So I bought a 86 fiero not that long ago, it has 91k on it and I've put 1k on it myself. I've noticed recently that when I start my fiero, (and this only happens after it's been sitting for a while, enough for the engine to cool off), it will produce a white smoke out of the exhaust that has a very sour, pungent/putrid smell to it and the engine will kind of sputter a couple seconds before it starts idling normally. I'm really confused what this could be from? I know I added a oil additive not too long ago when I changed my oil but I'm not sure if that's even have anything to do with it?
... it will produce a white smoke out of the exhaust
White "smoke" is water vapor. Check to make sure your coolant level isn't dropping. If your coolant level remains constant, then it's just condensation that has collected in the exhaust system.
Blue smoke is oil. Black smoke is (excess) fuel.
[This message has been edited by Patrick (edited 06-02-2014).]
If it's just coolant it should smell more sweet like syrup.
If it smells really awful, you are probably burning coolant and have a bad/clogged catalytic converter (as when they go bad, break apart, and clog the exhaust, you will get a smell more sulfuric like rotten eggs or such.
Is it a 4 cylinder? Many of them poof a light colored exhaust smoke on startup (I would say light blue). Usually due a leak down of some oil from the valve seals. That is no big deal. Could also be a leaky injector dribbling gas so when you start it, it runs a little rough because it is technically slightly flooded until it burns that off. Could be a combo of both too.
Verifying the color of these tiny amounts of fluids after exiting the exhaust is tricky and depends on lighting IMO. Not quite as easy as telling the difference between a white smoking head gasket failure and an oil burning car with terrible rings.
[This message has been edited by 2.5 (edited 06-02-2014).]
Is it a 4 cylinder? Many of them poof a light colored exhaust smoke on startup (I would say light blue). Usually due a leak down of some oil from the valve seals. That is no big deal. Could also be a leaky injector dribbling gas so when you start it, it runs a little rough because it is technically slightly flooded until it burns that off. Could be a combo of both too.
Verifying the color of these tiny amounts of fluids after exiting the exhaust is tricky and depends on lighting IMO. Not quite as easy as telling the difference between a white smoking head gasket failure and an oil burning car with terrible rings.
It's not that tricky at all. Fuel burning in exhaust is black (carbon deposits in the exhaust gas), oil gives a blue tint to the smoke, and coolant is white (water vapor). If the exhaust is white and only happens on startup then it can be either condensation in the exhaust, or the beginnings of a blown head gasket or cracked head (small enough hole or crack can seal up when the engine warms up). If coolant level is going down, or there are bubbles in the coolant, then it's the head gasket or a crack. If coolant is fine, then it's probably just condensation burning off. If it smells a bit sweet, it's definitely coolant. If it smells awful like rotten eggs or something, then the cat is bad and needs to be replaced. Muffler could also be bad. If it smells less like rotten eggs, and more like urine, then probably rodents got in the exhaust, and possibly died. That will also clog the exhaust and make for rougher starts, and a horrible smell.
I checked the coolant level and it's been the same, the smell is definitely sulfuric and white. I recently tried replacing the exhaust manifold gasket and broke bolts off and I'm sure the leak from there isn't helping the situation. It just had me worried it was a blowing head gasket or a cracked block. But like I said it's definitely a rotten egg sulfuric smell.
It doesn't. It causes the smell. The white "smoke" is just condensation in the exhaust burning off at cold start. Or there is some coolant or water getting into the cylinders or exhaust. Could need a head gasket too, and if the cat isn't replaced soon, could get much worse. A small enough break in the gasket could be getting sealed up after the engine warms up, due to material expansion. I've had exhaust leaks in the past that do the same. Though if there was a gasket issue, I'd expect to see the coolant level go down in the overflow (or air bubbles). But if it's small enough, the loss might not be noticeably large enough, and it could take a long time for one to realize it's leaking coolant into the engine.