When I start my RAV4, a smallish cloud of white/blue smoke comes out the tailpipe- smells like oil. However, this only happens on start-up, and only in the morning when the engine hasn’t been operated for 10-15 hours. I’m not burning through oil. Gas mileage is within normal estimates. Car has 78,000 miles on it. Mechanic says that a seal is probably broken and that the job could be in the neighborhood of $1000. He said I didn’t need to worry about it at the moment, and I was relieved to hear this as I don’t have a grand socked away. When should I be concerned about this-what will be the symptoms? Bigger cloud? Clouds at every startup? Burning oil? Lousy mileage? Thank you.
The price sounds a bit high to me and maybe he’s pricing the job by having the cylinder head removed. This does not need to be done; the valve seals can be replaced without going that deep.
It’s simply a matter of removing the valve cover, applying air pressure to the cylinders, and using a special tool to remove the valve springs with the head in place.
There is also something else that can cause this and it’s not as major. Sometimes, depending on oil type, driving habits, etc., sludge can develop in the top of the cylinder head in the valve train area. The oil drain return holes may clog up a bit and this allows oil to pool around the valve guides. Removal of the valve cover and a little cleaning can cure this problem. It’s no big deal.
If there’s no noticeable loss of oil I would not worry about it at this point. Hope that helps.