Oil In Water After Repair?, <br /> Options

[alpha_omega16]

Hello, I am new to this forum and new to Toyota's but not to working on cars.

History:
Recently I replaced a headgasket on my neighbors 89 pickup with a 22-RE due to oil and water mixing. The motor had a rough life so I pulled it in order to replace anything else which might be wrong. Basically all the rod bearings were wiped, all the chain guides were broken and of course headgasket was bad. While the head was of I had it checked and machined, .006 was removed to make the surface flat. Every passage in the motor was cleaned and flushed.

Problem:
After about 2 weeks of driving with no issues we are now seeing oil in the radiator. This was apparently sudden since the owner has been checking the coolant every couple days. Yesterday the truck began overheating (never reached the H) and the driver stopped about a mile from home for 30min to cool, then continued the mile with no problems. Once home the oil was about 1 quart low and the radiator is completely full of water and oil (assume the 1 quart is in the radiator).

Possible Problem:
After doing some research I found that a common problem is the timing chain rubbing on the cover causing a coolant leak. While this is possible based on the marks on the timing cover it doesn't seem to be the case. Water would get into the oil one the other way around (please, correct me if I am wrong.)

Question:
What would cause the oil to get in the water? If I am not mistaken it would need to be a high pressure source (>10 psi) in order to do this. Could it be the timing case? Or did the head gasket blow again? This doesn't appear to be the same failure as before but it could.


Sorry for the long post but I just want to give as much detail as possible.

-Jason

[fourwd1]

Usually when the TC wears a hole thru the TC cover water does get in to the oil, and can trash the crank bearings. But I think you're saying you only have oil in the radiator and no coolant at all getting into the oil? I suppose it could happen.

You might be able to nail it down more if you do some compression tests on the engine and leak down test on the radiator. That way you moght be able to figure out if it's HG or TC Cover.

Even simpler, pull the valve cover off, you can probably see if there's a hole in the TC cover.