So recently I bought new fuel injectors due to my engine having hard starts and sporadic idle. After I changed my injectors I was elated when my fiero started first try, and was running amazing, until I got out of it. I noticed tons of white smoke exiting the tailpipe, but it was not antifreeze it was oil. the wall behind it actually had liquid oil splattered on it and the barn was filled with smoke. Trying to research this was nearly impossible, so I instinctively threw money at the problem, more expensive injectors, as I had heard that might be the issue and even bought the metal vacuum lines from the fiero store, and new pcv valve. Well had the same issue, and i'm pretty sure now a vacuum leak. last option was to just beef the viscosity of the oil, so I put in conventional high mileage 10w-30 in.... and all that did was change the smell of the smoke. So i'm bummed and have a feeling it is an internal issue. I have good compression on all cylinders, so would there still be good compression if one of the o-rings are shot. Or anything else that somehow may be letting oil in...Valves?.... I'm looking for anything at this point. The car is a project that sat for some time before I bought it, if that adds to the possibility of something.
The typical way oil gets into the combustion chambers is via the head... so you've probably either got leaky valve stem seals or worn valve guides. Or both. Eh, it could be excessive blow-by sending liquid oil into the PCV system.
When does the problem occur? Cold startup, hot startup, after it's been running, all the time?
[This message has been edited by thesameguy (edited 02-15-2021).]
When does the problem occur? Cold startup, hot startup, after it's been running, all the time?
All the time. On startup it usually will be not that bad when first started, but within seconds, it just starts to billow. I can also let it run for minutes and it just keeps pumping out smoke.
Are you certain the oil isn't overfilled? Does the problem clear up after a gentle drive?
I don't think it is as it didn't smoke prior to changing the injectors, it just had a really bad idle. After I changed the injectors it started happening, and I didn't mess with the oil when doing the injector change. I have not tried driving it as I wanted to get it running good before I got it registered, but I could always try to move it around the block.
This sounds to me like something that must have happened when you were changing the injectors- Go over everything you did and look at which hoses/pipes go where......
[This message has been edited by cvxjet (edited 02-15-2021).]
I dont remember exactly but i swear i read something about if the PVC system gets clogged it can force oil into the intake. or something to the gist of that.
It definitely can on some engines, not sure that applies here. If the normal evacuation path for crank case pressure is blocked, it'll find some other way out. On some engines, that could be pushing air/oil out the fresh air path, on other engines that could be out something like a crank seal.
(Me = 10 year Fiero owner, with no idea how the PCV system on these cars works )
After I changed my injectors... I noticed tons of white smoke exiting the tailpipe...
The car is a project that sat for some time before I bought it, if that adds to the possibility of something.
Changing injectors would not cause white smoke (water), or blue smoke (oil). I suspect the white smoke is simply due to plenty of condensation in the exhaust system being burnt off.
I recently posted the following in a Subaru forum where someone was concerned about "a lot of condensation coming out of the exhaust in colder weather".
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It never fails to amaze me how often people post about "white smoke" in car forums. Have they never noticed this before? Here on the coast, where the air is quite humid, "white smoke" (ie steam) just pours out of everyone's tail pipes on cold mornings.
As has already been mentioned... unless your car's coolant level is dropping, don't worry about "white smoke".
[This message has been edited by Patrick (edited 02-15-2021).]
My thought was more entertaining the possibility of a head gasket failure, and oil and/or coolant entering the combustion chamber, or coolant entering the sump and causing the PCV to evacuate it.
I don't know, but I get the impression this car wasn't running often or at all, so my concern would be that these issues (whatever they may be) always existed, but the car simply hadn't run long enough for them to present. I've definitely gotten unused cars running well enough to finally determine why they stopped getting used... more times than I wanna count.
No matter what, checking off the basics is step one. Check fluid levels, double check vacuum hose routing, be sure the PCV system isn't obstructed. Then move on to the crazy stuff like block tests and leak down tests, etc.
I suspect the white smoke is simply due to plenty of condensation in the exhaust system being burnt off.
The only reasons I know it is not this, is from how thick the smoke is. It burns your eyes and smells awful. You can also see a haze of it probably 5 to 10 minutes after shutting off the vehicle in the barn, and floating off into the outdoors. Condensation usually does not have a smell and does not stay around that long.
My thought was more entertaining the possibility of a head gasket failure, and oil and/or coolant entering the combustion chamber, or coolant entering the sump and causing the PCV to evacuate it.
I don't know, but I get the impression this car wasn't running often or at all, so my concern would be that these issues (whatever they may be) always existed, but the car simply hadn't run long enough for them to present. I've definitely gotten unused cars running well enough to finally determine why they stopped getting used... more times than I wanna count.
No matter what, checking off the basics is step one. Check fluid levels, double check vacuum hose routing, be sure the PCV system isn't obstructed. Then move on to the crazy stuff like block tests and leak down tests, etc.
Yeah the car most likely sat for 10 plus years prior to me buying it, and I have never ran the car for more than 10 minutes, there is always the chance that something decided it was tired and went out. I will try to check over everything and try to diagnose it further. Thanks!
If you notice white smoke coming from your tailpipe constantly, even on warm days, that could be caused by an engine that's consuming coolant. Since coolant is at least partially water, it'll create a similar white smoke as it evaporates in the engine and exits the tailpipe. This points to a leaking head gasket.
Blue or grey colored smoke is typically caused by an engine that's burning a significant amount of oil. This can be caused by a blocked PCV valve so check it again. Try unplugging the crankcase vent from the PCV and see if the problem is reduced or eliminated. Fixing this problem is typically as easy as replacing PCV valve with a new one. If this doesn't fix the problem, it could be piston rings, valve stem seals, valve guides other components inside the engine.
One of my GT's has 107K miles on it. I get a puff of blue / grey smoke when I crank it after it's been setting for a while. It goes away pretty quickly and I suspect its from oil leaking past the old, hardened valve stem seals.
The only reasons I know it is not this, is from how thick the smoke is. It burns your eyes and smells awful.
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Originally posted by PontiacLT1:
...it didn't smoke prior to changing the injectors, it just had a really bad idle. After I changed the injectors it started happening
Is the gas in the tank all fresh, or did you just add some fresh gas to the old stuff? How long have you actually let it run for? Has the engine ever reached full operating temperature (with a 195°F thermostat) since you changed the injectors? Are you positive all the plugs are firing?
After letting the engine run for at least half an hour, it might be advisable to actually pull all the spark plugs and have a good look at them. The color of each plug would tell you whether each cylinder is (a) firing, (b) burning oil, (c) burning coolant.
I still suspect the car is simply burning off condensation and perhaps old unburned fuel that's collected downstream in the exhaust system. Of course, if the plugs aren't all currently firing, this would add to the stench of the exhaust as well.
Yeah, that seems likely. If the engine seems to be running okay, there aren't any oddball noises, and there aren't any fluid consumption issues I would at least let it run up to operating temperature, then check again. If it's been sitting for 10 years, there could be all manner of buildup in those combustion chambers and in the exhaust. Plus old bad gas... that stuff is not gonna improve things. It's probably totally phase separated and full of water. It could be a combination of things as well.... but if it's been sitting, you gotta at least give it a chance to warm up and clear itself out. When you've gotten that far, I'd count on taking things apart.... 10 years sitting is a long time for rubber .... lots of things will probably fail or leak or both. One of those thing could be valve stem seals, which are now sending oil into the combustion chambers.
[This message has been edited by thesameguy (edited 02-15-2021).]
Okay, after tinkering on it for a little bit, I have made a couple of discoveries. We plugged the pcv vacuum line and it stopped smoking, but now I have to figure out what is causing the pcv to allow oil to be sucked out. Any ideas on this. A couple of you were previously saying that the system could get clogged. Is it just something in the valve covers getting clogged, or is there too much vacuum. I also noticed that the car has the early style of the air breather tube, and it was disconnected when I bought it.
I do still have a sporadic idle, which does not help the case, but it does go away when it is driving around in first. I pulled on the egr diaphragm which caused the idle to stabilize at 3000 rpms, and idk if the idle has something to do with the egr or not, but does not seem to have any vacuum leaks.
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Here on the coast, where the air is quite humid, "white smoke" (ie steam) just pours out of everyone's tail pipes on cold mornings. 
