StratfordShark

I had all my plugs out at the weekend so I could turn engine more easily to re-tension belt.

I don't know if this is just because the engine had only been run for a short time on last occasion (just to get car on the ramps) but I noticed that all the plugs were oily despite being pretty new. In fact on any occasion I've had plugs out, they never have that nice dry, sandy look.

Oil pressure looks good on the gauge (max pressure at high rpm, drops to 2-3 bar at idle) so I'm assuming piston rings are OK, but I haven't done a compression check.

Forgive my ignorance but what else could allow oil to get into the pistons, and what;s the remedy?

Thanks.

RngTrtl

leaky valve guides would do it easily

WICruiser

If the plugs continue to fire OK and the oil consumption is not a problem I would not sweat the oily plugs unde the conditions that you decribe. It is pretty easy to get fuel / oil on the plugs when strarting or not running long enought to get the plugs really hot. If after a long rung you park it and pull plugs and they are oily then I might suggest you need to look at the source but if you start and idle the engine for any time when cold you will see wetness.

davek9

I concur with WICruiser, but would like to add that you can have great oil pressure and great compression still burn oil.

The piston rings that give you compression are a different set near the top of the piston then the lower oil rings.

Your oil pressure comes mainly from the main crank bearings, but also a good oil pump and what of type of oil viscosity you use, and outside/engine temp.

What can happen is someone will run a car low on oil and ruin the (lower) oil rings, then when properly filled with oil, the splashing oil now at a proper level (and splashing more) is allowed to pass by the warn oil rings which then goes directly pass the compression rings and burns in the combustion chamber. Blue smoke will show when under strong acceleration and deceleration.

Valve guides usually show when a engine sits for a while and it will burns oil (blue smoke) when started, as the oil sitting in the head tends to runs down the worn valve guide/seals into the combustion chamber.

StratfordShark

Thanks for suggestion - I'll try that after next good run.

I've never seen any smoke on start-up.

tomcat

I'd say the first place to look would be the rubber seals under the valve cover that seal between the cover and the opening (tube, for a lack of a better description) going to the spark plug. (edit: if there is oil in the tubes going to the spark plugs).