Hi,

I'm new here, working on my girl friend's 2009 mini cooper. It had a stalling/rough idling issue, and a bit of rattle when first starting up. I opened it up and found that the timing chain was loose, so I'm replacing it. When I got the timing chain out, the plastic guides were busted to pieces (the bottom parts, not the guide at the top), and just when I think I managed to pull all of them out, I feel down there an notice that the oil pump drive chain seems really loose.

My questions are: how much slack is the oil pump drive chain supposed to have? Since I don't live within 2 hours of a dealership, where is a good place to order parts online that will ship relatively quickly? Can I get parts from a BMW dealership too, or does it have to be a Mini dealer?

Thanks,
Sean

Hey Sean, did you ever get any info? If you're still looking for good parts sources drop a quick reply or PM me..

just something been

looking into so pics

wow 419 views no interest or comments

Very few get into them as far as we do. Only way for me to give an honest answer is to wait until my motor goes back together the middle of February. Other than that, at 185,000 miles. It was loose at ****. I thought, that can't be good.

Just curious, is the oil pump driven by the same chain as the timing chain that drives the cams?
Just where is this oil pump located and where is the oil pick up located and is it screened to keep debris out?

Driven by a separate chain from the crank. Pickup is part of the pump.

Ok, Looking at pictures of the pump I assume the pump sits inside the oil pan and picks the oil up from there and pressurizes the oiling system.
It's just difficult to see how it fits inside the oil pan from the pictures.

Yup. That's what goes on. It's tight. But thats how it goes.

I see a cylindrical shaped piece with a big thick spring behind the gear, could that be a tensioner? If so couldn't that be the reason for the excessive chain slack?

Pressure relief valve. Shim the spring it increases the oil pressure.

thanks for taking care of the questions thay do somewhat surprise!

Could a piece of the plastic timing chain guides gotten into the oil pump chain assembly causing it to "stretch"?

Highly unlikely, those things get hard a brittle over time. It'll chew them up the they'll get stuck in the oil pump screen. That's were I found some parts. If you have an old tensioner. There's a little trick you can do to them since they operate on oil pressure and spring pressure. I'll send ya a pm.

hey sprinters could you send me the info for the trick on the tensioner putting my 08 back together and if there is something i can do to help prevent this again i would like to do it
Thanks

On my 2009 MCS, the upper guide broke about a year and a half ago. I removed the oil pan and found plastic pieces from the guide in the oil pickup screen. I also noticed that the oil pump chain was very loose. I was asking the same question as you and came to the conclusion that it's normal for the chain to be loose. I put it all back together with a new tensioner and upper guide and it's been fine ever since.

Hey there, I might be able to help. I have done 3 mini's timing chains, and all of them had tensioner chunks in the oli pump pick up screen. All you need to do is clean them out, and snap the little cover back on. I do not believe that slack in the oil pump chain is significant. as long as the chain won't jump a tooth, you are talking about milliseconds of slack on the oil pump which I can't believe could cause a problem, its not like a critical timing like the timing chain or something more precise. As long as it spins up the pump, you should be fine, all of the ones I did had lots of slack...

I did the same thing as you did and found the oil pump chain to be very loose. Here's a video I took of it: . I was curious if all I needed was a tensioner but couldn't find the part anywhere and I was starting to assume it didn't have one. does anyone have the part number?

Edit: Never mind about the part number, I saw the photos above and got too excited. :(