1HD-FT overheating

[s13koop]

Chasing a random overheating problem. A bit of background. Owned it 3 years now and have taken it from Texas to CO, AR, and long road trips within the state.
The issue is it doesn't overheat everytime, in fact its only slightly risen in temps 3 times since I've owned it. Most notably after driving all the way to from Houston to Durango, CO, thru Silverton, Ouray, Lake City it started to creep on my way back in Dallas, the last 400mi of the entire trip.
Blasting the heater brings it back down to normal.
Second and third time I went to the Guadalupe River about 3hrs away, again, temps crept up only on the return home.
Its not my daily and city driving it maintains normal temp which is slightly below half on the gauge.
Engine is mostly stock with only a Trans Cooler and QIKAZZ 4x4 fan. Sitting at 298k KM
Upon delivery from port I noticed a new OEM Toyota radiator. (I flushed and added new Toyota red coolant when I got it)
I planned for some large maitenance items at 300km (injectors, pump, BEB, turbo, FMIC)

Are these rolling hills at 70-75mph fully loaded on 35s workin it too hard?

 

[GreenPump]

I planned for some large maitenance items at 300km (injectors, pump, BEB, turbo, FMIC)

You don't need to worry about BEBs on an FT.

Are these rolling hills at 70-75mph fully loaded on 35s workin it too hard?

Absolutely not. These are cold-blooded engines. Any overheating of a 1HDxx is unusual. Next thing to replace is your thermostat. I have seen them get stuck intermittently. PN# 9091603089 can be ordered from your local domestic Toyota dealer for <$25. Don't forget gasket #1634666020.

 

[s13koop]

I definitely ordered those items yesterday. Not sure if they were previously replaced.
I’ll install and do a long road test run.

 

[MonsterCruiser]

I had a similar issue with my 1HD-T and the problem was the old radiator was not flowing well. Overheating would only show up on long trips, and even then, longer drives with no hills I had no overheating.

 

[s13koop]

I had a similar issue with my 1HD-T and the problem was the old radiator was not flowing well. Overheating would only show up on long trips, and even then, longer drives with no hills I had no overheating.

Yea thats basically Texas, no real hills but indeed long and slightly climbing. I started to think radiator even though its new but I double checked and its indeed an OEM Toyota rad.

 

[GreenPump]

I had a similar issue with my 1HD-T and the problem was the old radiator was not flowing well.

I second this.

You may as well replace the radiator too. After 30 years, a lot of them are physically deteriorating.

Order an Agility #8011469 on RockAuto. It will run you <$250, fits perfectly on 1HDT trucks. I've installed two of them and the quality is pretty good.

 

[TreadingLight]

Do you have a mechanical fan w/clutch? My failed fan clutch was the culprit for my intermittent overheating.

 

[s13koop]

I second this.

You may as well replace the radiator too. After 30 years, a lot of them are physically deteriorating.

Order an Agility #8011469 on RockAuto. It will run you <$250, fits perfectly on 1HDT trucks. I've installed two of them and the quality is pretty good.

Do you have a mechanical fan w/clutch? My failed fan clutch was the culprit for my intermittent overheating.

The radiator was replaced in Japan at some point before it shipped. I noticed it immediately when I took delivery. Toyota stamp and part# confirmed it was OEM (also it was the cleanest thing in the engine bay lol)

Yea I replaced the stock fan with an aftermarket QIKAZZ 4x4 fan clutch w/mitsubish fan blade. Noticeable louder but not terrible.

 

[rick_d]

Poor coolant maintenance over decades can cause internal corrosion to build up especially in the oil cooler (behind injection pump). An Oxalic acid (wood bleach) flush followed by neutralization with Baking soda helps as well as physical removal and cleaning of the oil cooler post flush. The procedure of the flush is well documented and was based on a General Motors service bulletin for in dash heaters. Brass radiators may do better than aluminum/plastic on the flush but there is little study on effects of oxalic acid on those later radiators.
Fan clutch replacement may also be in order.
I use "blue" E-2014 Mercedes Benz coolant which has a good reputation with machinists on internal corrosion control on cylinder blocks.
Evans waterless coolant is also been suggested but does require some prep to introduce.

I ran my hdt for several years after installation in 2006 and then suddenly in 2010 ish I went on a vacation and began throwing clots into my radiator 100 miles from home. Essentially boogers from the oil cooler cut loose and blocked off a large portion of radiator. Sheldon Walsh also had a similar incident after diesel converting an 80 series.

 

[s13koop]

Poor coolant maintenance over decades can cause internal corrosion to build up especially in the oil cooler (behind injection pump). An Oxalic acid (wood bleach) flush followed by neutralization with Baking soda helps as well as physical removal and cleaning of the oil cooler post flush. The procedure of the flush is well documented and was based on a General Motors service bulletin for in dash heaters. Brass radiators may do better than aluminum/plastic on the flush but there is little study on effects of oxalic acid on those later radiators.
Fan clutch replacement may also be in order.
I use "blue" E-2014 Mercedes Benz coolant which has a good reputation with machinists on internal corrosion control on cylinder blocks.
Evans waterless coolant is also been suggested but does require some prep to introduce.

I ran my hdt for several years after installation in 2006 and then suddenly in 2010 ish I went on a vacation and began throwing clots into my radiator 100 miles from home. Essentially boogers from the oil cooler cut loose and blocked off a large portion of radiator. Sheldon Walsh also had a similar incident after diesel converting an 80 series.

I looked into possibly pulling the oil cooler off but damn, per the FSM I have to tear down the whole front timing gears?? Visually is the oi lcooler seems to be out of the way of that.

 

[rick_d]

hd-t require pulling pump that does not effect the timing gears.
There is no way on earth to remove the cooler and cover without the pump being removed.



this is typically what a bad cooler looks like.

 

[mudgudgeon]

Are these rolling hills at 70-75mph fully loaded on 35s workin it too hard?

No. Something is wrong.

Yea I replaced the stock fan with an aftermarket QIKAZZ 4x4 fan clutch w/mitsubish fan blade. Noticeable louder but not terrible.

Seriously consider going back to an OEM fan clutch and fan blade. No aftermarket product maker tested their fan and hub more rigorously than Toyota did.

I would put money on poor fan performance being the single biggest cause of overheating in all landcruiser models.
The OEM fan and hubs are hard to beat, as long as the hub is working correctly so the fan can work at full capacity.

On hot days, working hard, you still need an effective fan at highway speeds.


Beyond that, consider installing an EGT gauge so you can get a read on the state of tune for your fuel injection pump. If someone has messed with it for more power, it could be running a hot tune. (excess fuel equals more power, but also high combustion temperatures).

You said you replaced coolant. Did it have red coolant in it? Or green?
Mixing the two is incompatible and can create hard sediment to form in the coolant. This can clog radiators cores, heater cores, hoses, thermostats etc

 

[Squash]

What is your definition of hot?
On long climbs i drop a gear, increase rpm, and hold rpm after the crest just to cool things down again.
My 1hz will run from 165f to over 200F depending on terrain.
She has 530,000 on her odometer.
Have an 1hdt and 1HD-FT as well.
All three get the same treatment.
If you consider glycol, 14.5 psi rad cap and decent cooling system which does not leak you can easily handle 220F .
Besides, a bit of heat keeps the combustion chambers clean of soot.

 

[TheBussman]

how hot is it?

 

[s13koop]

No. Something is wrong.



Seriously consider going back to an OEM fan clutch and fan blade. No aftermarket product maker tested their fan and hub more rigorously than Toyota did.

I would put money on poor fan performance being the single biggest cause of overheating in all landcruiser models.
The OEM fan and hubs are hard to beat, as long as the hub is working correctly so the fan can work at full capacity.

On hot days, working hard, you still need an effective fan at highway speeds.


Beyond that, consider installing an EGT gauge so you can get a read on the state of tune for your fuel injection pump. If someone has messed with it for more power, it could be running a hot tune. (excess fuel equals more power, but also high combustion temperatures).

You said you replaced coolant. Did it have red coolant in it? Or green?
Mixing the two is incompatible and can create hard sediment to form in the coolant. This can clog radiators cores, heater cores, hoses, thermostats etc

As far as I know the pump is bone stock but I do need to get an EGT in there to get some data.
I went with Toyota Red 00272-1LLAC-01 per Muds suggestion.
But yea, it just doesn't do it all the time, only on these long trips and even still its on the way back. its also 100+ in Texas right now

 

[s13koop]

What is your definition of hot?
On long climbs i drop a gear, increase rpm, and hold rpm after the crest just to cool things down again.
My 1hz will run from 165f to over 200F depending on terrain.
She has 530,000 on her odometer.
Have an 1hdt and 1HD-FT as well.
All three get the same treatment.
If you consider glycol, 14.5 psi rad cap and decent cooling system which does not leak you can easily handle 220F .
Besides, a bit of heat keeps the combustion chambers clean of soot.

I really need to get an aftermarket gauge but the stock needle is climbing above 1/2 way.

 

[TreadingLight]

You can really only judge the needle relative to it's own past behavior.

On my 1hz I wouldn't pay it any attention just for reading above the halfway mark. It would have to go sky high before I considered it a problem.

 

[TheBussman]

on a 80 series it has to get pretty damn hot to go above 1/2 way, the gauge mod is totally worth it. Makes it read like a 60 or 70 series.

 

[mudgudgeon]

It would have to go sky high before I considered it a problem.

The problem with the stock temperature gauge, "sky high" usually means you are already past the point of avoiding a potential catastrophe

 

[TreadingLight]

That's not been my experience. I can pretty clearly tell the difference between needle behaving like normal and needle climbing high. The OP reports "slightly risen in temps 3 times" and that sounds pretty normal.

The real variable is how close you're paying attention.

If you're stock, this is all pretty predictable. If you're modded to the ragged edge of heat limits then you need more accurate gauges and alarms.