General Chat
Q:
Can someone tell me what the different types of engine smoking conditions mean as well as what the difference between blue smoke and black smoke is? Is blue smoke usually worn piston rings?
Also, how can you tell if the smoke is down to worn valve stem seals? Is it when it smokes on initial start up?
And finally, what does it mean when you get smoke when you change gear.
Thank you.
A:
usually under compression braking with smoking is indicitive of worn valve stem seals, becasue that is when more vaccume is being drawn pulling the oil past the seal. under accelration with smoking will usually be rings. the changing gears thing has me stumped.
A:
thick black can be caused by excessively rich air/fuel ratios.
1980 280zx w/L28ET MSnS-Extra, framerails are toast...
1982 280zx...newest acquisition...
1983 Maxima - just sits in the driveway these days...
A:
What about....
"Also, how can you tell if the smoke is down to worn valve stem seals? Is it when it smokes on initial start up?"
Later edit note: SEARCH indicates that smoking on start up is probably valve seals.
Jim
JR in Tulsa (4EVER Z)
73 240Z - L28, Triple Miks, 5 speed, 3.9.
83 stock 280ZX
Chaos, panic, and disorder---my work here is done!
Post Edited (Oct 11, 11:15am)
A:
White smoke can be running lean, black can be oil or extremely rich, blue is typically oil from bad rings.
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77 280Z - TEC3 Engine Management, Coil Packs, 3.1 Stroker, 550CC injectors, tripple throttle body FI intake, MSA Stage II Cam, etc...etc...
79 Fairlady - Rusty
81 280ZX - DD
A:
If it smokes blue when first started: Valve seals
If it smokes blue all the time: Rings
I used to have a Bug that would puff between gears. It was completely fine otherwise. I always put it down to having a header/free flow exhaust.
"The Law of Logical Argument: Anything is possible if you don't know what you are talking about. "
Early 74 260Z
90 5.0 Mustang LX vert (7up edition)
86 Isuzu Trooper
85 Kawasaki 900 Ninja
A:
Thanks guys. Now I will know how to translate smoke signals.
A:
Also, excessive fuel on startup can look a lot like oil on startup, but instead you can smell the raw fuel. My v8 did this a few weeks ago - my primary float got a crack in it and filled with fuel, thus dumping way too much gas in. What gave it away was I could literally hear it puddling up on the throttle plate with the pump on. It made a pretty bad smoke screen on cold starts - it was quite embarassing. Anyways, now it has a new float, adjusted properly, and it starts right up without any smoke.
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'82 280zx -- 400+hp 355 sbc / T-56
'72 240zt - T3/T4 hybrid / TEC-II / not much stock
'82 280zxt - Stock...for now
'77 280z 2+2 -- Ongoing battle; currently in the process of "ricing