BJ74 consuming coolant (1 Viewer)

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Feb 23, 2017
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Location
Squamish, B.C.
I'm wondering about coolant loss in my BJ74.

As a bit of background, it is a bit worn and rusty, with 286xxx kms.

When I brought it to EBI for an inspection before I bought it the coolant was low, it took a litre, and the mechanic said to not worry at all about it needing a litre of coolant. That was in March of 2017. Now the coolant is once again so low that I can't see it when I open the pressure cap. No signs of milkiness on the oil dipstick, no foam under the oil cap, no drips of coolant on the ground. The truck seems to run just fine, I've had a couple unrelated things fixed (muffler, exhaust manifold).

So where is the coolant going? Is it normal for BJ74s to just consume it slowly?

Hoping very much that it isn't a head gasket.

Thanks!
Al
 
Al, pm me a contact number. I've got a combustion leak tester you can borrow. Got the same issue as well that I haven't chased down yet.

I'm just up the road...
 
How does that combustion leak tester work?
 
Leaking Head gasket. I've had to replace the head gasket on 50% of my BJ74's. The other 50%, I have not driven, so they probably need to be done too.

Note that combustion leak detectors are designed to work on small block chevy's that leak like (insert name of something that is known to be really leaky) and leaks can be detected at idle or by revving the engine in a garage. To detect a leak on a 13B-T, you need to get the engine under full power at high revs. Either do the leak detection on a chassis dyno (unlikely), or on the street.

I once took a 3B-T to an well regarded engine rebuilding shop to check for combustion leaks, and got a negative test result, even though it really was a leaky head gasket after all.

The telltale is bubbling out the rad overflow bottle after a hard drive, possibly overflowing it. I once bought a BJ74 with low coolant, topped it up, drive around town for a year without a problem, but as soon as I hit the highway, it was immediately overflowing the rad overflow bottle.
 
Ok, I have never noticed any bubbling in the rad overflow, that said I don't check it after every drive. What would classify as a hard drive? Also just so you know what kind of quantities we are talking about here, it lost about a litre of coolant since March of this year, approx 12000km of driving.

On your bj74s that had leaky head gaskets was there signs of coolant in the oil? Or did they leak directly into the combustion chamber?

Thanks
 
Leaking Head gasket. I've had to replace the head gasket on 50% of my BJ74's. The other 50%, I have not driven, so they probably need to be done too.

Note that combustion leak detectors are designed to work on small block chevy's that leak like (insert name of something that is known to be really leaky) and leaks can be detected at idle or by revving the engine in a garage. To detect a leak on a 13B-T, you need to get the engine under full power at high revs. Either do the leak detection on a chassis dyno (unlikely), or on the street.

I once took a 3B-T to an well regarded engine rebuilding shop to check for combustion leaks, and got a negative test result, even though it really was a leaky head gasket after all.

The telltale is bubbling out the rad overflow bottle after a hard drive, possibly overflowing it. I once bought a BJ74 with low coolant, topped it up, drive around town for a year without a problem, but as soon as I hit the highway, it was immediately overflowing the rad overflow bottle.


Had similar issue with mine after I bought it, with cracked head in all 4 chambers, no issue around town and no sign of water in the oil, but was coming out the over flow when I drove it on the highway. It was explained to me that the compression will pressurise the cooling system which causes the water to come out of the over flow and not go into the oil.
 
Hey look at all these western Canadians, I hope to soon be joining y'all in the Land Cruiser club.
 
So where is the coolant going? Is it normal for BJ74s to just consume it slowly?

A landcruiser should go for a few years without a top up. I don't know what you have done so far but the 1st thing is to get a new radiator cap .
The next thing is to check all the hose clamps.
The hoses should get hard at operating temp.
 
Did the 13BT's come stock with a fibre or MLS head gasket? I'm guessing fibre? Can you up grade to an MLS on them?
 
Well I found some coolant on the side of the engine block, on the intake side (left, passenger as it's an RHD). It is very difficult to see but the dark area in the lower right of my photo is wet with coolant, I'm sure it's not oil because of the colour (can't tell in the photo though). Is there a coolant inlet/outlet above this area? I'm hoping it's that and not the head gasket. Unfortunately this part of the head and block is very tough to see due to the turbo and all that other stuff.

Engine runs great and has plenty of power, and it doesn't overheat. Not actively leaking out when parked, so it must need the pressure of operating temps to leak.

20171111_141627.jpg
 
More photos, there is a tube that goes from below the rad cap around the left side of the engine and out of sight to directly where the leak seems to be, indicated with red in the first photo.

In the second photo you can see the part on the left side of the block that says 13B has coolant on it, but there is also coolant above the head gasket (head gasket marked in red, I think, coolant above marked in green.)

This makes me think that the other connection of the tube I first mentioned is leaking, only while the vehicle is running, and the leak is out of sight under the intake (I think it's the intake). The coolant visible on the block is from the end of the tube.

Does that make sense? I am really hoping coolant isn't leaking right onto the block from the head gasket, I have been told this is rare and I don't think it is.

Does anyone know what that tube that goes from under the rad cap around the left side of the engine is? How do I access it?

Thanks!

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I can tell from the pics your coolant system needs a lot of work. You shouldnt have those big coolant/corrosion boogers climbing out from hoses etc.
The only way to fix this is to pull off every rubber hose and clean the metal surface it plugs onto. Check the hoses carefully for cracks and splits. Clamps are cheap, so I would be replacing them. I would replace the hoses also unless they look brand new.

Step 2 is to get rid of that green coolant by flushing the engine and radiator several times and replace it with Toyota Red coolant.
This is why I suggested the checking the easy things first. Head gaskets etc are last on the list unless you have firm evidence that's the problem.
As its not overheating or doing anything weird you can probably consider yourself lucky(if you fix it all soon).
 
from my 2lt experience i can tell you I found nasty corrosion cavities in the aluminum housings, under the ends of the hoses, either at the coolant outing of timing plate or at the thermostat housing.
And my hose connections were clean.

I flushed the system many times with distilled water and ran the engine in between , then toyota red.
surely other engine coolants have the same properties, but I don't think its worth the risk to experiment with other stuff.

there should be a block drain plug on the engine side, could not open that on mine, so had to do more work.
 

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