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Contact between pistons

Posted: Thu Feb 05, 2026 12:10 pm
by GoodWillHunt
I bought a 1.6-liter petrol Mini Countryman for my wife not long ago, and I knew right away that there was a problem with no compression on cylinder 1. After taking the head off, I discovered that the exhaust valves had burnt into cylinder 1, so I replaced them with new BGA valves. The new valves appeared slightly thicker than the old ones, but I double-checked, so I knew they were the right ones. I lapped all the valves in, put the engine back together, and timed it. However, now there's a little notch when cylinder 1 approaches TDC. Is it possible that these are touching the pistons?
Much obliged.

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:11 pm
by davejacobs
Yeah, that's when the BGA nonsense starts happening again if it touches. I can tell you about all sorts of problems with BG.The engine's components—the valves, which are positioned near to the pistons for optimal air intake and exhaust—are best observed by inserting a camera into the exhaust port.

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:11 pm
by GoodWillHunt
I appreciate you getting back to me. I agree; I usually try to stay away from this brand, but they were the only ones I could acquire in a decent amount of time. Now I have to disassemble it and replace the valves with ones from another brand; I'm hoping the gaskets are fine because they haven't been heated, but I'll need to buy new bolts anyhow.
Much obliged.

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:12 pm
by davejacobs
unused head gasket, head bolts, and camshaft bolts

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:12 pm
by GoodWillHunt
Can I use a crushed head gasket again? I turned the engine over by hand; it has not been ignited yet.

Much obliged.

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:13 pm
by davejacobs
Absolutely not! I just couldn't take the chance.

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:13 pm
by davejacobs
:D :D :D

Re: Contact between pistons

Posted: Thu Feb 05, 2026 12:14 pm
by GoodWillHunt
Alright, I'm really grateful for your help.