Hello,

I have a Mazda6 2004 (V6, 3.0L enginge) with 145000KMs (90000 miles) and it has been loosing oil...and I can't figure out why or how (neither can the Mazda Dealership)

In between the recommended oil changes (every 8000 kms) I am continutally having to add 2 to 3 L to keep the oil at a safe level.

I don't see oil dripping from my car or smoke coming out of my exhaust when driving on the highway

What I have done to try and solve this problem (within the last year or so)
- changed Crank Seal
- changed oil pan and drain plug
- changed PCV valve.

I am still left with the same oil loss...and the Mazda Technicians are at a loss also.

I was curious if anyone else had the same problem with there Mazda6...

Any advice/comments would be greatly appreciated.

 

Before you changed the PCV valve, was it ever changed before?

-Sheldon.

 

You changed the obvious things already. I would think if you had a piston ring issue that you'd see continual smoke. Have you done a compression check? Have you checked your coolant to see if there is any oil in there?

 

The PCV valve was not changed before I did it in 2009

I haven't done the compression check yet...but it was something that I was going to bring it up with the dealer. I wasn't sure if this would help diagnose the problem

I will check the coolant to see if there is any oil in it...thanks

 

Compression check will help you identify if you have head gasket or piston ring sealing issues.

If you find oil in the coolant, I'd suspect head gaskets.

Good luck.

 

Good chance with the PCV Valve never being changed, that it has caused engine damage. As sstlaure stated, get a compression check done. It will let you know the condition of the engine.

-Sheldon.

 

Probably carbon buildup on the scraper rings and oil rings. It is most likely burning the oil at rpm so not noticeable. A good decarbon of the engine using techron and/or seafoam with marvins marvelous mystery oil in the crankcase could help if so.