Engine Coolant Temperature 208F

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Porzingis213

Porzingis213

Joined
Jun 24, 2020
Threads
11
Messages
48
Location
Oregon
Hello, I need some advice on my 2000 271k miles LC.

Some background, this past summer car was fully loaded on a long drive to Texas from Arizona, in the long steep hills outside the valley of Arizona the dash temp gauge was getting real hot close to the red but never touched the red, so I pulled over a few times and let it cool and continued my drive, I did not think much of it. The car was fine for the whole summer and on the way back to Arizona again on the same hills same problem. Again I didn't think much of it. About a month ago I took the car camping, car was fully loaded and it was getting really hot at highway speed or any hill. Now I started thinking what is wrong with this car. This problem seems to only happen when the car is fully loaded and with decent load.

I started by using a head cover gasket leak detector, one of those ones you put on top of the radiator and you wait to see if the color of the liquid changes, no sign of bad head gasket from this test. I then bought a obd2 live scanner to read what my engine coolant temp was sitting at on a normal load/drive, it was at 223F. This from what I have read from others is pretty hot and I'm not sure how long its been at this temp. After this finding, I went to change the thermostat and found a leak behind the thermostat housing. I fixed the leak and put a new thermostat and radiator cap. Now the temperature is sitting around 205-210F. The fan clutch is only a couple years old and I can hear it roar after a bit of gas. The radiator is aftermarket and probably 6-8 years old.

I need some advice, should I keep digging to get my temps lower than 205-210F? Or should I wait probably till sometime in the next year or two when I replace the timing belt.
My worry is that I will be driving this car from Arizona to Oregon this summer and thats a pretty long drive with many hills along the way.

Thank you in advance for any help!
 
2001LC

Thread 'Radiator fins need cleaning! Alert Alert Alert'

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added radiator cap and thermostat to job, as best practice.

Got me to thinking about the radiators I've been replacing. All have debris built up on lower third.
This one hand some extra grasses along with general clogging on lower third.
Radiator Clog (3).JPG

Over the years/miles debit builds up in condenser and...
  • Like
 
Every photo of a radiator that's been pulled from these vehicles has shown substantial fin clogging.

Pulling the radiator for backflushing the fins (and backflushing the condenser coil) should be PM every 3-5 years when the coolant is replaced, IMO.
 
I did push back the radiator shroud and clean the radiator with AC condenser cleaner a few times and no change in temperature. Can I get access to the condenser to clean without removing the radiator? I used the garden hose on full jet from the front for the condenser and from the rear for the radiator.
 
If your cooling system looks good, I would order a new fan clutch and fan and refill the clutch with 30k cst of viscous fluid, especially in Arizona.

LostAfrican

Thread 'hundy fan clutch - should I re-oil for idle temps?'

Hi,
Any of you do the fan clutch mod on a hundred? Worth it? Advisable?

Our LX470 engine coolant temp climbs above 200F even above 205F if I let it, idling in a line of cars at the border. I am not happy that the engine can't cool itself to optimal temp when idling. Admittedly it's sitting there running the AC in a hot environment for an hour or more.

I have a blue clutch (a spare one even) and after reading the threads am contemplating changing the oil to 25K CST. Should I also re-index the aperture?
Good idea?

Our LX is an 01 with the OEM AC condenser fan, which does come...
 
Make sure:
  • Fan clutch working as in it should.
  • Thermostat is OEM, with jiggle valve at top/up.
  • Reservoir and it's hose working as should. I've seen some clogged and many hose curled uppward.
  • Good OEM rad cap.
  • No air in system. Looking under rad cap, after 8 hr. cool down with vehicle cross level and front end higher than rear. Check, at coldest time in day/AM before sun warms the air.
  • Engine properlly tuned.
  • Monitor fuel trims. A lean fuel condition, increase cylinder head temp.
  • Monitor AT ATF temp. Make sure good oil and ATF at proper levels.
  • Verify ECT seen via tech stream. With IR gun on back side of water inlet cap (thermostat). Get gun within 3" or closer, proptect from air flow of fan. Expect to read a few degrees F lower at gun. It rare, but a water temp sensor reads wrong, but can happen. Also look ECT sensor wires for damage.

Notes:
Any unusal color in any part of coolant system. That may indicate a stop leak added. I often see a brown color when stop leak added.
 
Hi All,

I have a finding that I want to run by you guys, I had my coolant temp sensor replaced this past summer by a shop in Texas while trying to fix a stalling issue. I noticed that the sensor he replaced it with is black not green like the one he pulled out, I believe the black sensor is 89422-30030 and the one that should be in my car is 89422-20010. My car is a 2000 Land Cruiser manufuctured in 02/2000. Do you guys think this could be what is causing my ECT to read high this whole time?
 
Per Partsouq:

1774468472213.webp


They appear to be interchangeable based on aftermarket info.

My bet is it's not the sensor.

I've been dealing with running hotter than spec for a couple years, and finally found my radiator had a slow leak by using UV dye. It was weeping out of the top cap once pressurized at operating temp. I guess the lack of pressure build allowed it to run hotter. Have you still been losing coolant after the thermostat fix?
 
Dirt J said:
Per Partsouq:

View attachment 4109340

They appear to be interchangeable based on aftermarket info.

My bet is it's not the sensor.

I've been dealing with running hotter than spec for a couple years, and finally found my radiator had a slow leak by using UV dye. It was weeping out of the top cap once pressurized at operating temp. I guess the lack of pressure build allowed it to run hotter. Have you still been losing coolant after the thermostat fix?
Click to expand...
Thanks for sharing. I have a new sensor coming but I am probably going to check with UV dye as well to see if my rad has any leaks. What temp were you running while trying to fix your rig?
 
I saw as high as 220+ last summer. I chased this with a new radiator cap and fan clutch. I was losing coolant but no head gasket leak. Thought maybe is was heater core but no wet floor. Also replaced the oil cooler gaskets when doing my rack. There was oil and/or coolant seepage there too. Because there was no large, obvious leak it stumped me for a long time. Never considered small leaks (that essentially vaporize once at operating temp).

My attempt at pressure testing failed, or that probably would have caught it sooner.

This is the dye I used. They had a cheap pen blacklight at the counter. Drove it a few days and the dye showed up great at night with the penlight.
 
Dirt J said:
I saw as high as 220+ last summer. I chased this with a new radiator cap and fan clutch. I was losing coolant but no head gasket leak. Thought maybe is was heater core but no wet floor. Also replaced the oil cooler gaskets when doing my rack. There was oil and/or coolant seepage there too. Because there was no large, obvious leak it stumped me for a long time. Never considered small leaks (that essentially vaporize once at operating temp).

My attempt at pressure testing failed, or that probably would have caught it sooner.

This is the dye I used. They had a cheap pen blacklight at the counter. Drove it a few days and the dye showed up great at night with the penlight.
Click to expand...
Good to know. I’m really not losing coolant but I still may put some dye in to rule out a small leak.
 
I like to start, by monitoring: Fuel trim, ECT, ATF temp. lean fuel condition, increases cylinder head temp. If ECT increases, while stop at red light. Than drops as we driving. It's likely Air Flow issue. ATF running hot, adds to coolant radiator heat.

Coolant leaks, resulting in pressure loss. Doesn't result in higher ECT due to low system pressure. Stuck rad cap, result in higher pressure, which kicks up ECT. Higher pressure, increases heat.

Stuck or slow opening thermostat, result in higher ECT.

leaks result in low coolant level and air in system. Which result in higher ECT.
leaks may also result in vacuum lose during cool down. Which result in resevoir not functioning properly.

2001LC

Thread 'Radiator fins need cleaning! Alert Alert Alert'

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added radiator cap and thermostat to job, as best practice.

Got me to thinking about the radiators I've been replacing. All have debris built up on lower third.
This one hand some extra grasses along with general clogging on lower third.
Radiator Clog (3).JPG

Over the years/miles debit builds up in condenser and...
  • Like
 
you're not going to find small leaks on a 100 without removing the intake and pressure testing from there. You will find ANY leak pressure testing with it off.
 
Easy way to check if the sensor is reading accurate is to check the temperature when you first start the truck for the day, engine temperature should match ambient.

It should run under 200F easily when just driving normally. I didn't see you mention draining and replacing the coolant, I'd definitely do that, and maybe flush the engine and rad with the garden hose before refilling. If the rad is 6-8 years old the coolant probably is too, or could be mixed with even older coolant.

Lastly it could be a weak water pump if it's got a ton of miles on it.
 
jerryb said:
you're not going to find small leaks on a 100 without removing the intake and pressure testing from there. You will find ANY leak pressure testing with it off.
Click to expand...
Can you ellaborate, are you talking about a coolant pressure test?
 
IMG_1438.webp

I know there is a procedure to checking the transmission fluid so not sure if I did it correctly. I drove the car on the highway for 20 minutes, parked on my flat driveway, and ran it though all the gears, then I let it sit for 5 minutes and checked the level. It is above the hot full line, what do you guys think?
 
because the leak is going to occur a t the rear crossover pipe, or the back end, or under the intake.
for the end all be all coolant leak test it needs to be with the intake off, make sense?
the small ones you guys are talking about are there, not at the rad or the overflow tank.
 
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