OK boys and girls, its time for my monthly calamity! Let me bring you up to speed....

My new 350 is starting to smoke out of the driver side exhaust. (true dual exhaust). Nothing major, but noticable. The smoke is kinda like cigarette smoke, wispy like... While it sits and idles, if I gun it, I will get a noticable little cloud. --This is NOT coolant. I say again, it is NOT coolant. The pipe is also rather sooty.....SOOOOOOO...

I checked my mixture, she seems to be running fine, my 'Brock 600 is pulling 15 inches of vac.....

I pulled the driver side plugs. The number one plug was all sorts of oil fouled. (I mean almost covered in tar) Number three was dirty and number 5 took a wipe off. Number 7 looked fine. The engine is consuming about 1/2 quart oil a month. Now, the entire short block received a professional rebuild. Line honed, bored .040 over, new rings and pistons, etc etc. The heads are 'stock truck heads' as described by the guy who I purchased the engine from. I dont think the heads were rebuilt, but they were not some old nasty set off a junk motor either...

Where do you guys think the oil is coming from? Is there a way to tell if its a valve seal versus guide versus ring?

Better be just a valve seal, because I need to save money for a new rear end!

 

If it smokes all the time, especially when you stomp on it, the rings are not sealing. If you coast (foot off the gas) down a hill letting the engine do the braking, and blue smoke is following you, the valve stem seals are not holding, or there is too much clearance between the valve stems and the valve guides

 

Valve seals are leaking on that head, or leaky valve.
To check for bad/gunked up valve is easy and can be done in most driveways.
Car in park or neutral if its a stick.
Remove spark plug from suspect cylinder
Install adapter for compression tester in spark plug hole and then hook to shop air hose- keep hands clear as engine may slightly turn over to push piston to bottom of cylinder.
Then get your ears on........
Is air coming out of carb/throttle body opening? If so bad intake valve.
Coming out of exhaust pipe of same cylinder head? If so bad exhaust valve.
does air come from out of oil filler cap or through crankcase vent? If so bad rings.
If problem is in valves, here is a solid way to try to eliminate gummed up valve.
Run engine untill warm.
Then trickle approximately a quart of water into the throttle body or carb opening. Engine will try to stall, so keep rpm's up while doing it. Do it SLOWLY! do not over feed water.
As the water enters the cylinders, it will evaporate and expand at an extremely fast rate- actually steam cleaning the inside of the cylinders and the valves. ( its the difference between using hot or cold water in a pressure washer- hotter is better right?) well same thing.
Engine will heat up fast so keep an eye on engine temp.
If problem still occors, then recomend replace valve seals. If problem still occurs, pull the heads and have rebuilt.
If problem is fixed after clean out, then take for a good drive and rev the crap out of it. This will blow the rest of the gunk out of the engine.
Hope this helps.

 

Good to know. Ill try it. Thanks again. Im still thinkin its a nasty valve seal b/c of the white puff on start up.