Hi All,

I recently purchased a 2009 R55 n/a with about 150,000 miles on it. The PO said he had owned it since 30K miles and has never done a timing chain replacement, so that's the first thing on the list. I'll be doing the work myself since it costs literally more than I paid for the car to get it done at a shop.

When I search for the timing chain kits, there are ones with just the chain, tensioner, etc. and there are ones with the VVT sprockets included for quite a bit more.

My question is, what are the circumstances under which you replace those sprockets? Obviously you'd do it if there was obvious wear or damage, but since I'm not familiar with the VVT system, I wanted to know if there's any other reason to change these, or if they're typically changed out with the timing chain. Is there an non-obvious area of wear to look for, or a way to determine if they're still serviceable?

I'm going to need to do the clutch and a few other items on the car, so I'm trying to keep the damage to my wallet to a minimum - any opinions or info on this is appreciated.

Thanks,
Nick