So I just got off the phone with a friend up in montana, he had purchased a 94Z28 m6 that didn't run, well apparently he had the LT1 rebuilt, and it's been running for a few months. He said the engine was just rehoned with a torque plate installed on it, he ordered forged pistons and some after market rods, he didn't specify brands, but he did say they used total seal rings, reused the crank, didn't say if he had it turned, new cam, lifter 1.6 roller rockers, u get the idea, the problem is he says he's getting blow by, I didn't know what to tell him other than bring it back to the engine builder, there's a ring issue or they haven't seated, they should've by now, and the blow by shouldn't be so bad that if you ride in the car you smell like oil. Any ideas as to what may cause this on a fresh rebuild? Like it says, he didn't go wild or anything. I told him there were guys here that would be able to help figure it out, so any help as always is much appreciated

 

Oh yeah heads are completely rebuilt too, says he used quality parts, didn't want to end up with this sort of result

 

Well hopefully they didn't take too much when it was honed. The PCV system working properly? Could be something as simple as that...

 

He says his pcv valve is new, and rattles. Is there something else he should do to check the PCV system? Apparently it's worse than I thought it was, he sent me a pic on my phone and u can literally see a haze. The shop that did the machine work is a really good shop, they did the work on a 350 for me when I was in montana, nothing fancy, just the decking and boring out of a 350 and they also did the balancing. That thing loved 7500 RPM. but anybody can have a really bad day I guess

 

Leakdown test will answer the question. He should make the engine builder do it, while he is watching them.

 

Possibly used the wrong valve stem seals.

 

Ok I'll tell him to bring it back and have them do a leak down test, and to make sure he watches while they do it. Thanx.

 

So it turns out that he had a faulty valve stem seals, and a bad valve, I've never heard of getting bad valves and them actually making it into the heads, but I haven't been around I guess. I'm kinda thinking it may have been damaged during assembly, dropped or something. But thanx guys, he had the shop do a leak down test infront of him as suggested. And sure enough. anybody here ever get a bad valve? I'm just curious about it I guess. I'm just wondering if they didn't try to cut corners and put in used parts.