Q.I have a 1972 Lincoln Continental Mark IV 460 V8 7.5L. When I start the vehicle each day, a cloud of smoke rises from the driver’s side exhaust manifold and quickly dissipates. However, the car idles rough thereafter. If I let the vehicle sit for a couple hours and restart, the smoke is less.
A.When you claim, “a cloud of smoke rises from the driver’s side exhaust manifold,” do you actually mean from the exhaust manifold or out the driver’s side exhaust pipe? The exhaust manifold itself should not smoke, although it might if the valve covers are loose or the valve cover gaskets are bad. This permits oil to seep out onto the exhaust manifold as the car is sitting, but once the car starts, the oil is quickly burned off. Later on if the car sits for a shorter time, it has less oil to burn off, so less smoke. If you pull your valve covers, also check for the flatness of the gasket surface on the valve cover. If the valve cover has been over torqued down, the surface can become warped and permit oil to seep out.
A cloud out the exhaust pipe at startup can be a few things, and it’s best to try and determine what kind of cloud you have.
A white cloud that smells like car exhaust is often simply condensation in the exhaust system and will dissipate after driving a few miles.
A bluish cloud that has an oily smell is often an indication of worn valve seals; as the car sits, oil in the rocker arm area drains down along the valve stems and pools on top of the valves if closed or drains into the cylinder if the valve is open. Once the engine is started, the oil is burned off.
A grayish cloud that has a heavy fuel smell can indicate an engine that needed to be turned over several times to be started and is burning off the excess fuel. Or it could also be a carburetor that is adjusted too rich or a choke setting that is incorrect.
More than likely bad valve seals. Oil is leaking into the cylinders down thru the valves. When you start the vehicle it burns it out.
Doing a valvejob should correct the problem. Also do a cylinder leak down check.
White cloud could also be a blown head gasket leaking antifreeze into a cylinder
Check your valve cover gasket or run your car shut it off then watch it see if something spraying on it
If you are going to do the valve seals check the oil return passages in the head might be plugged and if you do one side do the other it won’t belong be for there in the same shape.
My bad I thought you said out of the exhaust tail pipe , it’s probably just the valve cover
I have a 70 mark 111 , llook at what side the Somoke is coming out of , on that side of the engine , you have a bad lifter , either leaking oil when it sits , or collapsed , change all the lifters and pushrods on that side of the engine , not just the bad one , and before you change them , let the new lifters sit in a bucket of oil for 24hrs so the oil could prime them , let me know how it came out , Anthony