, especially if you don't have to worry about freezing temps. The cooling system is under pressure as has been mentioned, so even if the coolant is above the boiling point, it won't boil unless you lose pressure.

You could try some water wetter too but there's definitely something wrong with your system. Even with the bumper and lights etc it should run cooler.

Amazon.com

 

[AFei]

I run a mesh screen year round and have no issues.

I did think about the same type of setting. LOL glad to see I'm not so unique...

there's definitely something wrong with your system. Even with the bumper and lights etc it should run cooler

Good to know. Yeah, I believe something is wrong. I could feel that there is some capacity issue with the cooling system...

Burping air from system is key. Check under rad cap, before sun-up when coolest OAT of the day, after 8 hour engine cool down, while parked with front end higher than rear.

I did the burping process on the driveway where the front end is sightly higher. Will try again by but the front end on the ramp and see...

The process I followed was to turn on front/rear heat to max, and then keep engine at around 2000 RPM. Then burping the air by compress the upper hose. anything else I need to do?

Properly installed: thermostat (OEM, w/ jiggle value at top), rad cap, and proper working reservoir hose and its cap are all a must.

Yeah, I did replace with the OE thermostat about 20K miles ago, and installed with the jiggle valve at top. To be certain, I will remove it and inspect it as stated in the FSM to make sure it still functioning. Do you think a lower temperature (174 instead of 194) from RockAuto may help? Or even run without the thermostat in the desert summer?

The 06-07 use a different fan and fan clutch (thicker clutch, w/black mount flange). You mention major engine work. Make sure the FC and fan, was not switched to older style (FC has blue mounting flange).

My LX is 04 and it's still the old style I guess? The new clutch is the Asian FCT-021 . Do you think I can try the 06/07 style FC/Fan?

What are ECT, fuel trims and AT fluid temps readings. While on HWY, off road???

Right now I noticed the high ECT issue on highway, not on trail. I didn't do any hard tail either. The ATF temperature was at about 180F range according to the Torque Pro.

Fuel Trim is new to me and never heard/thought about it before. Just did a quick reading and found it's an important indicator. Will start monitor it...

Why were the heads R&R? Replaced with used or new heads? Used restored, and possible boiled?

The heads were warped and the coolant got into the cylinder. It's replaced with rebuilt heads, for the much cheaper cost... Job was done by the dealer and they inspected the rebuilt heads was good...

Consider thicker weight oil in your fan clutch (as previously mentioned). 15 or 20 CST. The new Aisin clutch I got came with about 5 CST. It's cheap and easy to change and makes a huge difference when the water temp gets up there.

I still have the old fan clutch. According to the paper test, it should work but I replaced it with Aisin one anyway. Guess it's a good candidate for rebuilding with thicker weight oil? I have gone through several threads on the fan clutch rebuild to get some idea. However, any tip or special note?

ONLY above 65 MPH. NEVER got hot under those speeds.

Mine did run some cooler at/under 65, but still at around 200

It may be worth monitoring fuel pump speed, if you find fuel trims running lean at higher RPMs, as ECT temp hit your highs.

How to monitor the fuel pump speed?

 

[azusa]

Before you go chasing your tail just remove the lights if it's not too much trouble, I would also remove the winch but that's probably more work than the lights. Recently had a customer with a newly purchased used Jeep, it had angry Bird aftermarket grill. Long story short after replacing a leaky radiator cap, went on the freeway to verify coolant temperatures. Not even 2 mi onto the freeway It was already 215f at 85° f ambient temperature. Drove for another 4 miles and it got into the 225s. Top radiator hose blew off the radiator. Got towed back to the shop and immediately remove the angry Bird grill. Went on another test drive with the old radiator cap that didn't hold pressure up to the spec and it never went up above 190. As you can see from the hood insulator that this must have happened a few times with the previous owner. This week the temperatures were 115 ambient got in touch with the customer gladly he reported temps to be between 190 and 205. The reason the hose blew off was a mystery to me. After I replaced the radiator cap because the old one couldn't hold pressure, on a hunch I recommend to replace the radiator. With radiator removed I could see the crack around the upper radiator hose outlet. With the new cap holding much higher pressure, the clamp had no chance of holding the hose in place.

 

[2001LC]

I did think about the same type of setting. LOL glad to see I'm not so unique...


Good to know. Yeah, I believe something is wrong. I could feel that there is some capacity issue with the cooling system...


I did the burping process on the driveway where the front end is sightly higher. Will try again by but the front end on the ramp and see...

The process I followed was to turn on front/rear heat to max, and then keep engine at around 2000 RPM. Then burping the air by compress the upper hose. anything else I need to do?


Yeah, I did replace with the OE thermostat about 20K miles ago, and installed with the jiggle valve at top. To be certain, I will remove it and inspect it as stated in the FSM to make sure it still functioning. Do you think a lower temperature (174 instead of 194) from RockAuto may help? Or even run without the thermostat in the desert summer?


My LX is 04 and it's still the old style I guess? The new clutch is the Asian FCT-021 . Do you think I can try the 06/07 style FC/Fan?


Right now I noticed the high ECT issue on highway, not on trail. I didn't do any hard tail either. The ATF temperature was at about 180F range according to the Torque Pro.

Fuel Trim is new to me and never heard/thought about it before. Just did a quick reading and found it's an important indicator. Will start monitor it...


The heads were warped and the coolant got into the cylinder. It's replaced with rebuilt heads, for the much cheaper cost... Job was done by the dealer and they inspected the rebuilt heads was good...


I still have the old fan clutch. According to the paper test, it should work but I replaced it with Aisin one anyway. Guess it's a good candidate for rebuilding with thicker weight oil? I have gone through several threads on the fan clutch rebuild to get some idea. However, any tip or special note?


Mine did run some cooler at/under 65, but still at around 200


How to monitor the fuel pump speed?

"I did the burping process on the driveway where the front end is sightly higher. Will try again by but the front end on the ramp and see...

The process I followed was to turn on front/rear heat to max, and then keep engine at around 2000 RPM. Then burping the air by compress the upper hose. anything else I need to do?"

Front end level or slightly higher, is good enough. Key is let engine cool down overnight, without removing rad cap. Until checking under the rad cap before sun-up, at coldest time of morning. Coolant should be to the very top of rad.

I only use OEM thermostat! I doubt using lower opening temp thermostat, will help with your issue. Since OEM is fully open, long before 200f.

I'm very interested to see if increasing air flow through bumper, makes any difference. I see many heavy built rig. With tons of stuff on bumper. I don't see ECT in the 200F. But we don't see 115f OAT either!

What I do see with heavy iron bumpers. Is they retain much more heat than OEM plastic bumper. Which we see on dash OAT read out. It can take 45 min for dash OAT to come down to actual OAT while driving.