Help....my daughters 2005 Mazda 6 uses 2 quarts of oil every week or so. There is no smoke upon starting up or acceleration. I changed the PCV valve and no change. It was suggested that I try using straight 30 weight to see if it improved loss. I live in the San Diego area so cold weather is not an issue. I am inclined to do a leak down test but what a pain taking off the intake manifold.

Any suggestions/answers?

 

A few comments/questions:

• Two quarts of oil per week; how many miles per quart?
• If you're already running xW-30 in the engine, then straight 30 weight will not be of any benefit (oils like 0W-30 have roughly the same viscosity as straight 30 when at operating temperature).
• Why would you need to take the intake manifold off to perform a leak-down-test?

 

This a V6?

 

Yes it's a V6..I thought to perform a leak down test you had to remove the spark plugs and they are under the manifold. About 500 miles a week. A lot of stop and go.

 

Granted I've never seen the engine in the subject car, but I cannot say I've ever seen an engine with the intake manifold positioned in such a way as to not allow the removal of the spark plugs. Now, might there be an engine cover or two which are usually easily removed? Certainly. An intake manifold in the way? I'm thinking unlikely.

So, per your two posts, your daughter's car is going through a quart every 250 miles; yes, no?

If it was burning that much oil, you'd see a significant oily build up in your exhaust tips, and most likely be able to smell burned oil when anywhere near the car while it is running. Are you sure it isn't leaking oil somewhere?

 

My first car was an old '70 Mustang with the 302, ate oil like nothing else, was about 200 miles a quart if that. Trust me at that rate your not burning it if you cant see it, I saw it ALOT at every stop, start and anything in between, even have the fix-it tickets to prove it :P Shipo is right in my opinion that your not burning it but its leaking out, did you have the oil changed recently?

 

Is that an F4 in your avatar? Ok, as stated, that much oil consumption you'd see smoke, least pull a spark plug to see if it is fouled. If not that, You have a leak. Leak that size you should be able to find. Changing viscosity IMO won't do anything for your issue.

 

No leak, no smoke and vehicle just passed smog. Buddy thought that maybe catylitic was burning smoke/oil before it reached tail pipe. Very strange and I am stumped. I am going to go to dealer and ask question. Thanks guys.

 

It is possible the cat is burning the oil but you would have blue smoke at startup when the cat is cold still, do they give you a readout of the HC PPM when you get the car smogged (tailpipe sniffer) or is it just the OBD II hookup?

Disregard text above SEE POST #12

 

Yup, an FG-1 (the Goodyear built version of the F4U-1A); I took the shot from a sail boat well out in the harbor off of Camden, Maine as the Corsair was banking in to line up on us for a mock strafing run. When it went by the short hairs on the back of my neck were sticking straight out; very cool.