Help. On the verge of despair 1FZ-FE overheating on flat highway over 60 miles (1 Viewer)

[Desert Dino]

Hi


Just finished my baseline and build spent a fortune on the rig and started going over landing
Over landing basically its 2 or 3 days, 100 miles on highways and country roads from home to the Negev Desert 50 miles on the trail each day with some technical rock crawling and passes and then 100 mails back home

Most of the driving in the desert is allowed only during the day, at night we have to go approved Campgrounds

Now its winter so ambient temp during the day will be 18-24 C (65-75 F) so its cool and nice

I measure engine temp by two ways
1. OBD temp
2. External engine skin temperature
Both measurements coincide with some delay on the external unit

Here is what I found

Miles temp C temp F
50 84 183
60 86 187
70 88 190
80 90 194
If there is hill, it will go 92-93 (198F) and I have seen 95 (203F) for very short time the temp change is fast up and down

Reducing speed will make the engine cooler very fast

This is winter this rig wouldn't survive the spring and summer temps will go up to 104F

This is overheating phenomenon that nobody here knows what to do with it most of old rigs overheat in low speeds not enough wind in the radiator not enough water circulation in low RPM the water pump moves less volume

All the engine cooling system is brand new including oil cooler. And I am using Toyota red

I have read everything on MUD it looks like 1fzfe problem of not enough coolant circulation

The things I do not know
* The position of the hole in the thermostat

Things to do
*Vents on the engine hood
*Blue fan clutch mod but this is negligible at high speed

Things I may do
Engine cooling system flush PO used tap water
i was advised against this!!

Open to any suggestions

 

[retrofive]

Higher CST and black hub would be on my list.
Pulling and testing the t-stat would be be on my (regardless if new or replaced)

Those temps don't sound bad (read not overheating), and may not reflect in the summer either. That is about what my truck run year 'round in the those temps.

 

[LFD2037]

Those temps mirror mine in winter 30*(now) and summer 100*.
Check t-stat
Check fan shroud
Check coolant/water ratio
Check fan performance

 

[fz1boxer]

water pump cavitating,make sure all the air is purged,higher pressure radiator cap,change thermostat even if its new.
i have taken 3 new thermostats and used heated water to check opening temp,there was a 12 degree difference between all three.
same brand of t-stats all 3 180 degree stats.

 

[landtank]

*Blue fan clutch mod but this is negligible at high speed

actually not!

 

[jeremy56]

I wouldn't even worry about those temps...it sounds like your system is working with the way it goes down fast when decelerating. If it was staying hot I would be more concerned.
Mine is rebuilt and all new cooling system, goes up to 219 on summer mountain drives but will quickly go back down to 180s as I crest the hill and go down.
Normal flatter hwy gets up to about 195 or a bit higher depending on rpm.

 

[Dragos80]

Those temps look normal to me.

 

[OGBeno]

^^^

Normal.

 

[BILT4ME]

@landtank stated the key.

I personally have not done it noticed, but I have read many threads here that state and show that the fan clutch in these is more required at highway speed than at low speed.

Your next check or change should be your fan clutch.

 

[gummycarbs]

Those temperatures look great to me. If anything, they're on the cool side until mile 90.

It's fine to flush a cooling system with tap water so long as you finish with a distilled water flush. In fact, the last time I flushed an engine, I can't even imagine how I could have done it without tap water. I needed the volume and pressure to wash all the crud out!

 

[jonheld]

*Blue fan clutch mod but this is negligible at high speed

NO. NO. NO. Exactly the opposite. The higher the speed, the more air flows AROUND the front of the truck. The fan creates negative pressure behind the radiator and draws air through. A weak fan clutch will almost always cause a temperature spike at highway speeds.

 

[flintknapper]

actually not!

actually not!

^^^^^^ Agreed.

I think folks mistakenly hold to the old axiom 'a fan is not needed above 35 mph', or the notion that it at best does little good.

Undoubtedly, with some vehicles this is true. Not so...with the Land Cruiser.

Owing to complex issues of air flow and aerodynamics (the Land Cruiser is about as aerodynamic as a brick), pressure can build up in the engine compartment. The fan helps evacuate that volume/pressure allowing more air to flow through.

If you disbelieve, remove your fan and go for spin on the highway (in ambient temps where the fan is needed).

 

[Tools R Us]

Normal. If you look at the specs for the thermostat, fully open is @200f, so until then some coolant is bypassing the radiator. At times of motor load, it's normal to see 200F ish temps. If you are running a stock blue hub, they are wimpy, best to change to a higher viscosity fluid, especially for desert conditions.

 

[NLXTACY]

If I didn’t know better, it would seem like you were at your absolute wits end

Not that I have any experience with overheating but I’d say it’s not abnormal.

 

[bjowett]

Temps sound fine. Get the tap water out. Make sure things are clean in the block and radiator. Given the ambient temps there, you can probably run 70/30% water to coolant and gain some breathing room.

 

[-Spike-]

The tap water isn't even that big of a concern. Yes, it's better to use distilled to fill the system if you have it, but how much solid material do you think is in your tap water? And flushing with distilled is a hilarious notion. People act like tap water is going to plug your cooling system on contact. Think logically.

x187 on temps sound fine. Save the despair for when you actually have an issue.

 

[retrofive]

The tap water isn't even that big of a concern. Yes, it's better to use distilled to fill the system if you have it, but how much solid material do you think is in your tap water? And flushing with distilled is a hilarious notion. People act like tap water is going to plug your cooling system on contact. Think logically.

x187 on temps sound fine. Save the despair for when you actually have an issue.

Remember his location... Isreal. I don't know the tap water quality there, but could be a lot worse than some places here. I don't know.

 

[-Spike-]

Remember his location... Isreal. I don't know the tap water quality there, but could be a lot worse than some places here. I don't know.

He says the PO used tap water for a flush. Unless he flushed it with sand, it's a non-issue. And I suspect Israel has the tech to at least allow their water to sit awhile and let the solids settle out before they use it. Hell, they might even have water treatment plants.

 

[retrofive]

He says the PO used tap water for a flush. Unless he flushed it with sand, it's a non-issue. And I suspect Israel has the tech to at least allow their water to sit awhile and let the solids settle out before they use it. Hell, they might even have water treatment plants.

Very true.

 

[LFD2037]

Remember his location... Isreal. I don't know the tap water quality there, but could be a lot worse than some places here. I don't know.

Probably like Flint, Michigan.