This started recently. When starting up cold all is good and when driving all is fine. But when I say go get gas or park for a minute or two when already warm - when I start the engine there's just so much blue smoke it's embarassing. It'll go for ~10 seconds like this and settle down after that.
What could be the cause? Does the engine need a rebuild? Or maybe something like valve stem seals are finally shot? Any ideas will be helpful but overall I think of rebuilding the engine after the winter.
[This message has been edited by cebix (edited 11-04-2018).]
It's common on the V6. I used an oil additive and the smoke went away after a few months. I think the valve seals get hard or dry out. hot oil will sneak by more than cold oil. If you changed oil recently, perhaps your new oil is thinner than before.
[This message has been edited by Gall757 (edited 11-04-2018).]
Depends but what s your mileage on the V6 - The seals do start going bad early on these V6 as said; an easy weekend project to replace versa rebuilding the entire engine if your engine is still strong -- I' ve seen 200K on these engines run strong with that seal problem but still kicking ass -- All depends on what your budget and time you plan to sacrifice .... Good Luck ---
...when I say go get gas or park for a minute or two when already warm - when I start the engine there's just so much blue smoke it's embarassing. It'll go for ~10 seconds like this and settle down after that.
quote
Originally posted by cebix:
Yes, I also have a puddle of oil in the air filter.
First of all, make absolutely sure your PCV system is working properly. A plugged/sticking PCV valve could lead to crankcase pressures building, forcing oil into places it's not supposed to go.
Secondly, here's something I've done with my '84 2.5 (and then later to my '88 2.8 as well). Quoted from a post of mine at a non-Fiero forum...
quote
I have a 4-banger Fiero that had a heck of a problem with oil/blow-by entering the air filter canister. Oil would actually pool at the bottom of the canister. It was quite a nuisance. I had the valve cover off while doing something to the engine, and I noticed that the valve cover was baffled where the PCV breather tube plugged into it. However, this hollow chamber was obviously failing in regards to separating oil vapor from the rest of the crankcase gases. So I used a strip of metal hexmesh and folded it back and forth about half a dozen times, and positioned it securely inside this baffled area. The crankcase gases now all had to go through this multi-layered mesh before traveling up the tube and entering the air filter canister. Honestly, the results were simply unbelievable! I now find no oil in the air filter canister when previously it was pooling and needed to be drained.
The hexmesh I used was similar to what is shown in this following online image. The holes are about 1/4" in diameter.
Some times you get the opposite more smoke for cold start and less for hot start but is same problem... This is most likely bad valve seals and/or guides problems. Maybe valves themselves are worn too. Hot start can be more obvious but likely have some oil smoke when started cold too. Cold start can allow time so oil from valves to leak thru the piston rings to the pan so less or no smoke to start the car.
You can replace valve seals in the car but often only a temporary fix. You likely need a valve job @ minimum.
heavy oil in breather in air cleaner is often Not PCV. Is heavy blow by from iffy rings and/or valves. (Valve blow by is exhaust valves w/ bad guides etc.) PCV simply can't suck out heavy blow by from either and pressurize the crank case and valve cover(s) then pressure and oil goes thru any exit handy.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
What is the mileage on the engine??? Obviously a puff of blue smoke is oil entering the cylinders but the puzzling part is that your problem only lasts for a few seconds when starting not running. I would change the 30+ year old valve seals and see what results. This is not expensive and might save you in the long run.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
To check your seals run it up, in say 2nd gear to maybe 4+K and then back off the throttle and watch your mirror for smoke and then accelerate. If the saels are bad it will smoke. good luck
It's probably worn valve seals. But it wouldn't hurt to do a compression check first. I suggest doing the compression check first, because it would suck to remove and replace the head for the valve seal work, then find out you have to take the engine apart again to replace the piston rings.
Thanks for the suggestions. Sadly I won't have time anysoon to work on the engine. But yeah if I'll be removing the head for a valve stem job I feel it would be best to rebuild the whole engine by the way.
I rebuilt the engine last year and beside some other problems - this one stayed with me that I thought would definitely go away.
There's no more oil in the air filter, no puddling. Other symptoms remain - hot start wants to die, will often die in R or D without leftfooting the brake and giving it some throttle. Huge clouds of blue smoke for 10-15 seconds after starting hot. After that is running fine. Looks embarassing leaving gas stations to say the least. No oil consumption noted. Just 2000 miles done since the rebuild and ~1200 since the last oil change so can't really say for sure it's not eating oil.
The shop did a valve job and replaced the valve stem seals. And it's been smoking like that from my first hot start since the rebuild. Thought it's just a fresh engine thing but now I'm concerned. Should I look into it at this point or just let it ride some more miles? I'm doing a lot of short trips mostly commuting to work and the weather is cold and has been all the time since the rebuild in september/october of 2019 if that might mean something.
[This message has been edited by cebix (edited 03-15-2020).]
I rebuilt the engine last year and beside some other problems - this one stayed with me that I thought would definitely go away.
There's no more oil in the air filter, no puddling. Other symptoms remain - hot start wants to die, will often die in R or D without leftfooting the brake and giving it some throttle. Huge clouds of blue smoke for 10-15 seconds after starting hot. After that is running fine. Looks embarassing leaving gas stations to say the least. No oil consumption noted. Just 2000 miles done since the rebuild and ~1200 since the last oil change so can't really say for sure it's not eating oil.
The shop did a valve job and replaced the valve stem seals. And it's been smoking like that from my first hot start since the rebuild. Thought it's just a fresh engine thing but now I'm concerned. Should I look into it at this point or just let it ride some more miles? I'm doing a lot of short trips mostly commuting to work and the weather is cold and has been all the time since the rebuild in september/october of 2019 if that might mean something.
Were the valve guide areas checked when they replaced the valve seals?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Were the valve guide areas checked when they replaced the valve seals?
No idea. I think it _is_ possible that they might have only replaced the big intake stem seals and not the little rubber oring intake and exhaust ones. Would have to contact the shop about it but I don't think they will remember. The receipt just says that the valve stem seals were replaced. The engine was rebuilt in may 2019 but only put in the car and ran in september or october.
Anyway this was a total rebuild with new pistons, rings, bearings, new cam, etc. so I doubt they would miss a thing like that with a supposed total inspection of the engine. I also distinctively remember they calling me up _not_ to order new valves as they were good so I guess they inspected those thoroughly.
[This message has been edited by cebix (edited 03-15-2020).]
It was quite a nuisance. I had the valve cover off while doing something to the engine, and I noticed that the valve cover was baffled where the PCV breather tube plugged into it. However, this hollow chamber was obviously failing in regards to separating oil vapor from the rest of the crankcase gases. So I used a strip of metal hexmesh and folded it back and forth about half a dozen times, and positioned it securely inside this baffled area. The crankcase gases now all had to go through this multi-layered mesh before traveling up the tube and entering the air filter canister. Honestly, the results were simply unbelievable! I now find no oil in the air filter canister when previously it was pooling and needed to be drained. 
