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Hi All --- First post with a new car, 1938 1603 Sedan. I bought the car with a blown headgasket and am in the process of replacing that. So far the block does not appear to be cracked.

I've heard that the oil coolers were a problem, but I've also heard that this applies mostly to the 1934 models. By 1938 they were pretty robust. Do you guys agree?

The previous owner of my car found coolant in the oil when he changed it prior to my ownership. I figure that was probably due to the bad head gasket, but it makes me wonder about the oil cooler.

Should I by-pass the cooler as a matter of course? Is it necessary? Because they run in series, a friend with a 1934 bypassed the oil filter and the cooler by blocking off their ports at the engine base. I could do that, I suppose. Would there be any harm in doing that? Aside from not having an oil filter?

Thanks ---
Scott

You can pressure test it by making up a plate and using a simple blow gun and a regulated air supply. Submerge the unit in a bucket of water. Do not exceed 60 psi, although the thing will probably handle up to 100 psi. A good machine shop could do this if you don't have a compressor.

Another test would be to just bypass the thing and see if coolant shows up in the oil.

If the motor is worn and using non-detergent oil, water will collect in the bottom of the oil pan from condensation. If the motor is using detergent oil it should be emulsified (turned into gunk) if coolant is leaking.

Except for 1934 as noted, the oil cooler cores are very robust and almost never cause problems. If it does, you can make a shunt within the housing to continue the flow, but you can't just block it off or you will starve the engine for lubrication.

Since you have a non-pressure cooling system, if it does fail, you may find a hint of coolant in the oil, what you will find is A LOT of oil in the coolant as the oil pressures are of course higher than the coolant pressure (which is essentially zero).

G'day scott12180,
to PackardInfo, and I invite you to include your '38 1603 Sedan in the Packard Owner's Registry.