Changed my spark plugs today, and wow what a difference. Turns out I didn't torque the plugs enough on my prior installation, and oil was getting on the loose plugs. I guess the loose plugs and resulting oil must have interfered with power and mpg. On my test drive my car exploded off the line and mpg shot up. Important to not to over tighten but important to tighten enough as well to manufacturers specs. I used a digital torque wrench to 22 ft lbs. My car almost lost control there was so much more power! And I think my CEL after my header install will probably go away since the bad plugs were likely contributing to bad emissions...

 

Glad you got back the lost power. Wonder at what mileage you changed the plugs last time and what is your current mileage.

 

A loose plug shouldn't allow oil to get into the spark plug tube. I would check the valve cover gasket or the spark plug tube seal. If you are getting better performance, it's likely that it's because you're starting out with fresh plugs instead of one that's covered in oil. If your seals are leaking, then oil will eventually make it's way back down there.

 

Yes I'm sure my spark plug gaskets and valve cover gasket needs to be changed. I bought the gaskets but have been putting it off.

This one particular spark plug was so loose I didn't even need a wrench to unscrew. This plug was covered with oil. The other plugs were properly tightened and had little if no oil. This led me to believe that oil is getting past the threads.

I will check this spark plug in a couple weeks, and if oil is present I will do the gasket change.

I'm not too worried about changing the valve cover gasket, but the spark plug gaskets look challenging. Have you or anyone else you know done this before? Do you just dig out the old gasket? Any tips?

Thanks!!

 

Valve cover gasket change.
This is a good thread!

 

Other than the crush ring, what is a spark plug gasket. Are you referring to the coil boot?

 

There are rubber grommets pressed into the valve cover (from the inside). In these engines the spark plugs pass through the valve cover on the way to the head, unlike older engine designs where the outline of the valve cover is scooped for the plugs.. See the thread referenced above. Anyway when the grommets get brittle oil will seep into the spark well. I've got that job waiting for me now that the weather is warming in the midwest.

 

Hmmmm... Maybe my leaking valve cover is just due to loose bolts? And I did see several missing bolts too! Thoughts?

 

..I had this done last year & it's best to do them both at the same time. The valve cover will have to be removed to gain access to the tubes, if I remember correctly, my mechanic charged me about $150