Recently I noticed the CRV (60,000 miles) spark plug #1 had moist dark oil deposits at the ends of the threaded part. #2 had dark DRY glazed deposits in the same area. All 4 plugs had the normal tan colored deposits at the center and side electrodes. This started after I topped off the conventional oil with a quart of Shell fully synthetic oil. I don't think it's worn rings, given the engine mileage. I'm thinking stuck piston rings, and the synthetic oil was purely coincidental. I think I can rule out the valves as the engine had new valves and new stem seals installed not too long ago. When we removed the cyl head then, there was no sludge seen, and the camshaft and its actuators were normal-looking. At the time, the oil pan was dropped and cleaned too.
I can change my own oil, so I'm thinking why not free up the rings by pouring some kerosene down into the combustion chambers, let them soak overnight, and then change the oil? Comments?
I can change my own oil, so I'm thinking why not free up the rings by pouring some kerosene down into the combustion chambers, let them soak overnight, and then change the oil? Comments?
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