Next I wanted to remove the timing chain cover to inspect the timing chain guides.
First you lock down the secondary chain tensioner. I used a small drill.
Engine strip and Inspection by
Sabrebuilder, on Flickr
You can then remove the camshaft sprockets and chain.
Engine strip and Inspection by
Sabrebuilder, on Flickr
Engine strip and Inspection by
Sabrebuilder, on Flickr
Engine strip and Inspection by
Sabrebuilder, on Flickr
Earlier engines do not have the friction plates but mine had these already fitted.
Then you remove the crankshaft bolt and pulley.
Engine strip and Inspection by
Sabrebuilder, on Flickr
Then you can remove the secondary tensioner. Some wear but already 100k+ miles so probably good for another 100k.
Engine strip and Inspection by
Sabrebuilder, on Flickr
Now with all the bolts removed you can remove the timing chain cover.
Engine strip and Inspection by
Sabrebuilder, on Flickr
(Photo after cleaning)
After a good look inside I was surprised to see the amount of slack in the oil pump drive chain....(apologies for the poor video)
Click on image below to take you to Flickr where you can view the videos
BMW M52 Oil Pump chain by
Sabrebuilder, on Flickr
There is no chain tensioner on this engine and I cannot find anyway of adjusting the chain tension. Googling suggest this normal but I cannot find a spec on what is normal. A new chain is only £25 so I decide to replace it.
After I fitted the chain deflection was down from 12mm to a much more acceptable 6mm.
BMW M52 Oil Pump Chain replaced by
Sabrebuilder, on Flickr
I think this was the main source of my rattle on start up.
That completes the planned mechanical refurbishment. Now I plan to clean up all the parts, paint them and re-assemble with new seals and gaskets.
...peter