Water in oil/smoked for about 15 minutes, dis-asssembled
 

I thought I'd start a new post since the last post is so old.

I have an S5T2. It has about 2 hrs running time plus about 100 miles. My daughter over heated it but I'm not sure how long it was over heated.

The engine would smoke for about 15 minutes after initial start up. I did a coolant pressure test and found that there was a slow leak inside. After draining the oil I found out that there was water in the oil.

So, I pulled the engine and dis-assembled it.

After I dis-assembled the engine, I did not find any major problems. All of the hard parts were like new.

I did find one of the red coolant seals had fallen apart. It was not in one piece. The outside of the seal had separated from the red portion of the seal.
I don't know if that would be enough to allow water to seep into the oil.

I also found that in two different places the old style corner seal springs had not been removed when the new type corner seal springs were installed. Again, I don't know if that would be a problem.

One of the oil control rings wasn't pressed completely into the rotor but that might have just happened when I removed the rotor. Seems like the oil seals would press into place after torquing down the tension bolts.

I checked the irons to see if they were warped but all three irons check out OK.

If these things did not account for the water in the oil and the smoking for 15 minutes, I am open for suggestions.

At a minimum, I'd get the surfaces checked for flatness/warpage. You're going to need new coolant seals obviously. I'm no expert on the oil seal, but if it were mine, I'd get new oil control rings just to be safe.

Last time I built an engine, I used petroleum jelly on the coolant seals as the FSM recommended. I installed the seals, but didn't get a chance to finish assembling the engine, so the housing wasn't placed on the iron. I came back to it the next day to find the coolant seals were huge. The petroleum jelly swelled the seals up so much, they weren't useable anymore. I called Rx7world, since they were the closest to me, and he was able to hook me up with only the parts I needed.

I'm not saying that this is what happened to you, but I figured out the reason I got Hylomar in my Atkins rebuild kit, vs. a tub of petroleum jelly. Mazda FSM was wrong about that one :)