94SRUNNER
GOLD Star
These coolant temperatures you have listed above, as well as the behavior of the observed coolant temp fluctuations, IMO are completely normal and I see similar patterns in my system.
Nothing to worry about.
2UZ-FE Normal Operating Temperature (3 Viewers)
- Thread starter Rpreme
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
These coolant temperatures you have listed above, as well as the behavior of the observed coolant temp fluctuations, IMO are completely normal and I see similar patterns in my system.
Nothing to worry about.
2001LC
SILVER Star
What's your mileage?
In the mile high city. I'd say your running hot. But regardless of altitude. That rapid ECT fluctuation, on a cool evening in lower RPM and speeds, is not what I'd see after a complet baseline. In a stock 98-02 with engine, properly turned and all but lower foam around radiator. I'd see 184-187F ECT in most all driving condition from 5,000' to 9,000' ASL. W/both AC on full or off, at OAT between 60F & 97F.
Did you clean your radiators fins (all 3). I see no mention of doing so.
forum.ih8mud.com
Fan clutch can be difficult to diagnose. Additionally they may build up crud on the face of fan in the coil. This can interfere with coils operation. Clean it as you clean the radiators. It can take hours and repeated attempts to clean the radiator fins. Really take the time to do a thorough job and come back often at it.
New radiator OEM cap is a must.
Confirming the tube and cap between radiator and reservoir, is free of obstruction. Confirm reservoir tube goes straight the the bottom of reservoir. Very important.
The fact you replaced water inlet & cap. Suggest to me, you had electrolysis. That is a system that was not well care for with all OEM products from day one.
I only use, Toyota red mixed 50/50 with distilled water in the 89-03. Additionally in older systems. It's not a bad Idea to chemically flush with BG Clean and add BG Cool. Make sure block is triple drain and blow out the system each flush/drain.
On other notes:
I notice your BK 1 LT FT reading in the negative. whereas BK 2 LT FT running a more normal to what I see, in positive. I'd run BG44k in halve tanks of gas (about 12 gallons) and Chevron techron in another. Alternating one bottle at a time, for 4 tanks. Or better better yet; rebuilt all fuel injectors, replacing all seals. Making sure top of engine is spotless before doing so. You do not want even dust dropping into intake ports. Replace fuel filter also. Additionally verfly not vacuum leaks. This includes the two vacuum lines coming up from idle up control of vane pump (power steering pump).. Replace fuel filter if never done, is good PM.
forum.ih8mud.com
Has starter ever been replaced. Were intake gaskets replaced at that time. Was top of engine cleaned before doing so. A compression check, can be revealing. So very often shops or even more so DYI ,drop sand down the intake ports from not clean top of engine pre disassemble..
BTW: Did you replace PCV grommet. 98-02 grommet shrink and we lose vacuum and blow oil out around grommet.
What's condition of spark plugs and coils.
forum.ih8mud.com
forum.ih8mud.com
Make sure you've a good OEM air filter and seal of filter did not get pinched.
Don't get frustrated, just get all systems back to spec. Frustration starts when they are.
In the mile high city. I'd say your running hot. But regardless of altitude. That rapid ECT fluctuation, on a cool evening in lower RPM and speeds, is not what I'd see after a complet baseline. In a stock 98-02 with engine, properly turned and all but lower foam around radiator. I'd see 184-187F ECT in most all driving condition from 5,000' to 9,000' ASL. W/both AC on full or off, at OAT between 60F & 97F.
Did you clean your radiators fins (all 3). I see no mention of doing so.
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...
forum.ih8mud.com
Fan clutch can be difficult to diagnose. Additionally they may build up crud on the face of fan in the coil. This can interfere with coils operation. Clean it as you clean the radiators. It can take hours and repeated attempts to clean the radiator fins. Really take the time to do a thorough job and come back often at it.
New radiator OEM cap is a must.
Confirming the tube and cap between radiator and reservoir, is free of obstruction. Confirm reservoir tube goes straight the the bottom of reservoir. Very important.
The fact you replaced water inlet & cap. Suggest to me, you had electrolysis. That is a system that was not well care for with all OEM products from day one.
I only use, Toyota red mixed 50/50 with distilled water in the 89-03. Additionally in older systems. It's not a bad Idea to chemically flush with BG Clean and add BG Cool. Make sure block is triple drain and blow out the system each flush/drain.
On other notes:
I notice your BK 1 LT FT reading in the negative. whereas BK 2 LT FT running a more normal to what I see, in positive. I'd run BG44k in halve tanks of gas (about 12 gallons) and Chevron techron in another. Alternating one bottle at a time, for 4 tanks. Or better better yet; rebuilt all fuel injectors, replacing all seals. Making sure top of engine is spotless before doing so. You do not want even dust dropping into intake ports. Replace fuel filter also. Additionally verfly not vacuum leaks. This includes the two vacuum lines coming up from idle up control of vane pump (power steering pump).. Replace fuel filter if never done, is good PM.
When to Clean or Replace fuel injectors
Please post your experiences and thoughts on the subject. I’ve been considering cleaning or even replacing all 8 fuel injectors, is this wasting time and money. I understand keeping fuel injector clean by adding a can of additive to the gas tank, now & then, is a good practice. This keeps them...
forum.ih8mud.com
Has starter ever been replaced. Were intake gaskets replaced at that time. Was top of engine cleaned before doing so. A compression check, can be revealing. So very often shops or even more so DYI ,drop sand down the intake ports from not clean top of engine pre disassemble..
BTW: Did you replace PCV grommet. 98-02 grommet shrink and we lose vacuum and blow oil out around grommet.
What's condition of spark plugs and coils.
Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!
TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...
forum.ih8mud.com
When to replace Ignition coils.
As our 100 series fleet ages we're seeing more ignition coil failures. Is there a certain mileage or age where our 100 series with the 2UZ-FE engine are seeing the need to replace one or more ignition coils? If you’ve replaced any coils please post any performance differences before & after...
forum.ih8mud.com
Make sure you've a good OEM air filter and seal of filter did not get pinched.
Don't get frustrated, just get all systems back to spec. Frustration starts when they are.
Last edited:
I may be able to help with this, within the next week or so. I would expect mine to do the same thing. Gain a few degrees going up mild hills, and then back down. I am currently in the middle of a cooling system overhaul. So once I am back on the road, I will report back.
shtbrwn86
SILVER Star
That would be great. But the more I think about this the more I think about how many 100 series drivers are out there just happily tooling about in their ignorant bliss and the ECT temps go up and down but they never know any better because it's not moving the needle and while it might be running hotter than a new truck it's still not in the danger zone.
Tru dat. But two sayings to think about.
Ignorance is bliss.
Knowledge is power.
Pick one of the two, and live with results.
2001LC
SILVER Star
@gungriffin runs with TRD. He also has lower temp thermostat as you and different spark plugs than stock. IIRC he's running cooler than you.
Me? I'm not worried at all about my temps; just providing another data point.
Good to know!
Didn't read the whole thread, but make sure your radiator is clean. I had a customer come in for a timing belt in a extremely clean 2006 LX with 180k for a timing belt. Radiator looked great on the back side. Once I pulled it, it looked like this. The condesor being sandwiched against the front of the radiator can really trap grime. You can't even get to this section with a hose because of the fan shroud.
2001LC
SILVER Star
I see the same, time and time again. I now regularly clean radiator as I clean engine before timing belt job. As part of coolant system service. Sometimes hours of HP washing, come back again and again from all angles. Even after all that washing, I find they (all 3 radiators) need more cleaning after I pull the engine radiator.
Even with skid on, a flashlight will reveal the cloggs.
I've even found styrofoam between them, with full skids on and all foam. I suppose standing in high water and floated in.
forum.ih8mud.com
Even with skid on, a flashlight will reveal the cloggs.
I've even found styrofoam between them, with full skids on and all foam. I suppose standing in high water and floated in.
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...
forum.ih8mud.com
How was it replacing the crank seal? I think I need to replace mine. I have the fan and shroud off right due to replacing the clutch. I am seeing oil down there.
I see the same, time and time again. I now regularly clean radiator as I clean engine before timing belt job. As part of coolant system service. Sometimes hours of HP washing, come back again and again from all angles. Even after all that washing, I find they (all 3 radiators) need more cleaning after I pull the engine radiator.
View attachment 2454104
Even with skid on, a flashlight will reveal the cloggs.
View attachment 2454102
I've even found styrofoam between them, with full skids on and all foam. I suppose standing in high water and floated in.
View attachment 2454108
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...
Did a longer road trip today only up to 4k feet but Temps were just shy of 100. Even idling with a/c on the ect temp did not get above 190 degrees and while driving was in the 181-186 range primarily. I was seeing over 200 before I replaced the fan clutch a while back few weeks ago. Also replaced the lower and upper rad hose and water inlet so one of those had something to do with it. I was seeing trace amounts of coolant on the water inlet I think from lower rad hose micro leak. This is an 06 LX
2001LC
SILVER Star
Good info thanks. That lower than 98-02's 184-187F. OAT of 100F, ECT 181-186 is a few degrees lower than I'd expect. Fan clutch, for sure would have been your greatest factor in reducing ECT.
I Don't recall. Any of below done or replaced:
Thermostat
Radiator Cap. Radiators fin washed out.
All vacuum line checked. leaky ones replaced.
Yes all of that has been done. OEM cap, oem tstat both new. replaced several vaccum lines, pcv valve, fuel filter, fuel pump, fuel pressure regulator. washed radiator fins. going to add the skids back on soon will update with new numbers but ambient temps will be cooling down soon
2001LC
SILVER Star
So I see this is a very good example of ECT in a properly tuned & running VVT 06-07 with very mild build (ASFIR Skid). 181-186F w/OAT of 100 AC on in the sun. at SL (Sea level) to 4k ASL. I assume side and top foam around radiator.
Thanks so much for posting. Getting these base line or important.
Thanks so much for posting. Getting these base line or important.
2001LC
SILVER Star
So it's looking more and more like; all stock 100 series. ECT 184-187F (+ or- a few degree f) is normal.
Yes foam on radiator all around, but front skid was not on for these numbers. My next Temps will be with sliders installed as well as front rear and mid skid I'll report back. Lt fuel trims are around 0.75
If I had a large audience I certainly wouldn't be advocating people spend money chasing the lowest temp possible.
Half the audience probably thinks the temp gauge is oil related in the first place, 20 year old sensor an'all. What's the +or- number again?
Half the audience probably thinks the temp gauge is oil related in the first place, 20 year old sensor an'all. What's the +or- number again?
Found this new Aluminum option. Who's going to be an early adopter test pilot......
www.mishimoto.com
Performance Aluminum Radiator, fits Toyota Land Cruiser J100 (2UZ-FE) 1998-2007
If you're looking to upgrade your Toyota J100 cooling, look no further! The Mishimoto 1998-2007 Toyota Land Cruiser J100 Performance Aluminum Radiator is an ideal upgrade for the brittle stock radiator. Our radiator boasts a 19% greater core volume and 26.5% greater coolant capacity to improve...
www.mishimoto.com
