1hz Overheating (1 Viewer)

[ErfanFj45]

Hi everyone
It has been 2 years of running a 12v 1hz on my FJ45. Everything is OK until the summer comes and overheating problem begins.
I have checked all components of the cooling system.
The injection pump seems to work normally because no smoke comes out of the exhaust.(Just a little black smook sometimes.)
Overheating just happen when I'm driving in 35°C or above and at 80-90km/h with the 4th gear.
Something I should add is that I have removed the clutch fan and the fan works without clutch.
Any idea?

 

[ceylonfj40nut]

Engine pics pls. This will help troubleshoot. Do you have a fan shroud? Why did you remove the fan clutch? What radiator are you using?

 

[veiloctane]

thermostat closed?
have you pressure-checked the cooling system?

 

[roscoFJ73]

Overheating just happen when I'm driving in 35°C or above and at 80-90km/h with the 4th gear.

How do you know its overheating and what coolant temperatures is it reaching? If the fan shroud is missing, it must be reinstalled.

 

[ErfanFj45]

Engine pics pls. This will help troubleshoot. Do you have a fan shroud? Why did you remove the fan clutch? What radiator are you using?

I had a fan shroud but in this pics it is removed.
I removed the fan clutch because of the overheating but no difference I see. The radiator is Mercedes Benz 808's rad.

 

[ErfanFj45]

thermostat closed?
have you pressure-checked the cooling system?

I guess the pressure is not OK because when it is overheated, the hoses are soft.

 

[ceylonfj40nut]

I guess the pressure is not OK because when it is overheated, the hoses are soft.

Put the shroud on!

 

[ErfanFj45]

How do you know its overheating and what coolant temperatures is it reaching? If the fan shroud is missing, it must be reinstalled.

Put the shroud on!

It is always on don't worry

 

[ErfanFj45]

How do you know its overheating and what coolant temperatures is it reaching? If the fan shroud is missing, it must be reinstalled.

The degree goes on the third line.Actually I don't have digital temprature gauge so idk the exact temp.

 

[veiloctane]

I guess the pressure is not OK because when it is overheated, the hoses are soft.

Pull the thermostat out and test it sounds like it could be stuck closed.

 

[ErfanFj45]

Pull the thermostat out and test it sounds like it could be stuck closed.

I removed it for a few days to check if it would be better or not but I forgot to check the hoses.No changes at all.

 

[veiloctane]

I wouldn’t be surprised it were as simple as a radiator cap or you have a air bubble in it.

You sure your temp gauge/ or sensor probe is accurate?

 

[ErfanFj45]

I wouldn’t be surprised it were as simple as a radiator cap or you have a air bubble in it.

You sure your temp gauge/ or sensor probe is accurate?

Bubble? What's that
I'll use to use this temp gauge on my 2f. It always was stopping in the middle on the first line.

 

[veiloctane]

Bubble? What's that
I'll use to use this temp gauge on my 2f. It always was stopping in the middle on the first line.

You may need to bleed you cooling system to get rid of air pockets or bubbles in the cooling system.

 

[roscoFJ73]

The degree goes on the third line

Which is pretty normal for a 1HZ on a warm day. I would get a proper gauge if you are worried, but all my 1HZ have hovered around there on 35c days.

 

[ErfanFj45]

Which is pretty normal for a 1HZ on a warm day.

My thermostat opens at 76°C. Is the third line on my FJ45's gauge equals to something around 85-90°C?
I'm asking this because I guess it is the suitable temp for the engine. If you have exact information, I'm willing to know.

 

[veiloctane]

Thread '1HZ (diesel) coolant temperatures?'
1HZ (diesel) coolant temperatures? - https://forum.ih8mud.com/threads/1hz-diesel-coolant-temperatures.1210911/

 

[roscoFJ73]

My thermostat opens at 76°C. Is the third line on my FJ45's gauge equals to something around 85-90°C?
I'm asking this because I guess it is the suitable temp for the engine. If you have exact information, I'm willing to know.

80c to 100c is well within the operating temp for a 1HZ. You need something like an ENGINE WATCHDOG or its competitor. You will find that in summer, a 1HZ is above 90c nearly all the time.

 

[mudgudgeon]

Is the third line on my FJ45's gauge equals to something around 85-90°C?

Not necessarily. Factory gauges aren't that accurate.
If you want to be sure what your factory gauges is reading, you need to verify what temperature you actually have with an aftermarket gauge. Can be temporary or permanent.
You could also use an infrared heat test gun to take a temperature reading on the thermostat housing

 

[mudgudgeon]

My thermostat opens at 76°C

Did you test it by boiling it?

It should start to open about then, and should be fully open at around 85⁰C

Boil it and watch it to make sure it opens fully