I drive a 2007 Mazda5 with a manual transmission.I've been having problems with the car consuming oils for the past 6,000 miles. It consumes oil at approximately 2 quarts a week. I've taken it to multiple mechanics and tried everything possible (Yes, have replace PCV valve). Recently had a very seasoned professional mechanic take a look. He suggested that my valve seals were leaking. The oil is dripping onto the piston heads and burning off.

My question is this: What is involved in replacing the valve seals? Is this a complete engine rebuild? Or is this something easy to do? Or..

Thanks in advance.

 

Some engines you can replace valve stem seals in-place, others require the head to be removed.

In-place, you remove the camshaft/camshafts, then pump compressed air into 1 cylinder at a time to hold the valves in-place after you remove the valve spring. Your then free to R&R the valve stem seal.

 

After getting that resolved you need to do what the video says because your catalytic converters have had to work overtime and the oil is starting to clog them up:

Use lacquer thinner, not paint thinner! Not only will it help clean them, it will also help clean your O2 sensors. I Suggest a good cleaning of throttle body and egr while you are at it, as well as new spark plugs and ignition coils (do them now before you have problems later as they are labour intensive as well, and you are right there anyway--you'll thank me later when you don't have misfires).