Hi, just last week my Disco started misfiring on cylinder 5 and 8. It was pretty severe - the SES started flashing intermittently, but it's been parked since.

Over the past few days, a number of large (quarter size) oil spots have appeared, covering an area about 2' square. My truck did have the oil pump alignment service bulletin, but was fixed by the LR dealer in '04.

Any thoughts or ideas on the cause of this? The engine had been oily in the past, but not to the point that it dripped on the ground.

I appreciate any help. Thanks!

 

 

Thanks for the reply - as I noted in my post, the oil spots are in an area of approximately 2'x2', so pinpointing the source of the leak or leaks isn't really possible. I suppose I could buy some dye to narrow it down to a smaller area.

I've had the DII for 13 years, and I've never had an oil leak that I couldn't locate the source.

I was just wondering if the sudden leak could be related to the cylinder misfires in some way - blown gasket caused by the misfires - a total coincidence - whatever.

 

If you've had it 13 years then you would know the history... Have the HG's ever been replaced? You're time could be up. Other areas to consider are front cover and oil filter area. Any work done recently? If so check those areas.

 

Common oil leaks are from the valve covers, rear lower intake manifold, timing cover, oil pan, rear main seal and cruciform seals. As well as power steering fluid from the pump.

 

fixed

 

lol, yep
If it's not leaking...it must be empty.

 

Yes, I've had the truck that long, I've never replaced the head gaskets.

I had the oil and filfil changed about two weeks ago. I'll check the filter and plug. Would the drain hole leak if they left the washer off the plug? I know it's supposed to be changed with every oil change, but I doubt a quick change place would do that.

​​​​Had an overheat scare about a month ago, replaced the thermostat, it was stuck closed, no problems after that.

There's nothing else I can think of.

Over the years I've replaced a lot of the ancillary parts.

I'll tighten up the valve cover gaskets and whatever else could be loose.

The thing that I don't understand is why it happened so suddenly. Up until 3-4 days ago, it didn't leak at all.

 

I'd be suspicious of the quick lube place. Start there.

 

BowRat - Do the following...get some kind of engine cleaner and clean the engine. Then, start to look around for any NEW traces of oil.

The misfires, well...that could be something related but, let's start with the low cost easy approach first.