Oil getting into radiator

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Joined
Oct 4, 2014
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Location
Minnesota, USA
My Car
1972 H code fastback Boss 351 clone
Hey guys, a little insight needed. I was checking coolant last night and found an oily sludge in my radiator, it was building up on my radiator cap seal, and I can see it building up on the ends of the radiator cross passages. How can I tell if this is engine oil or a leaking internal trans cooler? Its just a brownish/black sludge. A couple notes: I did not re-torque head gaskets, Fel-Pro told me not to with their Perma-seal head gaskets, and also I have a stock brass/copper radiator, not sure of its age but it does not leak externally and it keeps the engine cool. I'm leaning toward a leaking head gasket as I feel I should have re-torqued gaskets.

 
Check all your fluids. Coolant destroys bearings. If your transmission is clear and the oil is good, I'd do a very thorough flush of the system and use a good block seal product like one of the K&W products as a first step in trying to resolve this issue. If that fails, I would personally pull the engine and go through it as it might be a crack in the water jacket and catching early will keep from destroying things like cranks and rods etc.

 
How long since you did your rebuild? I have seen residue from having the block and heads boiled do this as well. Some machine shops use a mild caustic to clean the block. Most head gasket leaks that severe would also cause the engine to come to temperature very quickly or even over heat.

Don

 
Check all your fluids. Coolant destroys bearings. If your transmission is clear and the oil is good, I'd do a very thorough flush of the system and use a good block seal product like one of the K&W products as a first step in trying to resolve this issue. If that fails, I would personally pull the engine and go through it as it might be a crack in the water jacket and catching early will keep from destroying things like cranks and rods etc.
^^^this first of all, also how is the engines oil, any sign of moisture no matter how slight as this may constitute a porous bore (have come across this more than once) Another thing I have personally come across if no moisture in the oil, has been a fault in an oil gallery (not a Cleveland though) as it would have been ever so slight as no water could come into oil but, oil was going into the radiator. It was a real head scratcher, pulled it all back down and went through everything, yet could find no reason why. So assembled the engine again and the exact same problem. The engine ran fine, no overheating, good oil pressure, so pulled it out yet again and pulled it down again but, this time got the block tested. They checked the water passages (as we did) under pressure and all was fine, it was only when they pressure tested the oil galleries did it become apparent but, not straight away. When they first started testing everything was fine, it was only once they got heat into it did the problem rear its ugly head. They said that the pressure was only dropping ever so slightly and they rechecked to make sure everything was hooked up properly, which it was, so they thought they'd do the test again the next morning just in case something was slightly not set up properly. So they did the test again the next day and it did the exact same thing, unbelievable as no one had ever seen or heard of anything so crazy, especially considering there was no water in the oil.

When it comes to engines some crazy things can happen and most of which I've come across, including one of my very own engines.

 
I checked the oil and trans fluid, neither have any signs of moisture, I think I found the issue. The passenger side head gasket, where you can see the edge of the head/block mating area, the gasket is oil colored and there is a small run of oil on the block. I'm pretty sure its because I did not re-torque the gaskets per Fel-Pros instructions. My builder also says SB Fords can be prone to head gasket leaks as they don't have as many head bolts as other engines. Thankfully I'm in the middle of building my other Cleveland, so I will disassemble this engine, replace gaskets, and tuck it away for the future. Thanks Gents!!

 
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