I was told today by a machine shop that I went to for an estimate for a valve job to use 5W - 30 oil. The 10W - 30 that I had been using was helping the valve problem that I was experiencing according to them. Said it was keeping the valves open slightly and increasing the burn of the exhaust valves. Any input on this? Never heard this before.

Torqued

I doubt if 10W-30 caused the problem but that advice is based upon fact. In the early days of the G10 engine, they said 10W-40 was cool. There were a lot of burned valves and one of the contributing factors was overpumping lifters. That's when they changed the recommendation to 5 or 10W-30 with 5W-30 preferred. It's the second number that really matters in valve burning.

I run 5W30 in both my Metros.

I run 5W-30 in mine. I rebuilt mine back in 2007 and ran 10W-30. I did infact burn two valves, but that was because my cat was plugged.

Looks like the votes are all in favor of the 5W - 30 oil. So that's what it'll be from now on. Thanks, everyone.