Landruiser HJ60 Diesel overheating in hot summers of 45C (113F) (1 Viewer)

[naveedmerchant]

I have heating issues with my Landcruiser HJ60 1986 with 2H diesel engine and noticed this as I entered the hot weather territory while long hours driving with speed ranging from 80 to 110km/hr (50 to 70 mph) and weather temperatures ranging from 45C to 48C (113F to 119F) with temperature gauge reached to the very top in white zone but when I switched off AC the temperature dropped by another say 10% . Whenever engine would overheat I stopped for number of intervals and when opened radiator cap there was a lot of hot gas and also noted some rusty water color and after some rest of 5 to 10 minutes poured water in raditor on engine idling mode but only a small quantity of water went in. On several occasions I used to also pour water on the exterior top of radiator on engine start that way the temperature gauge would come down drastically but again gradually started to rise during the hot weather travel. The overheating frequency would get higher when climbing the hill. At times noticed spikes on the gauge ranging from levels 75% to 95% within the white temperature level. Also noticed there was so much pressure in radiator there was water flowing out from the radiator to the coolant box , I have new original radiator cap. On the next day morning I had to pour almost 2 liters of water in radiator.

However as I entered into the cooler weather in 85sC while the temperature became normal at 50% level even with AC on and got no heating issues.

Would someone please let me know how can I resolve this.

 

[Benjaman]

If you've got rust colored water? You may need to have the rad rodded out. Or you may just need some fresh coolant.

Also, you really dont need to remove the rad cap and add cold water, as thats a good way to warp/crack stuff. Let the engine cool for 25~30 minutes before shocking it with cold water.

I'm also not clear on the stock gauge. If it's not in the red, it may not be overheating.

 

[naveedmerchant]

If you've got rust colored water? You may need to have the rad rodded out. Or you may just need some fresh coolant.

Also, you really dont need to remove the rad cap and add cold water, as thats a good way to warp/crack stuff. Let the engine cool for 25~30 minutes before shocking it with cold water.

I'm also not clear on the stock gauge. If it's not in the red, it may not be overheating.

I used technique of removing hot gas from radiator by turning slightly back and firth under pressure by hand and then gradually letting gas out and then pour water slowly after starting engine . The guage was just sightly below red and engine get a changed sound when it gets hot so it was still in somewhat drivable zone with a very hot engine

 

[In2cruisers]

How's the fan clutch?

 

[naveedmerchant]

How's the fan clutch?

I had replaced fan clutch with genuine new toyota few months back and assum that might be OK. I will again recheck

 

[ashack2004]

Over heating

Sorry to hear about your over heating issues naveedmerchant. There are couple question I have for you on this.
1. Do you have any coolant in your oil? Keep in mind that your coolant system are a sealed system in which coolant should not be disappearing unless it is getting pushed out the system through the overflow, leaking somewhere and or going to the crankcase with your oil. If you do have coolant in your oil you could have a bad head gasket and or a crack somewhere that could be allowing coolant to pass into the crank case. With a blown head gasket under certain circumstances the engine could build high pressures in your radiator making the over flow seem like the engine is overheating and push all your coolant out.
2. Testing the Radiator:
a. Throughout the 300,000 miles you get on your Toyota there will be a lot of heating up and cooling down. Putting stress over time on your coolant system and causing issues with the thermostat, water pump and radiator. The best way I have found to test the radiator is this. Crank the vehicle up and let it warm up to temp and then turn the vehicle off. Take your hand and very carefully feel around on the rods (in front of the Fan) of the radiator. Starting at the top and working your way down to the bottom. Keeping in mind that water is pump and circulated through the radiator. When I found out mine was bad I would be able to touch the top of the radiator and it would be hot and when I would make my way down I could feel that the radiator was not even warm but cold. This was telling me that the Rods in the Radiator like Benjaman stated could be clogged which was not allowing coolant to flow and the Radiator might need to be roded out. A good 100 bucks at a local Radiator shop should fix this. Nothing else the best price I could find a new Radiator was on Rockauto.com
b. More Information for SPECTRA PREMIUM CU12
With that there is not that much more than can cause you have issues, unless your fan is not working but you stated you have already replaced. I would start with some of these tests and see where that leads. Good Luck!

 

[Tapage]

Been a long term 2H owner I could tell 2H it's not that good in that cooling head part .. so if you are pushing it hard ( I mean high EGT's ) yo will see temp raising .. even first than EGT's going nuts ..

So I would start with the basics about cooling system, cap, rad and cooland .. ( cooling system flush ) then will move to fan clutch and so on ..

Comp number also have play ..

 

[darthvincor]

In my experience, even under difficult circumstances, an HJ60 can keep cool.
My HJ60 towed its own weight on a 40C day on hilly terrain.
Drove normally on 45C days.
And that was with old coolant, and at least 2 external leaks.
And even has an auto, which taxes the cooling system even more.
Yet it never went over the halfway point, on the gauge.

I think they should be able to run fine under all circumstances, if properly maintained and not modified.

 

[naveedmerchant]

Thank you so much... I will start working on this tomorrow

 

[naveedmerchant]

Sorry to hear about your over heating issues naveedmerchant. There are couple question I have for you on this.
1. Do you have any coolant in your oil? Keep in mind that your coolant system are a sealed system in which coolant should not be disappearing unless it is getting pushed out the system through the overflow, leaking somewhere and or going to the crankcase with your oil. If you do have coolant in your oil you could have a bad head gasket and or a crack somewhere that could be allowing coolant to pass into the crank case. With a blown head gasket under certain circumstances the engine could build high pressures in your radiator making the over flow seem like the engine is overheating and push all your coolant out.
2. Testing the Radiator:
a. Throughout the 300,000 miles you get on your Toyota there will be a lot of heating up and cooling down. Putting stress over time on your coolant system and causing issues with the thermostat, water pump and radiator. The best way I have found to test the radiator is this. Crank the vehicle up and let it warm up to temp and then turn the vehicle off. Take your hand and very carefully feel around on the rods (in front of the Fan) of the radiator. Starting at the top and working your way down to the bottom. Keeping in mind that water is pump and circulated through the radiator. When I found out mine was bad I would be able to touch the top of the radiator and it would be hot and when I would make my way down I could feel that the radiator was not even warm but cold. This was telling me that the Rods in the Radiator like Benjaman stated could be clogged which was not allowing coolant to flow and the Radiator might need to be roded out. A good 100 bucks at a local Radiator shop should fix this. Nothing else the best price I could find a new Radiator was on Rockauto.com
b. More Information for SPECTRA PREMIUM CU12
With that there is not that much more than can cause you have issues, unless your fan is not working but you stated you have already replaced. I would start with some of these tests and see where that leads. Good Luck!

Thanks ... have started working on the checklisted items...

Will this radiator at More Information for SPECTRA PREMIUM CU12 work with 2H deisel engine 1986 HJ60? how many core is it? I wanted 4 core ideally in aluminum

 

[naveedmerchant]

Been a long term 2H owner I could tell 2H it's not that good in that cooling head part .. so if you are pushing it hard ( I mean high EGT's ) yo will see temp raising .. even first than EGT's going nuts ..

So I would start with the basics about cooling system, cap, rad and cooland .. ( cooling system flush ) then will move to fan clutch and so on ..

Comp number also have play ..

What is Comp number?

 

[Tapage]

What is Comp number?

compression numbers by cylinder ..

 

[naveedmerchant]

Your assessments were correct.. the 4 core radiator was blocked and got this cleaned....

Also came to know that the clutch fan has been made direct from the engine.. Assume this should be OK?

 

[Tapage]

Also came to know that the clutch fan has been made direct from the engine.. Assume this should be OK?

should not .. that's why you have " fan clutch " there after all ..

 

[naveedmerchant]

I got the radiator rodded out and cleaned out the condenser ... did a test drive at 95 to 100 km/hr (55 to 68 miles/hr) in approx 42C+ (107F+) and noted temperature started going up by more than 50%... I am assuming if i drive in 45C+ (113F+) environment its engine likely to heat up

The thermostat is not present so assume that should be ok i guess and the clutch fan is direct

I recently overhauled my engine few months.

I probably need to go through a set of checklist again carefully incase if i have missed anything out...

1. To look for gaps in fan shroud and seal it if any found

2. To check the fuel system on over fuelling and whether its is running lean. Need to show this a good diesel fuel system specialist

3. Will do a CO test,. i am guessing my head gasket is fine otherwise it would still heat at any temperature environment?

4. Need advice what type of coolant shall i put and what is the right mixing ratio?

5. Was told by a friend of mine to shift AC condenser from the front to someother place within the undercarriage cavity as it blocks the radiator. I think my condeser isnt original and dont know if its blocking radiator. Is this shifting of condenser workable?

6. Do i need to check compression numbers by cylinder ?

Is there anything else that i should add to the list?

 

[Elbert]

The A/C condensor has to be in the air flow of the vehicle and requires air to flow through it even if the truck is not moving(while A/C is operational)...which means it requires a fan. A/C condensers are made to mount in front of the radiator for this very reason. Its unlikely that an alternative mounting point is available that would permit the proper air flow and also you would have to install an electric fan to move air across the condenser. All of which is not worth screwing with. If the condenser is clean...its not part of your cooling issue.

You should install an aftermarket gauge to determine the actual temps your engine is running. IF the radiator is not boiling over have you determined if you factory gauge is working right?

I hope you are not running 100% water in your cooling system...if so you will have some serious issues with rust. You should drain the entire cooling system, refill with a 50/50 mix of green coolant to water (use distilled water if available).

Did these issues start after your "overhaul"....if so then that's most likely a good clue that something was done improper or you may have a part failure. If you overhauled the engine I assume you installed a new water pump?

You should check compression in every cylinder.

Radiator cap would be good to replace if never replaced.

Post up pics of the engine, showing the fan setup, fan shroud...etc.

You should install a new thermostat with proper gaskets and seals that apply to your specific engine.

 

[rustybucket]

as a former, and now part time mechanic this is what I would have done

Fist off, after the engine was cooled down, I would have checked for any external leaks and repaired those. Next would have put on my coolant pressure tester and put 15 bls of pressure on cap, to see what the release pressure was. Its stamped or imprinted on the cap. Next would be to pressure test the cooling system and leave 15 bls of pressure on it. The needle should not move. If it moved say a pound and stabilizes then its good cold. Try it again after the engine is heated. This is the most likely time the head gasket gap leakage would be at its greatest.

I cannot say for sure in a diesel, but in a gas engine, combustion pressures of 1,000 psi are going to force the gasses into the cooling system. You will either loose coolant, or over pressurize the coolant and force antifreeze out the overflow tube.

One of the clues to a leaking head gasket is taking off the catalytic converter. If its white coating on the grey monolith structure, you have a head gasket failure and or warped head, valve saddle cracked. You can also take the car into a shop that had a 5 gas analyser and have the mechanic use it to sniff Co2 at the neck of the radiator to confirm a blow head gasket. Another way is Chemical analyzer, which I used to verify coolant dealing integrity.

Do you know the history of this engine and when it was last flushed? Technically, if it was last flushed two years ago, and you have rust in the antifreeze, then you have a possible bad engine to frame ground or missing ground. Do your self a favor, take a multi meter, put one prove in the antifreeze and one on the negative terminal of the battery. If you see a potential, then you have ground issues.

If the coolant clutch is good and no cold spots on radiator "check with hand" do a flow test on the heater core hose. Not sure if the water pump impellers in these trucks can come loose, but the flow test will reveal the loose impeller if this is the case.

Coolant should be 50/50 ethylene glycol to water or, what ever factory specs state.