Very smoky when cold just had valve stem oil seals done but made no differance 2001 d9 model

There are three common reasons for oil on the plugs. A blown head gasket, worn valve stem oil seals and worn piston rings. The most likely reason will probably be the head gasket.
Check the coolant overflow tank for oil floating on top of the coolant. This is a sign of a blown head gasket.
For Valve stem oil seals check the following... On a Cold start you get a large thick cloud of blue coloured exhaust smoke. You also get the same smoke when going from idle to higher engine revs. Such as pulling away from a red traffic light after sitting waiting for traffic.
Does the vehicle use a lot of oil? Does it have excessively smoky exhaust gas, usually more of a grey/white colour, when driving? Has it lost power? Look in the engine air filter box. Is there oil? Worn piston rings sometimes cause 'blow back' where an oil/air vapour is forced back through the air intake into the air filter box.

Probably defective valve stem oil seals allowing oil to leak along the valve guides and enter the combustion chamber/exhaust system.

Valve stem oil seals tend to be more affected by time than mileage and some of the materials used have been shown to be adversely affected by some of the oil additives used by oil companies.

One further thing to note - inside the modern engine a large volume of oil is delivered to the top of the engine (valve gear) every minute and in order for the oil level around the valve gear to remain constant the oil must drain back into the oil pan at least as quickly as is delivered. A too high level can overwhelm even good valve stem seals.
Sometimes the oil return ports can become restricted...

normal running that warm up time. not stem seal problem unless it dose it all the time engine is running. could just be the engine needs a clean. try seafoam or fuel cleaner and do regular oil filter changes. if you are getting oil lose then check the cam cover gasket or the sump gasket. as these are the main leak areas apart from bain bearing seal. but there is gasket and bearing seal additives you can use to stop these.

start car when engine cold - place some paper in front of exhaust pipe.
If you see dots of oil you have a major engine failure with the lower block of your engine or the rings. This costs a lot of money to fix !
I sent my car to wreckers to be crushed when I had smoke and burning oil smell plus oil when it was cold.

If it is water when engine when engine cold you may have a cracked engine head , cracked head or blown head gasket.
Less expensive to fix but may require head to be re machined if head is warped. If head is cracked then head will need welding.
A cylinder compression test will confirm this type of head problem.

The carbon suggests that oil is finding its way into that cylinder and oiling/carbonising the plug.

The mechanic changed the rings so it's doubtful that the oil is finding its way into the cylinder, past the rings. The only other thing I can think of is that the valve stem guide is worn (this would allow oil down into the cylinder) or the valve stem seal is perished/worn.

The photos below are generic images. They are NOT of your car:




A valve in the valve guide. A worn guide can allow the valve stem to 'rock' and permit oil to trickle down the valve stem into the cylinder.



The seal itself - rubberised.

There's many different types of seal. General image below just for illustration purposes:



Bluish smoke indicates that oil is being burnt in a cylinder. To be honest, worn valve guides/worn seals are quite common. You say your car is misfiring? That would indicate quite a lot of oil is fouling the plug. In most cases there would be no misfire after just 3 days. The exhaust would cough out bluish smoke at start up and maybe on the over-run, when going downhill.

A short term measure is to try a can of valve seal additive to see if the problem temporarily goes away. Repair is the best option though.



Try a can of valve seal? It's worth a shot..

This happens when the vacuum in the manifold is at maximum and the air is drawn down past the valve stems into the combustion chamber. IT takes oil with it and so when you increase the RPM's ( moving off at lights)the burnt oil in the exhaust is expelled as a cloud of smoke . The fix here is to replace the valve stem seals that have gone hard/cracked and are no longer sealing on the valve stems

sounds like piston rings, if rings are in bad shape,will be at its worst when cold then will get better when it warms up. Should be some power loss as well. pretty easy rebuild. good luck

Value stem seals are under the valve cover.(under the top of the engine)

Worn value stem seals will allow oil to blow into cylinders during cold start.

NOT a job for beginner,

Oil in a cylinder is never good. There are several ways for the oil to get there and different prices to fix it.

Valve stem seals go directly around the valve and keep oil from the valve train from entering the combustion chamber. A worn or cracked seal can let oil run into the wrong place. Depending on how the camshaft and valve lifters are fitted, the valve stem is at the bottom of the camshaft and lifter. The overhead Cam models bury to valve stem deep inside the head.

Good practice would be to replace all seals at same time, but 1 cylinder could be done independently. But you are usually doing 90% of the work to do 1 set of seals. If a V-6 engine do the bad bank completely.

Head gasket, oil circulates through passages. Requires removal of everything above the head so gasket can be changed.

Bad Oil ring on Piston. Requires removal of head, oil pan, possibly motor to access crankshaft.

There are some tests which can help tell the difference between the problems. Some of it is visual so you need some disassembly for that. This is not going to be as simple as changing a waterpump or an Alternator. But the valve stem seals are reasonable and the head gasket is not so bad.

Can not say what labor will cost, but it will be probably 80% of the bill.

could be valve stem seals. when it sits the oil leaks down into the cylinders and is burned off when first started. isn't noticible when driving because not a lot of oil leaking into cylinders until it sits for a while and accumlates