2003 Hyundai Sonata Exhaust Smoke on Start-ups only

CPOISE

MEMBER
2003 HYUNDAI SONATA
6 CYL
FWD
AUTOMATIC
142,000 MILES

I have a 2003 Hyundai Sonata with approx. 142000 miles. I recently changed to full synthetic oil. Since the change, on start-ups only after the car has sat for 4+ hours, a plume of bluish tinted smoke comes from the exhaust. I also have noticed since the change my oil seems to be burning more quickly. Any ideas?

1 Reply

ZACKMAN

MECHANIC
4,202 POSTS

At that many miles, you should have stayed with conventional oil. The molecule for synthetic oil is considerably smaller than that of the conventional oil. With that many miles, your piston rings and various seals and gaskets have been worn out and the smaller molecules get past through them more easily than conventional oil. That is why you see some smoke first time start everyday and why you are using more oil now than before. If it was me, I don't see spending quite a few of my hard earned money to replace the seals and rings just so I could use synthetic oil. I would switch back to conventional oil.