The Stovebolt Site Forums The Shop Area Engine Shop 228 GMC water in oil

I bought a 1952 1/2 ton GMC earlier last spring that has a 228 in it. When I went to change the oil the first time I noticed a fair amount of water mixed with the oil. I suspected that I might have a problem, but the truck had sat outside for some time and I thought that rain water had possibly leaked into the engine through the cowl drain tube that is directly over the vent in the valve cover or condensation had accumulated in the block.
Well a couple a weeks ago, I started the rebuild of the truck and again found about a quart of coolant in the oil as I drained the pan. The truck had only been started a few times since I got it and not driven at all. It ran strong with no smoke or water vapor coming out the exhaust and no leaks of any kind. I am almost ready to pull the engine and have taken the head off, hoping I would find a blown head gasket. I did find some oil accumulated around the head gasket where the head bolts pass through the head but nothing that looked too alarming. There is also a braze repair that has been done to the rear stamped steel rocker arm support. The head has obviously been off and replaced. Looking at the cast numbers on it, it is a 228 head from 1950. I am not real familiar with GMC engines and am wondering if there are some vulnerable areas to be looking for? Once I have the engine out, I am planning on taking it to a rebuilder if I can find one in the Atlanta area that is good with these old GMC engines. It needs to vatted to clean it up and probably have it magnifluxed and all the bearings checked. Any suggested areas to look at or engine rebuilders?

Don't know anything about the quality of work they do, but here's one place to ask.
https://www.stovebolt.com/ubbthread...lat&Number=712751&gonew=1#UNREAD

Grigg
Thanks for the information. I will give him a call. I will also keep your engine/parts in mind depending on what I find and whether you still have them available.
Mike

Before you pull the head, it might be a good idea to pressure-check the cooling system. Since the old stovebolt radiators don't handle pressure much over 4 to 7 pounds without risking damage, I like to remove the hoses from the radiator, plug one and adapt a garden hose to the other one. Bypass the heater core by looping a piece of heater hose from one port to the other. You can presurize the block and head that way without risking radiator or heater damage. Once the pressure has been applied for a couple of minutes, spin the engine over with the spark plugs out to see if you've got a leaky head gasket or a cracked head. If water squirts out of one or more plug holes, you've found the leak. Water from the oil pan drain plug without leakage into the combustion chambers indicates a freeze crack into the crankcase. Be careful not to over-pressure the block with the hose, just turn the water supply valve on a little and maybe create a small leak with the block drain petcock to avoid getting full water line pressure on the castings.
Jerry

Thanks HotRod Lincoln for the tip. Unfortunately, I had already pulled the head and am now ready to pull the engine. I'll keep this in mind in case I encounter this again. Depending on the results of the magnifluxing I will probably be looking for a new head or engine. When I pulled the head I did not see any obvious place where water had been leaking along the head gasket, but I am not sure that you would.

Sometimes it's hard to spot a leak once things are apart. Be sure to check the block inside the crankcase for cracks, as the "freeze" plugs don't always push out if an engine gets frozen up with water in the block. Good luck!
Jerry