So, I recently bought an 06 Cooper S. Everything seemed fine for the first month. Then As I turn the car on one morning to get to work I hear a rattle. I didn't know much about them at this point, but I quickly start searching. I come to find out it's the timing rail/guide. I do the job and clean out all of the plastic bits from the pan and oil pickup tube. I go to turn the car on and everything seems fine. Then maybe 30 seconds into the car running I hear a crack, I quickly turn it off. I open the engine again to see if maybe I forgot to take a plastic bit out or something of that nature. Nothing, so I drive the car and the more I drove the worst that chain/cracking noise got. I thought maybe the rails were broken but nope, tension seemed perfect and I remember timing the engine the correct way.(I bought the timing kit) So I know that the cam sprocket had an arrow which lines up with the bronze chain link and the crankshaft sprocket has 2 arrows that line up with the 2 bronze chain links. So no slack on the black guide giving all of the slack to the metal rail/guide.
Idk what It could have been but the rattling noise seems to be the chain. It almost sounds like the chain is hitting the engine cover. HARD! I'm afraid I might have timed it wrong? I didnt check for TDC but Idk how that would make a difference because the cam sprocket has a notch which only gives you one position in which it can be and so does the bottom camshaft sprocket. Unless I was 1 full revolution out of time. Seems impossible as When i opened the timing cover, I didnt move anything much or spin any of the sprockets but maybe 1 tooth to get the arrows and links positioned correctly.

The noise was clearly coming from the chain area, I dont think I messed with the valves or anything. Everything looks good is what I'm saying but as soon as I turn the car on It made a super loud clanky, cracky, chainy noise if that makes sense. I did change the chain tensioner, and bolt.

Now I did the job again. Half way I can say because I just have the car disassembled. I tried timing it again by moving the chain back to line up with the arrows and bronze links and it seems fine.

Do you guys have any suggestions or point out things that I could have missed/done wrong?


Maybe it was stupid of me to not check for TDC? but again maybe someone can explain it to me better? because it doesn't make sense to me as the cam sprocket has a notch in which it can only go on one way on the cam itself. So even if you spin the cam sprocket to get to TDC you would have to spin the camshaft sprocket to get the arrows and links lined up correctly if that makes sense.


Again, any suggestions or comments would be greatly appeciated. Hopefully I didnt create a bigger problem. If I did then oh well.

 

Sounds to me like you timed it correctly with the colored links. Did you release the tensioner before you turned the car on? Does the timing chain cover look like it's been hit by the chain? Are you sure there are no plastic bits in the oil pump... that might cause low oil pressure and prevent the tensioner from working properly.

You could check the TDC from the plug hole. There's a line on the camshaft sprocket that should be level with the exhaust side of the head when cyl1 is at TDC.

The crank pulley damper could make such noises too when it fails, but as you've taken it out at least a couple of times now you probably would've noticed if it's in a bad shape.

BTW, did the crankshaft sprocket come out easily?

 

Ive done everything I can at this point, besides checking the oil pump. I did release the tensioner before reassembling it to make sure it wouldn't skip teeth. I didnt change the crankshaft sprocket, only the chain and cam sprocket. The chain seems fine and so does the timing cover, it is a little scratched up but that was from when the rails broke. Nothing I hadnt seen before.

Im afraid to say it but I think I may have rod knock. Ill quadruple check everything before I put it back together and if it persists then I can say its rod knock without a doubt.

 

If you've had low oil pressure due to the plastic bits blocking the oil pick-up or the pump itself you may have damaged the main bearings...

Extremely bad luck there. How many miles on the car? I replaced the guides on mine at about 100k miles when I changed the camshaft, and one of them was slightly broken... found the pieces from the oil pick-up mesh. I had had some chain rattle at startup before replacing the tensioner.

 

It sounds like you may have completed the correct procedure, but for the benefit of those who have not yet done this, here are the proper steps:

The proper way to set timing on the Gen1 Mini is to set all the pistons mid-stroke so they are all 'even' across all 4 cylinders - you can take measurements thru the spark plug hole to confirm this. Then you use the cam locking tool to lock the cam which allows you to attach the cam sprocket with chain and torque the nut. Between the pistons at mid-stroke and the cam locking tool, everything will be in sync.

Be sure the tensioner is properly retracted during the installation and released after installation.

What is more concerning is the 'plastic bits' that had to be cleaned from the pan. If there were plastic debris in the pan there is a very good chance some of the smaller particles could have circulated throughout the engine. Although you expect the filter to trap these particles, some may have escaped and entered some of the fine journals that feeds oil to the various parts including the bearings.

Here are some articles which may help! http://new.minimania.com/Search_Resu...0chain/default

If you need to order parts, everything is 12% off for April only, excluding sale items and special order items. Just use the Promo Code: CelebrateApril

 

Yup and that's exactly what happened. The oil light would come on. So I stopped using the car but I'm afraid that's all it took.

What do you think would be the best option for me?

It was my fault so the car was fine before it was in my possession.

I bought it for $4900 with 113k miles.

I dont wan't to buy a new engine at almost the same price as the car.

 

Honestly, because of the possible cause, that motor must come out, and since you don't want to buy a new one, I'm thinking you've got 3 options:
1. Rebuild the bottom end of that motor and have something that should last a long time.
2. Find a used motor from a wreck.
3. Sell it as is, and take the loss, at least you bought it at a decent price.

Good Luck