I rebuilt my 1994 VTEC engine 50,000 miles ago, it now has 378,000 miles and still runs well but has developed an oil leak that is simply unacceptable. The rebuild replaced pistons and rings; heads were also redone with guides being reamed for new valves and seals. I estimate it's using about a quart now every 250 miles. I thought the problem was the cam seal as there was a pool of oil collecting below in a recess there. I went ahead with removing the timing belt,gear, camshaft assembly and replacing the cam seal, that seems to have stopped the leaking from there. However there is still oil emanating from the timing cover area so there are other sources. The rebuild kit I got was not OEM but looked to be good quality at the time, but now I am wondering whether these discounted kits do not have the same quality seals as Honda. Also, the engine I have noticed has a large amount of pressure at the valve cover; removal of the PCV indicates definite pulses of waste gas coming through the port, I am sure the PCV cannot scavenge this much volume so essentially the crankcase is under positive pressure. My first question is whether or not this could be leading to oil being blown past the oil seals. I did a compression test and the numbers were: 210/205/205/200 psi from 1 through 4 cylinders (dry). Wet readings were 227/225 for numbers 1 and 4. The Honda manual lists 178 psi as the nominal compression for a new engine so these numbers look good to me. One last thing, the exhaust needed replacement so I removed the system including the cat. converter. I ran the engine with an open pipe and this did not change the pressure situation at the rocker cover so a blocked cat/exhaust is ruled out. Any insight from the forum would be greatly appreciated as I hate to condemn my trusty Accord that has served me so faithfully for some 275,00 miles now! Main question then is: DO I have a blowby problem or do I mainly have failing oil seals under the timing cover?

 

I'd suggest running a leakdown test on each cylinder. See if there is pressure leaking by the cylinder. You may also want to do the the leakdown test with the piston all the way at the bottom of the cylinder to see if there could be an issue with the cylinder wall.

 

Thanks PAhonda. I did a leakdown and the number came in around 10% overall which I take as being ok. I broke down and took it to my local mechanic and had them check the crank, balance shaft and oil pump seals and they were already hardened after 50k miles. I could kill myself not having replaced them when I had the timing cover off and replacing the camshaft seal. Anyway, the car now is running well and leak free! Next stop, 400k miles

 

So I'm confused, it stopped taking oil???

 

Yes, the oil leakage was solved by replacing the front crank seal, the balancer shaft seal, and earlier I replaced the camshaft seal. The mechanic that replaced the two lower seals told me that the seals had hardened and were not sealing properly. I had purchased this rebuild kit from a supplier ERISTIC Gaskets in California. They looked like quality made parts and for the most part the car has run well but having major seals go south after only 50,000 miles of use is no good. Bottom line, if you're going to go to the bother of rebuilding your motor, invest in the quality OEM gaskets and seals. The pistons and rings seem to be holding up well at least for now