TL;DR - should the PCV valve be sealed tight enough that a smoke test won’t leak through it?
Long version:
Now that I think I found the issue with the misfires on my 2016 SCV6, I wanted to see if I could find what might be registering in my GAP tool as a P0170 code, fuel trim on bank 1. This code only seems to crop up on long trips, and at the tail end of my last long trip, I could clear it and have it come back immediately. Here’s a 30-second log of what was happening there, for whatever help it is:
Thinking it might be a vacuum leak, I got a smoke test kit, and managed to rubber band around one side of the air intakes to seal it, putting the smoke input on the other side.
First think I noticed was that there was a bit of smoke where the plastic plenum joins the intake manifold. I remember having a hard time reinstalling that when I did my coolant lines, but I thought I had the clamp sufficiently tight in spite of the thing having rotated into an inconvenient position to reach the screw. No problem…pulled the plenum and will make sure it is tight once the engine is warm, because this didn’t really fix that leak. It’s tiny, and there are other tiny leaks around every place where a hose clamp is trying to seal a hard plastic piece to something…like the accordion pieces that attach the plenum to the filter boxes.
The other thing I noticed was that there was smoke coming out of the PCV, basically out one of the little rectangular holes on the clip around the perimeter of the PCV. I’d replaced that 4 years/20,000 miles ago when I did the coolant lines.
Is it “normal” for there to be some leakage there at the PCV?
Long version:
Now that I think I found the issue with the misfires on my 2016 SCV6, I wanted to see if I could find what might be registering in my GAP tool as a P0170 code, fuel trim on bank 1. This code only seems to crop up on long trips, and at the tail end of my last long trip, I could clear it and have it come back immediately. Here’s a 30-second log of what was happening there, for whatever help it is:
Thinking it might be a vacuum leak, I got a smoke test kit, and managed to rubber band around one side of the air intakes to seal it, putting the smoke input on the other side.
First think I noticed was that there was a bit of smoke where the plastic plenum joins the intake manifold. I remember having a hard time reinstalling that when I did my coolant lines, but I thought I had the clamp sufficiently tight in spite of the thing having rotated into an inconvenient position to reach the screw. No problem…pulled the plenum and will make sure it is tight once the engine is warm, because this didn’t really fix that leak. It’s tiny, and there are other tiny leaks around every place where a hose clamp is trying to seal a hard plastic piece to something…like the accordion pieces that attach the plenum to the filter boxes.
The other thing I noticed was that there was smoke coming out of the PCV, basically out one of the little rectangular holes on the clip around the perimeter of the PCV. I’d replaced that 4 years/20,000 miles ago when I did the coolant lines.
Is it “normal” for there to be some leakage there at the PCV?
