BLX to BVY engine swap worth the trouble?


New member
Melbourne, Aus
2005 6sp, FSI 2.0L
Hey there,

Fresh to the forums. I seem to be in the need of either new piston rings or a new engine. Looking at as much material as I can, it seems like swapping a BLX (current in there) to a BVY might be an option. Even better if I were to swap to ECU. I'm barely a hobbyist though. I would be having someone do it for me as it is currently at a shop. Is this a super dumb idea? Should I just stick to a BLX? They're about 3x the price and way more mileage.

Full story:
I have a 2005 Golf, FSI 2.0L N/A BLX code engine. Recently purchased it about 4 months ago. Pretty low KMs at 113k. Had a PPI and all checked out. Was running pretty much perfect up until last Friday. Unfortunately, l went to start it, and it started super super rough. Turned it off. Cranked it again. Same thing. Turned it off. Left it until Monday when I could call around to get it looked at. Got it towed to a spot on Monday.

Two days later, get a call back and I'm told the piston rings are most likely fucked, if not more. Compression in the two outside cylinders is 120 but the two middle ones are 60-70. They say they've ruled out a blown head gasket between the cylinders because there's not exhaust gases leaking into the coolant. They also did a wet compression test, and found that the compression went back up, thus leading them to believe it is piston rings (if not worse). I'm curious about your guy's input on what you think about that. Would two fail at the same time like that? Also, the timing belt did not snap.

Going back to the top, I'm now looking at either fixing piston rings, or swapping the engine. There are BLXs around but they're way more expensive with way more mileage. My understanding is that these two ones are pretty damn similar if not the same. All I can tell with my green eyes and research ability is that the BVY doesn't have the same NOX capture system and the lambda sensors are potentially in different spots. Would swapping the ECU help with that? Is this whole pursuit of finding a different engine code frivolous?

Let me know if you need more info. Hopefully I'll be able to get it.