Hey guys first post here! I was at the shop to get an oil change and when they checked the spark plugs, there was oil in most of the cylinders. I ahvent been noticing much more than a HUGE loss in gas mileage (there is about 155,000 on it now). I believe that the tank holds 17 gal. and only at about 6 months ago i was getting over 400 mpg. Recently when i have filled it up completely i am only getting around 215 mpg. I am not sure if the cause is my faulty valves or not, any info would be greatly appreciated.

 

Oil in the spark plug tubes?? That would be caused by seals in the valve cover gasket or under the rockers.
What leads you to believe you have valve problems?

 

Just not sure what i am talking about lol. So if it is one of these two things is this the reason that I am losing gas mileage? How much do you think it would be to get this fixed? I only bought it for 4000 and if is gonna cost alot to fix i might just sell it.

 

Your first post was vague.

If the oil is above the spark plug where the spark plug wire connects to the plug, then there are a set of seals on the valve cover that will need replaced. You can pick up a set of those seals to change for about $20. Just unplug a spark plug wire and see if there is oil on the end.

The alternative is that oil is where the spark is generated and that would indicate that oil is bypassing the seals in the engine. That would indicate an engine problem.