03 MCS 162000 miles . Today I started having valve train noise( clack clack ) at start up along with a rough idle. It happens even if the car has only been sitting for 20 mins or so . The noise and rough idle lasts about 20secs . After the initial issue the car runs perfect with no more noise. I'm thinking either a clogged oil channel or low oil pressure but being a mini who knows . Any help or suggestions appreciated

 

Mine (2005 JCW) does this on about 50% of the engine starts, and it's got less than 21,000 miles on it.
I normally bring up the idle speed until it goes away. Once on the way, it's normally gone. BUT...as you say, you stop for lunch somewhere, back into the car, start the engine, chain slap again, until the rpm comes up.

I'd be interested in an actual fix, as it's annoying, and not good on the chain or the guides.

Mike

 

So you're saying it's timing chain slap and not the lifters. It sure seems like it coming from the top of the engine

 

This morning on cold start up no noise ??
After doing some research I'm thinking maybe it's the timing chain tensioner . Fairly easy to change so I ordered on

 

Just restarted warm and tap tap tap . That's a mini for you

 

For anyone interested. I replaced the timing chain tensioner and thought it was fixed . No issue for many starts until yesterday . It happened again on a warm start and seemed to last longer. So now I'm thinking there's an oil passage getting blocked.
I ran a can of seafoam thru the pcv hose and got clouds of smoke . So far so good . Tomorrow I'm seafoaming again then changing oil and filter along with some liquid molley. also disconnected my catch can just incised it's introducing fragments of the stuffing inside. ordered a new one to be safe