Today we have Chris lovely Imola Red E46 M3 for an inspection 1 service with valve clearance adjustment. This usually carried out every 60k at the inspection 2 service, but Chris is keen to have them checked and adjusted to keep the car running at maximum performance.
Please note that this is not intended as a guide on how to do your valve clearances, as this is something we advise is done by an experienced mechanic. This is purely for interest purposes only.
The valve clearances need to be checked with a stone cold engine to obtain an accurate measurement. Doing this with an engine that is still warm carries risk of your measured tolerance being incorrect, leading to adjustment being incorrect.
So lets start by removing the rocker cover –
Remove this oil feed pipe. Don’t lose the 2 copper washers!
Once the rocker cover is removed you can start the valve work.
With each valve you check, the camshaft lobe must be pointing upwards. then insert your feeler gauge to measure.
If you find a clearance that is out of spec, you have to remove the tappet/shim and measure it, then install a smaller/larger size as required. The measurements are done using a micrometer.
Here is a shim being measured in the micrometer.
These are the tools required for the adjustments. A Shim set, a shim removal tool, a set of feeler gauges and a micrometer.