A little oil and coolant leak has started on the driver side..so the '01 OB heads with 120k/mi will have to be taken off..out of curiousity, I hooked up my Leakdown tester and found two cyl. where at 8 & 10% leakage coming thru the exhaust..The rest of the valves where tight with no discernable leakage.. those 2 cyl had 2-3% leakage... the two machine shops I called (one that does subi heads almost exclusively) recommended that all the valves and seats be ground.. I had asked them if they test their work for sealing and both said they use the water test method.. (filling up the exhaust and intake chambers with water and if it does not leak, it is good to go)..why don't places use vaccum or pressure to check valve/seat sealing??..I was also told that subi valves do leak.. why get the valves done if you may end up with them leaking anyway??..am I missing something by asking them about the tightness of the valves after their work??...

I wouldn't worry about it - resurface the heads and put them back on. The mileage is not high enough nor the leakage severe enough to warrant the expense. Subaru exhaust valves exhibit that behavior but remember that the engine cycles very fast - the amount of actual leakage is very, very small - it may seem significant with your leak down tester but at operating speed it's pretty much inconsequential.

 

Filling the chambers with fluid and seeing if they hold it is pretty much standard. That's how I was shown to do it also with industrial compressor's, etc. Though we used a solvent tank in our testing.....

 

GD

Edited July 27, 201114 yr by GeneralDisorder