LJ70 2.4 Overheating

[Cardo]

Ere we go. Radiator seam on the top tank of the radiator split and had to limp home topping it up every so many miles once it had cooled down enough. Had the Rad welded up and checked and made sure pipes are all clipped up nice and tight but still the temp climbs up when the engine has to work like going up a hill. On the flat or down hill it cools down but, the minute I start to go up a hill the temp climbs. The radiator cap could do with replacing if I can find one on island but is there anything else it could be. The engine seems to be running ok and I haven't found any water on the dipstick when checking the oil. Any ideas would be much appreciated.

 

[Beau]

I would be checking the entire coolant system if I was you. I've not known of a radiator just splitting like that, is it possible your system is getting higher pressure than it should and the rad cap isn't bleeding the pressure to the overflow tank?

I'd also make sure that your radiator is clean on both sides. If you have a AC condenser it's common for muck to build up in between over time and prevent much needed airflow.

Depending on age, the thermostat is worth a check, as well as the water pump.

 

[Cardo]

Thanks for the reply Beau. It wouldn't be the AC condenser as I don't have AC on my model, but I will check the thermostat.Is there a way of checking it other than replacing it with a new one. I see you are in Guyana so probably have the same problems of importing as we do here in Grenada. I think the water pump is ok but I will double check it. Thanks for your input.

 

[Crushers]

if you split the rad then you have an issue that had been there before the rad cracked.
pull the head and you will find cracks between the valves.
typical issue with the dreaded 2LT engines.

 

[Beau]

Thanks for the reply Beau. It wouldn't be the AC condenser as I don't have AC on my model, but I will check the thermostat.Is there a way of checking it other than replacing it with a new one. I see you are in Guyana so probably have the same problems of importing as we do here in Grenada. I think the water pump is ok but I will double check it. Thanks for your input.

You can remove and check the thermostat is operating as it should in hot water, monitoring the water temp. I'm actually located in Florida, US. Parts are harder to find down that end but a few companies do export as well

 

[Cardo]

OK I have had the radiator rebuilt and checked the thermostat which I think needs changing as it only opened when the water was boiling. The guy who rebuilt my radiator thinks that the fan is not working properly as it spins when the engine is on but can be stopped just by grabbing hold of it. ( This is Grenada) Is there a way of checking this and if it is bust can it be repaired? Thanks for all your advice guys as I am a bit out on a limb here and have to try and fix stuff myself if I can.

 

[Shayne]

If the thermostat is set to open at 70 degrees that's how hot your engine will get before the heated coolant is replaced with the cold stuff in the rad , this will be the same if the stat doesn't open until coolant reaches 90 degrees or 100 ,if you have doubts get a new one .

The viscous fan can be split drained and re-oiled , 60ml of 10,000 cst silicone oil is the only specific suggestion for how much of what to use i have ever come across .

 

[Cardo]

Cheers Shayne. Is it a difficult job to re oil the fan or something that I could probably manage?

 

[Shayne]

I bought the oil to do mine but never got around to it to be honest . I imagine getting it off is the hardest part , pics and vids found on google suggest to me that oil is the only moving part inside but hopefully someone that has done it will be along to advise .

I think a dodgy stat might explain your split rad as well .

 

[Shayne]

 

[alexy]

if you have silicone oil, do not fear to open it and refill it.
I did it this summer and its easier than you'd think.

first, pay attention how long time you hear the fan engaged after a cold start. if its very short time that could suggest you lost some oil.

taking it from the engine is easy, 4 screws.
then, place the fan clutch on a table and tap the screws with a good quality screwdriver, maybe put some spray to loose them, leave overnight.
once you are ready to open the screws, you must take care not to strip the screws thread. I basically leant over the screwdriver with good weight and they opened no problem. some people say to use an impact screwdriver, I just used quality tools.

try to drain the oil, so you have a reference on how much was left.

from here , you can alter two things
1-the temperature the valves open, from those screws on the lid. mind you this will engage the fan earlier, you will hear more roaring and your fuel consumption will rise. I had 8.3/100km highway, now Im at 9/100
2-adding silicone oil. cannot remember how much I put.

when you put it back be careful not to pinch the rubber seal.
search ih8mud on the 70 section for more info.

Make sure the rad cap does open at the pressure and check if you do not have air bubbles in the coolant once the engine runs.

hope this helps.

 

[Cardo]

Alexy and Shayne thank you so much for the info. Gives me confidence to do it. I will see if I can find some silicon oil on the island. There are a few places that should have it. Once again many thanks!

 

[Mauro M]

Hello,
I would suggest also to look for water pressure, maybe the water pump is failed.

 

[Cardo]

Thanks MauroM. I will check that also.

 

[alexy]

the silicone oil is used for gearboxes in small model cars. I bought mine from a hobby shop, not from Toyota.

 

[Cardo]

Cheers for that tip Alexy. I have located a source on the island so will look at it in a few days.