Full Version: Smoke from muffler when shifting or not under power
When I shift, I get a little fog of blue smoke when I shift. When I am cruising and let off the gas, I get smoke. Please tell me its an easy fix. BTW, 1.8L fuel injected.
My guess is it is valve guides. That was the problem in my Ford 289
Bob B
Bob B
QUOTE(burton73 @ Sep 29 2017, 03:50 PM) 
My guess is it is valve guides
As long as the engine isn't overfilled with oil or the breather system is clogged:
While guides / valve seals will do this, it is mostly a piston ring issue. The oil control rings are worn / stuck or the compression rings have low tension. However, unless you are oil fouling plugs just drive it. When the plugs start to oil foul, it needs to be fixed as oil in the combustion chamber lowers fuel octane and increases compression, this leads to detonation and will burn pistons.
Race engine have low tension rings to reduce friction so you are getting extra HP for free. Piston rings seal under cylinder pressure and being race engines don't spend much time with closed throttle this works out fine.
You could do a leak down test, this is far better than a compression test as it tells you where the leak is occurring.
While guides / valve seals will do this, it is mostly a piston ring issue. The oil control rings are worn / stuck or the compression rings have low tension. However, unless you are oil fouling plugs just drive it. When the plugs start to oil foul, it needs to be fixed as oil in the combustion chamber lowers fuel octane and increases compression, this leads to detonation and will burn pistons.
Race engine have low tension rings to reduce friction so you are getting extra HP for free. Piston rings seal under cylinder pressure and being race engines don't spend much time with closed throttle this works out fine.
You could do a leak down test, this is far better than a compression test as it tells you where the leak is occurring.
That doesn't sound fun, (cheap).
Smoking on decel in a type 4 is almost always worn valve guides
Oil burning is the latest Formula 1 controversy, as it seems engine makers are using oil burn to supplement the strictly restricted fuel delivery rates. Oil consumption in those engines now represents additional power, but you don't see them smoking normally. 
gspreeman, yes leak down......fast and cheap. mark
The easiest and cheapest first level diagnostic would be a vacuum gauge. It can tell you a lot, or at least which direction to head in the next level of diagnostics.
Other option is to just watch your oil consumption, not including leakage. A quart 600 miles or less means you need a rebuild,now or very soon. A quart every 200 miles, means you needed a rebuild some time ago, and are living on borrowed time.
Other option is to just watch your oil consumption, not including leakage. A quart 600 miles or less means you need a rebuild,now or very soon. A quart every 200 miles, means you needed a rebuild some time ago, and are living on borrowed time.
QUOTE(Perry Kiehl @ Oct 1 2017, 05:59 AM)
The easiest and cheapest first level diagnostic would be a vacuum gauge. It can tell you a lot, or at least which direction to head in the next level of diagnostics.
Other option is to just watch your oil consumption, not including leakage. A quart 600 miles or less means you need a rebuild,now or very soon. A quart every 200 miles, means you needed a rebuild some time ago, and are living on borrowed time.
,PO didn't mention his oil level/consumption or the type of oil being used,are the spark plug oily or heavily covered in deposits.I've seen a lot of cases where incorrect grade or type of oil will cause the issue he has,I don't run anything but a good 20/50 full zinc dino oil.
If everything is otherwise ok a compression test would be the next step.
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