smokes in the morning or when sits for hours
Asked by dinx Mar 23, 2010 at 07:10 PM about the 1993 Mazda MX-5 Miata Limited
Question type: Maintenance & Repair
runs great other than that that it smokes for about half mile or so in the mornings or when i let it sit for a couple hours it is oil you can smell it . other people with this kind of car has same problems ive heard from oil rings sticking to valve guides , and valve seals. any help . thank you for your time .
4 Answers
It sounds like you need some new valve guides. You will need to pull the head and have new ones pressed in. There is a possibility that there could be a blockage in the PCV system. This could pressurize the head and force oil past the guides.
thanks its diff. better than rings
jclemmojoe answered 14 years ago
It sounds like the oil that puddles in the head when you shut off the engine is leaking down past the valve stems into the combustion chambers. This oil will normally burn off when you first start the engine after it has set awhile, hence the smoking for a short period of time. Larry is right on about valve guides, but I'll suggest a less expensive fix that might give you some temporary relief. The valve guides are generally bronze bushings that are pressed into the head to keep the valves centered to the valve seats. They are not the sole seal that keeps oil out of the combustion chamber, however. There are also valve seals that are made of neoprene or other synthetic material that really do the sealing. These deteriorate in time, particularly if the valve guides are worn significantly. Sometimes, mind you I said sometimes, you can get by by just replacing the seals. This can be done without removing the heads which is obviously a lot less expensive. Good luck Joe
