7.3L Powerstroke Coolant in the Oil

This 7.3 engine has an odd crack and, as a result, you could literally pour coolant in at the top and it goes through the motor and out into the oil drain pan. Usually this problem is the result of a front cover issue where cavitation occurs between the water pump and the aluminum front cover. However, this front cover looked just fine. This engine has been in other shops before and the front cover has been resealed twice. It is not a small feat to change out one of these front covers.

When we got the engine out and on the stand, we pressurized it and found coolant dripping out of the bottom of the bore at the #6 cylinder. At this point, we have to disassemble this engine and see if the crack is in the cylinder head or if it is in the block itself.

This engine has been cared for, the oil has been changed and the injectors were all good working sets. It just has this funny little coolant problem. Also, it is obvious that this is not the original engine. This is a stick shift truck and a stick shift block has short pins in the back but if you look here you can tell that someone actually cut these pins to put this thing in. We don’t even know how many miles are on this engine or what year it is. You can change the front cover so it might be an early 90s block and head that were prone to having this problem. This is a 2000 model truck. You just don’t see this problem in a 1999 and up Powerstroke. Some of the early Powerstrokes, the old body style trucks you would see this because the casts were a little thinner.

With the cylinder head off, we saw no head gasket problems. However, when we pulled the piston out, we saw that there has obviously been water in this cylinder resulting in a pin hole in the bore. This is not common in a 7.3 Powerstroke. A lot of the older IDI engines will get a pin hole in the casting and there is nothing you can do about it. This block isn’t trashed; the bore can be sleeved. However, we have another block in very good condition that somebody had shot ether and broke the pistons, so we are going to move his crank and connecting rods and pistons and put it all back together. ~Bill Hewitt