radiator leak into crankcase

msjanket · Jul 24, 2011

I've got the Mitsubishi 3 cylinder K3a engine on my Iseki tractor. I have a pretty strong leak INTO the crankcase when I fill the radiator. Is this a cracked block, bad head gasket, bad water pump? The water level seems to fall below where the bottom of the head is. I'm guessing the engine on Mitsu tractor and an Iseki would be the same Mitsu and likely have a very similar water pump, head gasket, etc.

What are the choices for where this leak is originating?

thanks for your space over here,

the Iseki guy

Botetourt · Jul 24, 2011

I've got a similar 3 cyl in the S470D Buck, but not that familiar with any specific weak points of this engine like others on here will be. But it's not your water pump. It's either a cracked block, head gasket, or if there's water passages in the head, cracked head. Hope it's the the head gasket.

evan price · Jul 25, 2011

The water pump is belt-driven by the crankshaft. There is no inner connection to the engine other than via the coolant passages. If it is leaking like you say prepare for Very Bad Expensive Things. Need to pull the head and check the head gasket first (because it is the first thing removed) then get the head pressure checked. If that shows no leaking you are into the block.

Any competant automotive engine rebuilder or machine shop will be able to pressure test the head or block providing you bring it in to them. A crack that is just a crack will leak a lot more water than you might think, faster than you might think. If this tractor got stored with just water and no anti-freeze in the cooling system, might have freeze cracks in block & head.

Only good news is that K3x parts are somewhat common. I just saw a Cub Cadet with a K3G. They used the K3B in IHs and Masseys and Mitsu/Satohs. Toro mowers used K3Ds. There's plenty of other equipment including boats out there with the K3x motor. Almost as popular as Yanmars and Kubotas.

284 International · Jul 25, 2011

You may also have a bad freeze plug in the head.

lens12 · Jul 30, 2011

If it is leaking down to below the head gasket, it has to be a cracked block.

msjanket · Aug 7, 2011

The engine had a bad core plug. IT has 3 plugs top side of the head and the middle one was out completely. Took off the lifter shaft, hammered in a new plug, put it back together and all was well.

thanks for the interest