View Full Version : 430 Water In The Oil

Robert Wadman
05-10-2014, 08:32 PM
I have a 1959 Thunderbird Convertible. It is a 430 car, but was missing the 430 engine. I found a 1959 J code Hardtop that ran, but was very rusty and beat up. I'm attempting to use the 430 Hardtop engine in my J code convertible. When I got the engine running, I discovered water in the oil. I'm trying to determine what is wrong before I pull the engine. The previous owner advised me that he had hardened valve seats installed. Could this contribute to the problem? Any ideas or suggestions, will be greatly appreciated.

05-10-2014, 08:40 PM
Did you start with fresh oil and filter or did you use the oil that was already in the engine?

05-10-2014, 08:49 PM
Water in the oil can be from an intake manifold gasket that is improperly installed. It can also be from other problems (like a cracked head or blown head gasket).

In any event, DO NOT RUN YOUR ENGINE until the oil is clean. Water usually looks foamy on the dip stick (and everywhere else) and it will wipe out your bearings.

Drop the oil pan and clean the water out of everything. I would put fresh oil in, pull the distributor out and run the oil pump with a drill motor in reverse, just to get more water out. You only need a couple quarts of oil in the pan for this, then clean the pan again. - Dave

Robert Wadman
05-11-2014, 08:54 AM
When I bought the car I was told that the car had a rebuilt engine and the rebuild included hardening the valve seats. The car had been sitting for several years and was missing the battery. It was a reasonable price for 1959 430 Thunderbird, and as I mentioned my "J" code convertible needs a 430 motor. I checked the oil and it was clean and looked like it had just been changed. When I got it home, I disconnected the gas line and hooked up a small gas tank and battery. The 430 motor fired right up and sounded good. After letting it run a minute or so, I checked the oil and it was foaming and the dipstick registered above the full mark. I'm hoping it is not a cracked head or block. Again, any information or insight on this problem will be greatly appreciated.

05-11-2014, 09:43 AM
improper head gasket installation, improper intake manifold gasket, or a total lie given to you by the previous owner about it being rebuilt. He could have just changed the oil to hide the major problem...

05-11-2014, 09:49 AM
The best case scenario is that the heads or intake were not torqued correctly during the rebuild and water is seeping past the gaskets. Or as Dave mentioned they were installed incorrectly. The worst case is that there is a crack in the block that was not discovered before it was rebuilt. Or the car sat without anti-freeze in it and developed a crack. Either way you will have to take it apart to find out. Hopefully the fact that the oil was clean before you started it means it is only a gasket problem.


05-11-2014, 12:05 PM
There is also the possibility that the water entered thru the valley pan. There is a seal at the distributor housing and another seal at the stud for the distributor hold down, both known to be missing or deteriorated. If the engine was exposed to the elements before you got it or if there was/is a leak at the near by thermostat housing connection, that is most likely the way water got into your oil.

Robert Wadman
05-12-2014, 09:37 AM
Thanks for the insight regarding my problems with a 430 motor. I'm going to start by draining it and checking the gaskets. Hopefully, I can find the problem without having to see if the block is cracked. The car sat for several years before I tried to start it and I hoping that the manifold gaskets dried and failed. Thanks again for your ideas and recommendations. My "J" code car seems to be powered by "checkbook."

05-12-2014, 10:13 AM
I would focus on the valley pan first as mentioned above. A bad intake manifold gasket would only leak water to the valley pan.