Well, just got back from the Rover Indy and he said that all cylinders are getting perfect compression but the #5 cylinder is putting a little bit of oil on the plug causing a misfire. He said it could be a valve sticking. Can this be fixed without a rebuild? Will the ATF "oil" change clear this up?

 

Well if a valve is sticking then you would have lower compression on that cylinder than the others.
Oil on the plug will not cause a mis fire.

Lets start over...why was it in the shop?

 

have them do a cylinder leak down test as well.

 

It had a tiny bit lower compression in #5but not bad at all. It was in the shop to diagnose my CEL.

 

Can you share the Disco's age and mileage and how much oil do you add between changes, etc. does it smoke at startup for few seconds, etc.

A temporary quick fix that may work will be a spark plug with a higher heat range,but this may cause pre-ignition in the specific cylinder. That is if the existing spark plug is oily when you take it out.

 

It is a 96 Disco with 119,xxx miles. I add about 3/4 of a quart at the most between oil changes.

 

they should have then done a leakdown test, my guess that cylinder is pulling a tad of oil past the rings. too little compression can cause a misfire, but unlikely unless its down to like 80 or less psi.

 

When was the last time it had a tune up?
What plug wires did you use?

 

Oil deposits could be caused by your valve seals also, specially on the intake valve side ( oil gets drawn in during intake coz of the negative pressure ). One tell tale sign of this is when you do a valve job, pay attention to the deposit on the intake valve ( larger in dia vs. exhaust valve ). More often than not, the deposit is on the intake valve. Given the mileage on the engine if you haven't had a valve job yet.....

Misfires could be from alot of things, old plugs, faulty plug wires ( cracked, high resistance, shorting ) coolant leaking into cylinder, bad fuel etc. Need more info like diagnostic codes, etc.
Ed

 

I had a tuneup 4 months ago. Put magnacore wires on for ****s and giggles 2 days ago and it ran the same.