Delica Canada | Mitsubishi Van Club

The engine developed a "lope", lost power, and started smoking while climbing a hill. I first thought it was the injectors, but decided to test compression. All in the 300 + range. Took off the valve cover to check valve clearance. Some valves had very wide clearance. I had set them 2 years ago. The locknuts were tight. The valve with the widest clearance had over 1/4" - had to be turn in the adjustment screw until the top end is deep into the locknut to get the right clearance. The end looks ok; the cam rocker roller seems ok, as does the camshaft. I cannot guess what could be wrong. Any suggestions?

That's an odd one.

The rockers are quite weak, they're designed to break if the pistons should hit the valves. It's not unknown for rockers to suddenly break for no reason- perhaps yours are on the way out? But it would be strange for more than one to start doing that.

Thanks Growlerbernz. You got me checking the rocker arms and led to removing the shaft they are operating on. The valve that I was most concerned about had a failed bearing on the roller. This was the front exhaust valve. The other exhaust roller bearings are loose. My Delica has just 122K on it - seems very soon for a failed bearing. does anyone have any ideas why this has happened? I phoned my local dealer who said he may have some used rockers, but mostly intake. My intake rockers seem to be OK.