[Davieb]

Hi, new member here. I am about to attempt replacing the cam chain on a 1.4 N12 Mini engine. I have the cam chain kit and both VVT cam gears. i do have the cheap chineesium cam locking kit and have read they are not great so will see!

My question is that the chain kit includes a new crank gear but not a new bolt. Can the existing crank bolt be reused? If not where can I get a new one, a quick search on the net has not come up with any results. Many thanks.

Regards
Dave

 

[Davieb]

Many thanks Mike, picked one up this morning from BMW parts. Strange that they aren't included in the chain kit. Taken drivers wheel, wheel arch liner and cylinder head cover off so far. Fount top guide in 2 pieces, broken on the 90 bend where it bolts to the cylinder head.
I have ordered a 14mm 12 point spark plug socket should get it tomorrow, one issue I have is that I can't see any writing on the cam shafts. Tried cleaning them but might have clened it off? The cams have flat spots on three sides where the locking kit fits, am I right in assumng they are in the correct position when the flats are on the sides and top? I have rotated the crank so the exhaust cam is in this position and the intake cam is 15deg out when measured with a digital angle finder. Should I be worried could I have bent valves? Any help much appreciated.

 

[Davieb]

Thanks Mike, not got much done yesterday but have managed to get the locking pin in the flywheel. It's the exhaust cam that is out of time the intake lines up fine. I'm waiting for a compression tester and will do that before removing the old chain and sprockets. I have everything else ready, have removed the belt and friction drive and got jack ready to remove motor mount. Had to use the jack and some 10mm threaded rod and timber to release the tensioner. Stupid that a special tool is needed for the tensioner, whats wrong with a hex nut... With the torque settings for the crank bolt i'm going with yours but the Haynes book says 50nm plus 180?
Is it okay to do the compression test from a cold engine, jut being lazy as I will need to put the spark plugs back and I have taken the belt off now!

Regards
Dave

 

[Davieb]

Many thanks for the advice Mike.
I retimed the the exhaust cam for the purpose of the compression test. Thankfully all cyliders were between 165 - 175psi so i cracked on with the chain replacement. Managed to get a little more than 120deg stretch on the cam bolt with a 2ft breaker bar and that was an effort. Somthing that might be of use to anyone reading this and planning to do the job themselves, I had to remove the intake manifold to get the chain tensioner out and to be able to fit a socket on it to torque it to 65nm. There is a 10mm bolt on the underside of the manifold that needs to be undone as well as the 5 bolts on top. Its a pig to get to through the drivers wheel well.
New chain kit now fitted as well as new vanos gears, checked timing after first stage torque and rotating engine, had to adjust. Checked again and all good. Final 180 stretch on vanos gears and a little over 120 on crank bolt. Rotated engine and all lines up, phew! Reassembled engine, took a couple of cranks to start, sounds fine but revs were up and down on tick over. Car is still in the air as i need to refit front end and arch liner. Hopefully will do that tonight and take it for a test drive. I have read that the ECU needs to relearn the settings for new chain. Is there anything I need to do or just drive it. I have the autocom Delphi OBD scanner from ebay to read and reset engine codes, anything else I should do before driving it?

Regards
Dave