HJ45 1H engine assistance

[RocketCityCrzrs]

So I have an HJ45 from Costa Rica with the H diesel in it. Truck runs pretty good as far as I can tell but I just feel like something is not quite right with it and I thought you guys might be able to lend a collective hand.
The cooling system seems to blow all it's coolant out the overflow tank (over thw course of about 100 miles, not all at once). I was thinking maybe radiator cap, so I got a new one and put a new overflow on it because the old one was trash. Well now with fresh coolant in it, after running it for about 20 minutes the coolant went from nice green to pond water brown. I'm afraid that's a sign of head gasket woes.
The other oddity it has, is (as best as I can describe it) a Clacking sound at speed say 50mph. It doesn't sound like rod knock and it may just be how those old H motors sound.

Lastly, I think I'm in the market for a 2H for it. If anyone has one they want to offload, shoot me a pm. I don't mind one that needs a rebuild as I need to familiarize myself with them.

 

[roscoFJ73]

The coolant shouldn't have turned brown in 20 minutes even with a blown head gasket. My guess is the engine/radiator is full of corrosion. The boilover could be from a failed t/stat.

 

[RocketCityCrzrs]

The coolant shouldn't have turned brown in 20 minutes even with a blown head gasket. My guess is the engine/radiator is full of corrosion. The boilover could be from a failed t/stat.

So easy way to check the tstat is just remove it right? I don't have a housing gasket but I can RTV it to test it. As far as the corrosion, best to keep flushing the system or should I take the radiator to a shop and get cleaned?

 

[roscoFJ73]

There are ways of testing a t/stat by heating water in a saucepan and watching to see if it opens at the correct temperature.
I would cut a paper gasket using the old tap and tear method.
But I would tend to throw a new OEM one in and know its good. And you get the gasket with it.
The radiator needs to be pulled apart and have the cores rodded. The engine needs to be flushed clean.
But with the clacking noise and the age of the engine it might be easier/cheaper to look around for good 2H. Is it using oil?

 

[RocketCityCrzrs]

So engine doesn't appear to be using oil or have any water bleeding into the oil. I looked this morning and it doesn't even have a tstat in it so that isn't my problem...
I'm looking for a 2H actually

 

[RocketCityCrzrs]

Ok so update, I think it is the head gasket. Without a thermostat, the cooling system is building lots of pressure. Was driving it today and it started to run warmer than it should. I pulled over and it immediately started to cool down (still running). The overflow bottle looked like a kid with a straw blowing in milk and the upper rad hose was hard as a rock.

What say you!!????

 

[ceylonfj40nut]

@joekatana might have a 2H. Send him a PM. He is a great guy to work with. Recommend him highly.

 

[RocketCityCrzrs]

@joekatana might have a 2H. Send him a PM. He is a great guy to work with. Recommend him highly.

Hahahaha, he has one I already put a deposit on it.

I still wanna get the H going just for my benefit

 

[ceylonfj40nut]

I have a ton of H parts if you need anything. It came with a HJ45 I bought.

 

[RocketCityCrzrs]

Holy crap Batman!! Let me get this head off and see if it's ok, if not I'll buy that head off you