The other day I decided to get to the bottom of what was leaking oil over the right side of the block in my 300 Tdi Defender 90. It didn’t take long to track down.

There’s a black plastic thing attached directly to the rocker cover.

It’s the Cyclonic Cleaner, part of the crankcase breather system, Land Rover part number ERR1471. It’s easy to remove, just a single bolt and two hose-clips. On the tube that connects with the engine, there’s a small o-ring. That was my culprit! It had split and was spraying oil down the side of the engine. Now there is an official Land Rover part (LLO100000) for this o-ring, but a quick trip to NAPA had a replacement installed within the hour. Problem solved!

The filter is supposed to be cleaned every 12k or so, but I know it’s not religiously carried out. I cleaned mine in Coleman Fuel (as I don’t have any kerosene handy), and that did the trick. I left it to dry overnight, and the next morning, with just a few seconds of white fumes, everything worked fine.