I held back replying to this as there was something I wanted to check on the truck first.
While I was there I checked the PCV. Clean as can be. PCV valve is a new one and on the passenger side the inside of the plastic tube is dry and clean. More anon on this though.
Original presumably. As per previous post, change of manifold gaskets pending and will take the opportunity to look as best I can at stem seals etc.
What I was checking was - I was curious to see if there was a leak between crankcase and inlet manifold that would show as vacuum in the crankcase. Sealed off the driver side PCV and via the passenger side after raising the rpm to circa 4000rpm and dropping the throttle, there was nothing in the way of vacuum. Had there been I'd have taken it as confirmation of a leak twixt crankcase and manifold. The lack of vacuum though is not proof that there is no leak.
With the driver side PCV sealed off there was some visible vapour emerging from the passenger side tube but not enough to create pressure. On re-connecting driver side PCV it ceased.
Whether it is at a scale that is indication ring blow-by worse that could reasonably expected is hard to say. Perhaps other can advise... (The engine was at operating temp after a brief run prior during the above).
This particular rabbit hole is one I've been down with my smart (all Suprex engines suffer oil control ring failure around 50-60,000 miles. Mine got to 75,000 before they caused burned exhaust valves on two cylinders). I tried all sorts (before valve failure) but re-ringing was the only cure. I honed the bores though it's not strictly necessary.
If rings are the problem on my Vortec - replacing them will be the route I'll go. In any case I don't believe they are gummed - inside the crankcase is spotlessly clean. Nor worn - hone marks still visible on the bores and very low mileage. Damage caused by the crankcase explosion is a possibility I can't exclude though.
Is a Vortec oil pan drain plug magnetic? (It's on my mind to pull the oil from the top and pull the plug to see if there's any ring fragments. If there are, there's little point in rushing to change the inlet manifold gaskets).
To put the crankcase explosion in some kind of context - it ruptured the timing cover but didn't displace the rear crank seal. There's scope there to have displaced inlet manifold gaskets and/or stem seals or possibly even cracked the manifold floor. Enough to damage oil control ring(s)?
While I was there I checked the PCV. Clean as can be. PCV valve is a new one and on the passenger side the inside of the plastic tube is dry and clean. More anon on this though.
Original presumably. As per previous post, change of manifold gaskets pending and will take the opportunity to look as best I can at stem seals etc.
What I was checking was - I was curious to see if there was a leak between crankcase and inlet manifold that would show as vacuum in the crankcase. Sealed off the driver side PCV and via the passenger side after raising the rpm to circa 4000rpm and dropping the throttle, there was nothing in the way of vacuum. Had there been I'd have taken it as confirmation of a leak twixt crankcase and manifold. The lack of vacuum though is not proof that there is no leak.
With the driver side PCV sealed off there was some visible vapour emerging from the passenger side tube but not enough to create pressure. On re-connecting driver side PCV it ceased.
Whether it is at a scale that is indication ring blow-by worse that could reasonably expected is hard to say. Perhaps other can advise... (The engine was at operating temp after a brief run prior during the above).
This particular rabbit hole is one I've been down with my smart (all Suprex engines suffer oil control ring failure around 50-60,000 miles. Mine got to 75,000 before they caused burned exhaust valves on two cylinders). I tried all sorts (before valve failure) but re-ringing was the only cure. I honed the bores though it's not strictly necessary.
If rings are the problem on my Vortec - replacing them will be the route I'll go. In any case I don't believe they are gummed - inside the crankcase is spotlessly clean. Nor worn - hone marks still visible on the bores and very low mileage. Damage caused by the crankcase explosion is a possibility I can't exclude though.
Is a Vortec oil pan drain plug magnetic? (It's on my mind to pull the oil from the top and pull the plug to see if there's any ring fragments. If there are, there's little point in rushing to change the inlet manifold gaskets).
To put the crankcase explosion in some kind of context - it ruptured the timing cover but didn't displace the rear crank seal. There's scope there to have displaced inlet manifold gaskets and/or stem seals or possibly even cracked the manifold floor. Enough to damage oil control ring(s)?
