Club 80-90 Forums

Hi,

Went to servcie the van this weekend (1.9 DG) and found that there was oil coming out around the sparking plug on cylinder no 4. Plug was in and nipped up tight, so I guess that there was a fair bit of oil in the cylinder behind for it to be working its way out. Whipped the plug out and it was pretty oily, as was the plug in no. 3. Plugs on the other cylinder head were both fine. Strange thing is the engine is runnig fine...

Oil consumption is about 1l every 1,000 miles at present although I'm guessing this might go up now! Light blue smoke under heavy load.

I know its broken, and that I'm looking at a rebuild / replace (the water jacket seals are just starting to weep on the non-oily head!) but any ideas what has gone to let this much oil into the bore - pistons / valves / something else all together?

Cheers,

Alex

Two places it would normally come from, through the valve stem seals or past the piston rings.

Valve stem usually evidences itself as a puff of smoke after you have been on overun (coasting, foot off gas). As the engine rotates without throttle it causes a vacuum which will suck oil past the valve seals if they are weak, then when you go back on throttle this is burnt off.

Piston rings are usually a more consistent smoking, can be seen when revving hard at stationary if they are quite bad.

As you have oil under load I would suspect piston rings, compression and leak down test would diagnose which.

Cheers,

MM

I'd second that. Worn ring grooves and broken oil ring are what I'd expect to find. 1 litre per 1000 miles is using quite a lot if it's not due to crankshaft seal leakage.

I've replaced the crankshaft seal, so it no longer leaks! There was not much by way of improvement of oil consumption though.

Thanks for the assistance, means I am off to look for a new engine rather than trying to do a rebuild on the one I've got. Good chance to change this pesky webber the van came with too....

Cheers,

Alex

I would second worn or broken rings....pretty sure wasserboxers don't have valve stem oil seals?

Martin