oil consumption

[FourEyes]

I have an 87 GT with 110,000 miles on the odometer. It is an automatic. Car has started really consuming some oil over the last 6 months to a year. Recently a new exhaust was put on (headders back) and water pump was changed. Timing cover had to come off so front main seal was reaplaced. The PCV valve was replaced. Car has synthetic motor oil so this oil consumtion is kinda expensive. The car does not smoke at all and doesnt leave a puddle or drip anywhere. Where is all my oil going? it burns 1 quart about every 1000 miles. I know the 302 is good for way more miles than i have on it. any idea?

 

[Daggar]

Yeah, stop using synthetic and try a high mileage blend for the next couple oil changes.

Report back after 9000 miles (3 changes).

 

[ninety15.0]

Have you just recently switched to synthetic? What happens is that when a motor is run on Dino oil its whole life is that the varied molecule chain lengths find their way into the crevices/pores of the gaskets and seals. Dino oil has chain lengths ranging from extremely short to very long....very inconsistent. The small chains fill these pores and act as a gasket sealer of sorts. Then you make a switch to syntheic which has a much narrower distribution of chain lengths (more consistent). That combined with the detergent packages in the oils can clean out all that old dino oil thats sealing up your high mileage engine. Now all of a sudden you develop leaks, start burning oil, etc....

Try switching back to a high quality dino oil or even a synthetic blend if you really want the protection. See what happens after a couple oil changes.

Also could just be that the valve guides/seals or rings are getting worn out. You may not notice it smoking...but i bet if you have someone drive behind the car while you get on it...you might see some smoke.

If you see smoke on start up and hard decel...chances are you have guide/seal problems. If you see smoke on hard accell you likely have worn rings or PCV issues.