1HZ overheating again, this time in Argentina!

[Blade]

Hi guys

I am now in Argentina and the car is again starting to overheat often.
I really thought I had the problem solved in Ecuador, but it seems that it's back again and this time I am really out of ideas!!!

Story:
I started the trip in 2012, about 100'000km ago in Canada and up to Mexico I could drive the car from ocean to 4000m on steep hills and it would never see more than 100Celcius oil temp! Watertemp I don't know, I had the stock gauge back then.
In Central it slowly started to get hotter when climbing hills, but was still ok. In Ecuador it was so bad, that it reached on regular hills 130Celcius oil and 110+ water and smoked out of the overflow bottle!
Changed everything, did not help. Changed the injectors (80k old) and it ran much cooler! I thought the problem is solved. Now I am again back to having problems...

Maybe some of you still have an idea?

Here again the facts:

Car: HZJ75 with about 3.6-3.8 tons, depending on water & fuel.

Engine: 1996 1HZ engine with about 200'000km. Rechecked valve lash about 25'000km ago and it was at max. end play on all valves.

Turbo: All American Turbo, about 100'000km, 8psi boost. Oil cooled.

EGT gauge: can go up to 700Celcius PRE-Turbo, but I always keep it at 550Celcius max 600Celcius constant temperature

Injectors: rebuilt set with Denso parts in Peru about 5'000km ago

Injection Pump: rebuilt about 80'000km ago at Fred Holmes in Vancouver, Canada.
Installed a boost compensator and adjusted the fuel delivery to be slightly higher than stock 1HZ due to the Turbo. Not touched since then!

Injection timing: I set it 15'000km ago to max. value as specified in FSM. That means max. advancing within FSM spec. (I think that was around 1.09mm or so)
Thermowax works fine, I just checked again and when hot it is all the way out.

Fan clutch: I just put 2 bolts through it! After removing it 6 times I was sick of it and thinking that it MIGHT be the fan clutch so I fixed it now to 100%!! Helped ZERO!

Radiator: australian northern radiator, 4 row brass. s*** quality, had to remove it 4x already due to leaks, but 15'000km ago it was completly open at a radiator shop and the guy said it looks new inside. Radiator cap about 30'000km old, japanese made.

Shroud: stock one

Radiator hoses: stock Toyota. Bottom one reinforced with spring inside, just to be sure.

Thermostat: 15'000km old, new Toyota installed.

Waterpump: 15'000km old, new Toyota installed

Timing beld: 15'000km old, new Toyota installed

Coolant: always Toyota RED in 30-50% concentration, depending how much coolant I loose due to overheating or radiators leaks. Top up with destilled water.
Checked coolant for acid 15'000km ago when it was overheating hard and it was neutral.

A/C: stock setup, although does't run when having overheating problems, but the cooler surely doesn't help airflow!

Brakes: checked again, don't overheat! Free spinning wheels

Diesel: right now 500ppm sulfur in Argentina and what I read about 46 Cetane.


Bad things:

Winch in front of grill
bug-mesh on front grill
A/C cooler in front of cooler
missing hood rubber seal that seals between hood and radiator support



Here a few driving setups of the last few days where I went offroading in 3000-5000m altitude!
Very low tire pressure, gravel road:

Going uphill, 60kmh, 3rd gear, 2500RPM at about 4000m elevation
EGT 550Celcius constant
Air temp about 30Celcius
Oil temp 105Celcius
Water temp 95Celcius

Flat, 80kmh, 5th gear, 1800RPM at about 3500m
EGT 550Celcius constant
Air temp about 28Celcius
Oil temp 93Celcius
Water temp 85Celcius

4000-5000m uphill, 2nd gear, 2500RPM
EGT 500Celcius constant
Air temp about 5Celcius
Oil temp 100Celcius
Water temp 80Celcius


Today at 1500m, with high tire pressure and at 60-80kmh and 20Celcius ambient temperature I only read 72Celcius water temp and 91Celcius oil temp. It did feel pretty ok again as it should be!


So my questions here are:

HOW can altitude affect my setup? Can it be the reason of overheating?
If yes, what should I adjust or change on injection timing (I got the tool with me!) or fuel delivery?

The temperature always increases very slowy... it takes about 10minutes at 25-30Celcius ambient (thank god I never had more!) till the oil and water slowly increases to a point where I stop, open the hood and set idle at 2000RPM to get it cooling.
BUT the weird thing here is that it takes MINUTES to get the water temp down from 105Celcius to let's say 90! We are talking of 5minutes or more of fast idling with open hood!
If I pour 2 cups of water slowly in front of the radiator it cools inmediatly down to 80Celcius!
WHAT CONFUSES ME HERE IS: if I start to go downhill, let's say at 105Celcius water temp at same 2000RPM, the water temp gauge decreaes within 20-30seconds down to 90Celcius, within 1 minutes it's down to 80Celcius!!!
If I do the same but in fast idle it will take OVER 5 minutes to get down to 80!!!

So in other words, the little extra diesel it injects to reach 2000RPM is somehow enough to keep the system overheating!? How can that be??? Is it maybe really a bad injection timing or fuel amount???
I did this test now many times, but usually at 3000-5000m altitude.

Also, can it be that the Argentina Diesel with 46Cetane increases overheating? I bought some Cetane booster, no idea if it will help, but still need to try them.

What about Turbo aging, does a Turbo generate more heat into the oil when getting old?

I measured with an IR sensor at the entry of the radiator 88Celcius when it was at medium temperature idling at slow RPM. When I increased the IDLE to about 1500-2000RPM I saw the radiator inlet temp increase within about 1minute to 91Celcius! Is that normal??? I would think the higher RPM let's the fan turn faster and cool down more? Why does the water temp inlet increase instead of decreae?

I will get a heatsink oil cooler and check tomorrow for a very thin pusher fan in front of the radiator.
There is only very small space between AC cooler and front grill support!

BUT this are all band aids to a problem I didn't have 1 year ago! Why is it suddenly having so big problems?!


I am super happy for any ideas! I really fear to damage the engine and there are still quite some high passes in front of us going down to Patagonia!!

Thank you!

 

[GTSSportCoupe]

What a fascinating trip; sounds like a lot of fun.

Just a few thoughts reading through your overheating problems:

- The higher you are, the less efficient the cooling of your radiator because of less dense air. This might in part explain your altitude related problems.

- Also, water boils at a lower temperature at higher altitude. Not sure if this matters for a pressurized cooling system, but maybe something to consider.

- You might consider increasing the boost to 12-14psi, without increasing fuel. This will reduce AFR, thus reducing EGT. If your cooling system is operating on the edge, this will reduce chances of damage to the head from hot spots. Also, more air moving through the engine will help carry heat away.

- When the viscous fans are locked as you have done, there is a point where they loose efficiency moving air. They spin too fast and reach aerodynamic limits. So a properly setup viscous fan might actually be better at moving more air. I put 15,000cst oil in mine, and adjusted the thermal spring, and now it operates very well.

- IDI engines are more prone to absorbing heat in high load situations because of the pre-cup head design. This is why all Toyota's heavy duty turbo diesel engines are DI (direct injection), and IDI engines are non turbo. This is also why Toyota's only two IDI turbo diesels have over heating problems (2LTE and 1KZTE).

- I have a 2LTE, and tow a 1.5ton trailer in summer. My engine behaves very similar to what you have described, although I do not get hot enough to overflow the reservoir. I also find though that after cresting a long hill, the engine always cools faster if the vehicle is moving compared to idling. Just more efficient air movement. I have A/C condensor, transmission cooler, and intercooler all in front of the radiator also.

- I am going to install evans waterless coolant this winter. It does not boil until 180C, so protects from overheating, and hot-spots in the head (that lead to cracking). Other cruiser owners with turbo IDI engines have used this coolant with very good success. I don't know if it is appropriate for your situation though.

 

[Blade]

great infos, thank you very much!!!

I will try to get a ultra thin fan with the next visit, but this will take a few months from now! I want to find a quick solution. Looked at the junkyards and parts store today, but found nothing! I only have 3.5cm between AC radiator and grill support, so will need a very thin fan. I hope this makes the same effect as coasting down the hill = giving the extra air it needs.

Instead of increasing the boost can I decrease the fuel amount on the injection pump? I have more than enough power I think.. I never go over 550Celcius but could go up to 700Celcius (more power left but I don't use it due to EGT temperature)

What about removing the thermostat for a while? Will it improve the flow and the cooling?

 

[roscoFJ73]

I would get rid of the bug mesh. I dont think its a problem if the engine temp is under a 120c.
They all seem to drop temps real quick going downhill. I got my HZ75 to drop from 90c to 60c in 5 klms going down a long hill
There is not much fuel going into the engine and there is a good flow of air.

I dont think removing the t/stat will improve it. There is some restriction but I read somewhere that the restriction builds pressure on the pump side of the water pump.

You noticed how quick a cup of water cools it down. Some owners of 4x4 vehicles in competitions get a spare windscreen washer bottle and pump and set 2 squirters onto the radiator and give it a squirt when they see the temps climbing. Cools them down real quick.

Who did you buy the radiator from?

 

[Blade]

Ok, fixed the radiator.... it had a small hole on the bottom from rubbing on the AC cooler and it was leaking coolant. Probably happened during the 1000mile washboard trip we just did through the Salares near Salta, Argentina.
Going now on a 4800m pass, let's see how it performs. Going to remove the grill and see if I see a difference. It's removed in 2minutes.
I couldn't find a suitable fan in Salta but surely will be able to find a small 9" fan in Mendoza in about 2 weeks. It's a pusher that hopefully will help to get a "coasting" effect

My self made gauge showes 105-110Celcius but when I open the hood it's already smoking little bit out of the overflow tank at 4500meters. So not sure if that's due to the altitude or my gauge is little bit off or what.

I know ,I already thought a lot about the windscreen washer trick! But I fear of oxiding the stuff too much. I even have a 60liter Watertank in the front bumper, I would have enough water! But I want first try a waterless solution, if not I try it with the windscreen washer...

The radiator is from northern radiators in Australia. Broke open already in Mexico (bad welding), again in Costa Rica, again in Quito, then again in Peru (always on the bottom welding, the cut the bended edge too short I was told several times) and now in Argentina it was a rubbing problem, not the radiators fault. I am already a pro at removing and reinstalling that radiator!

 

[Blade]

drove yesterday from 3400m to 4200m in 2nd gear at 2500RPM, 550C EGT.
It was morning, so still cool at 10-15Celcius ambient temp.
Water went slowly up to about 100Celcius, Oil very slowly from 105 to 112Celcius.
When I shifted down to 1st gear the water temp went down within 1minute.
Coasting down the pass at 2000RPM it went down again from 100 to 90 in 20seconds (!!!) and in 40seconds coasting down from 100 to 80Celcius!

I still can't explain WHY coasting it cools down so fast! If I idle it at 2000RPM it would take 5x longer to cool down!
How can it be that the injection pump injects so much fuel into the engine at IDLE to make such a difference!

Also, I have a side pipe, stainless steel... over 100'000km old. Is it possible that it's clogged? Should I see if I can have it burned out?

 

[renago]

Sorry to,here these problems.
Normale motor 1HZ , never years in no circumstance.
If so there is a problem.
Running at 550C steady for some time , you are put the ciel ing of the pistons to great heat stress.
If this goes on , for some time , One day piston N. 1 will melt !
To my eye the problem is in the pump OR injectors.
This Needs to be care fully calibrated, and checked .
You should have Also the High altitude compensator that helps in your case.
But this devise is NOT easy to set.
You Need to find a good garage and make several trails.
IT could take you 1-2 weeks .

Good luck.

Renago

 

[renago]

just to recap on this issue .
My opinion is not that your car -truck is not cooling enough .
it is heating too much.
you are trying to solve the problems through the effect .
look for the cause , which is not in the cooling chain .
but in the unnecessary overheating under load.
the main parameter is EGT .
on a flat road , mid load , 100 kmh , mine is at 230 C .
120 kmh 350 C
altitude 500 mt .
diesel motors suffer a lot in high altitude , and heat up consequently.
but Toyota have developed the Altitude compensator that should solve this problem if correctly calibrated .

you must work on the pump and injectors , forget all other stuff .
I had a friend that found a good garage in Lima , she had the same problem as yours , over heating in altitude ,if possible i'll try to dig out the name or address .


bye Renago

 

[Blade]

on flat I have 300-400Celcius with no wind at 80kmh. When <2000meters the cooling system can take the heat, above 2000m it starts to get a problem, above 4000m it's really having big problems to keep the temperature low!

I have no altitude compensator, I have a TURBO compensator!

Injection pump was rebuilt 80'000km ago by Fred Holmes in Vancouver, got a new Denso housing and lots of new parts. Injectors I changed now in Quito (helped a lot to cool down!) and AGAIN in Cusco, Peru. So the injectors got about 10'000km on them, fairly new!
I didn't touch the pump since Vancouver, didn't change fuel screw etc. Not sure if that would help?

I read 550Celcius (BEFORE Turbo) is a very safe value! I read somewhere that with NO turbo the 1HZ gets to 700Celcius!?

 

[renago]

mine is turbo as well .
yours at 80 Kmh has EGT 300 C
mine at 100 kmh has 230 C .
What EGT you have at 100 kmh ?

the fact that you changed injectors and refreshed the Denso pump , dosen't mean that they are finely tuned !
I believe the cooling system of your car is doing a super work .
and is very , very efficient .
it simply should not work so hard ,
the engine should have more efficiency , burn all the diesel at the right moment .
and therefore heat less , a lot less.
As a matter of curiosity what king of mileage you get our from 1 L of diesel ?
I get at 100 kmh aprox 8 km per 1L .
if I go slower a bit better , 8,6 at the best .
never lower then 6 km/L
also this is an index of correct pump tuning .

i looked in different files , but couldn't find any garage name in Lima , sorry .

rgs Renago

 

[renago]

Diesel: right now 500ppm sulfur in Argentina and what I read about 46 Cetane.
in Europe we have 50-51 Cetane diesel.
this difference means you have more unburn diesel from your motor , because of the lower Cetane N.
on top of that when you are in altitude you also have far less oxygen , that worsen the situation.
to make the story short , you inject too much diesel for what your motor is capable to handle .
the result is that not all diesel fuel is detonating , some is still burning , and some is spit out , showing a nice black smoke .
all this is overheating the engine.
You need less fuel in the pump , and the temperatures will consequently drop.
if you move to a different area with better diesel or higher Cetane N , things will change .

rgs Renago

 

[Blade]

ok...will try and reduce the fuel screw a little bit to more lean... let's see how it works. Driving tomorrow from Mendoza to Santiago over a >4000m pass!

 

[renago]

pls let us know the difference in EGT temp .

hope this will help .

bye Renago

 

[Blade]

ok... removed the boost compensator hose. I guess this has the same effect, it injects less fuel right?
Difference on power and EGT was huge! WOT all the time uphill I could not get more than 550Celcius, no matter how steep, what gear or what RPM. I had much less power.
Going uphilll from 1500-3000m the water reached about 90Celcius... it did help A LITTLE BIT, but not the big breakthrough! I would guess it helped the water to be about 5Celcius cooler, not much more...

I bought now a 9" fan and will install it in front of the A/C radiator and see how much it helps to get some extra air...

By the way, on my offroad trip of around 1000km a few weeks ago with lots of 4WD drive, very low tire pressure, sandy parts, going often up to 5000m passes I had a fuel mileage of 17liter/100km, that is about 13.9miles per US gallon. Not great (had better mileage) but I guess ok for offroading at this altitudes?

 

[Blade]

ok... removed the boost compensator hose. I guess this has the same effect, it injects less fuel right?
Difference on power and EGT was huge! WOT all the time uphill I could not get more than 550Celcius, no matter how steep, what gear or what RPM. I had much less power.
Going uphilll from 1500-3000m the water reached about 90Celcius... it did help A LITTLE BIT, but not the big breakthrough! I would guess it helped the water to be about 5Celcius cooler, not much more...

I bought now a 9" fan and will install it in front of the A/C radiator and see how much it helps to get some extra air...

By the way, on my offroad trip of around 1000km a few weeks ago with lots of 4WD drive, very low tire pressure, sandy parts, going often up to 5000m passes I had a fuel mileage of 17liter/100km, that is about 13.9miles per US gallon. Not great (had better mileage) but I guess ok for offroading at this altitudes?

 

[renago]

Good to hear that you got some improvment.
Certainly the way to work is getting the carburation of fuel- air - altitude right for your car.
90 C on water is ok , I would not be too concerner about that.
Fuel mileage , in off road going at low speed -40-70 km/h , you should get at least 14 L x100 km.
If not , the carburation is waist too much fuel, and over heating.

550 C , is the top end of the stress curve for alluminim alloy pistons , over that you go into a permanent deformation .
Pls consider that you are talking the temperature NOT inside the combustione camera , but on through the exsaust gass.
WE must consider at least extra 50 C on top of that figure !
Going at 550 C for long time is putting the engin and particular the pistons at it's limit .
Pls be more gentil , on IT !!!
That engin has a very high compression ratio , 22 :1 , and IT was not made for turbo.
The turbo version has a compression of Only 18:1 !

My advise is to spend some time in fixing the pump and inectors to altitude and local Diesel fuel.
In the long run you will bene fit from IT.
EspeciallyIf you are overlanding for some time in S. America.

Have a good and safe run

Renago

 

[Blade]

thanks for the inputs!
Yep, will reduce the max. fuel screw to get lower EGT, but without boost compensator it felt like with no Turbo, had almost no power.

Most 1HZ overlanders I met had about 14-16liter average. Not really a very economic engine! Be aware that I had 3.8tons on this trip, 200liter of Diesel and 130liter of Water. It was 1 week of very remote area with no water or Diesel!
But wouldn't a lower cetane number also lower the mileage?

Question here is if an intercooler would help?! It would reduce the EGT (and I guess also water temp) BUT since I drive with one eye on the EGT I probably would go again back to 500Celcius and using just more power and I would have 0 win except more power? (don't need more power...it's ok, we are slow travelers anyway) Or would an intercooler bring a big help?

 

[renago]

Lower centale N will give lower power and more consumption.
Poor fuel is always a problem.

Ah intercooler could help , but ....
More complication to mitigate a problem that has not been addressed yet.
I personale will avoid IT.
You must work on the pump - injectors , forget the cooling system.

I have been traveling in similar situation and never got such egt temperature .
Fully loaded in the Sahara desert.
Drive looking ONLY on the EGT , all other temp water , oill will be simply a conseguence.

Hope you will find a good garage shortly.
Look where there are some mines , they have Diesel trucks and have found same problems as you.

Hope things get better.

Rgs Renago

 

[Diesel Cruiserman]

After reading through this thread I would throw out the intercooler number one and lowering the winch if not already done if I missed that point..

Had a couple kids from California years ago and built a fj40 with hardy ole 3B, they had heating issues in Mexico, turned out it was the winch blocking the air flow...?

Put a low boost turbo on a 1hz and had problems with high egts on most any climbs, then installed a water to air intercooler and it dropped the egts greatly, it however did not affect the water temp?

renago is more tech versed and seems to be more on the right track that I would follow.
Rob

 

[Blade]

EGT was always like that, also after the pump was freshly rebuilt in Canada by a well known Denso rebuilder in Vancouver... it would go up to 700Celcius if I would not lift up my foot to 500-550C. But oil temp (water temp I still had the idiot Toyota gauge so can't say how hot the water was) was up to Central America always below 100Celcius, now it goes to 110 or even more going on long uphills. I remember in Mexico we drove from 0m ocean straight to 4000m (was not smart we found out, we felt bad!) and the oil never went over 100Celcius.

The 1HZ engine is totally unknown in Argentina... the 1HD-T is known in 80series, but also very rare. Now I am a few days in Chile (Santiago area) and yet have not seen ANY Landcruiser at all!!! So I guess same problem... 1HZ is a very rare engine in latin america and 99% of the mechanics are useless and will destroy your car. That's why I do everything myself, even greasing the car or oil changes. I let no mechanic here touch my car.
Besides, I usually have 10x better tools than them. They only know the hammer as tool, trust me!

The injectors as said got 10'000km since they cleaned and readjusted them in Cusco, Peru. Although not sure if they did it right, I saw that they were using used shims out of a box full of shims from other cars/brands. I trusted it will be ok.
Pump I can decrease the fuel screw little bit to the lean side.

Winch I can't move lower or have to remove the complete front bumper. But bought now a 9" fan electrical pusher fan that can help push air that is lost through the winch...