After I got the error for the valve cover leak and replaced the part my cars exhaust turns a greyish white after running idle for over 15 minutes. After moving again it stops after 1/4 mile or so. Not sure if the change caused this or something else. I do have a yellow half filled engine warning on the tach display and showing no error codes or CEL. I'm not sure if that is related or no. The only extra I have is a Bosch catch can. Any help or suggestions appreciated.

 

I would check and see if you have any oil in your coolant tank or coolant in your oil. Smoke often times indicates a blown head gasket. you might also just need a tune up. (new spark plugs ect..)

 

I can't find any cross contamination and plugs were replaced less than 5k miles ago.

 

Is suspect valve guide seals more than a head gasket

 

How hard is it to check valve guide seals? Is there an easy way to check

 

Not and easy way to physically check them without a lot of tear down. But the symptoms are related to valve guide seals going bad, sit at idle for a few minutes, step on gas, smoke from tail pipe for a second or two then clears up

 

That's pretty much it but idle is about 10 to 15 minutes to start smoking.

 

If you are sure it is white smoke, it wouldn't hurt to do a combustion gas test with what coolant is in the reservoir. They make a few kits for testing this. That would tell you if it's a head gasket.

I'm not sure of a bulletproof way to check valve guide seals. Best thing I can remember from experience is to check the intake and exhaust ports visually and see if you can see an oil trail. If you see some, BINGO!

 

Something else I though of. Did you install any PCV block off plugs? If you install one on the intake manifold the engine + front of valve cover the engine will start to smoke after a while from excess crankcase pressure. I know from experience. Do not use those plugs. Stick with stock PCV system for maximum effectiveness.

 

I have a catch can not plugs. I was wary of installing them. I've already had to replace the valve cover due to the common leak in the back.