I’m doing a water pump, oil pump, timing belt and seals replacement on a d16y7 with 220k miles on the odometer. After taking all the old components off and cleaning the surfaces I have noticed oil leaking past the main bearing, it’s a very slow leak that accumulates and finally drips down the side of the block. I originally decided to replace the oil pump because I assumed my oil leak was from a worn o ring in the pump housing, and it was, plus a leaking oil pan gasket. I thought I was ready to get a tall all the new parts and saw this and now I am at a standstill.

I understand oil has to make its way into the bearings for lubrication but does oil flow past them enough as to ooze past the bearing and bead into a small drip like it is now? In the morning when it was around 50 degrees Fahrenheit there was no leak there but as it started to warm up to around 80 degrees in the day the leak was apparent.

Before I started work on the engine it ran healthy and pulled good. There was normal valve train noise But no hard knocking like a worn journal bearing or rod knock.

 

It's fine, you are worrying over nothing at this point. The bearings are flat and so oil will come out the sides of them with the help of gravity. If you ever see the video of lucas oil honey, it shows how the oil drains out of the bearings causing start up wear and how the honey helps keep a light layer on the bearing to help reduce this. This may help you understand what you are seeing is perfectly normal.

Remember, when pressurized the layer of oil on the bearing is only like 1/1000th's of an inch thick, the excess is pushed out the sides to flow back into the pan.

 

That’s kind of what I was thinking but then I looked at the oil pump and it mates right up against where the leak is taking place, so does it just hit a was there? It’s confusing because if it is supposed to leak past normally like you say wouldn’t have a sure passage back to the pan and not leak up against the oil pump housing? I might be way over thinking this but I want to be sure so I don’t end up wasting time. Because if it needs a rebuild I can wait till I get parts and just rebuild the whole motor to freshen it up. However if it is normal for that to take place I’ll leave it be and continue to put it all back together and drive it till it dies.

Btw, I bought this car about 2 months ago. Previous owner performed a mini me swap on the car and for what it is, it’s pretty preppy and fun to drive, so I really don’t know the miles on the block are true or not. It has a d16y8 intake, d16z6 head, Brian crower small grind cam and a p2p ecu so the car is a Frankenstein build for sure. I’ve been performing a tune up on the car and so far so good. Things I’ve done are new plugs, new brake booster (vacuum leak), new quieter exhaust (that messed with it a bit), valve adjustment, timing adjustment, Clutch adjustment, all new belts and hoses, and lastly been working to replace water pump, oil pump, tensioner, timing belt, and can seals.

 

The oil pump is sealed by both an o-ring wich can give out over time and liquid gasket maker Honda Bond. Which too can give out. As for the bearings leaking, they don't have any way not to seep oil.

More oil goes through the crank and up to the head than gets squeezed out the bearings.

As the bearings wear it lets more oil through but the result is usually enough oil pressure drop that the rod bearings don't get quite enough oil and eventually starts rod knocking.

Honestly, I would just do the tune up, replace any leaking gaskets and fix any oil leaks like the oil pump o-ring and liquid gasket and drive her. Until you start hearing a rod knock, she should be just fine. The bearings last a very long time.