Well since the engine in my 87 iroc is blowing smoke I decided to check compression and change spark plugs. Compression was good in all cylinders but now the engine runs very rough and lacks power. It seems very much like a crossed wire but all the wires are in order, I double checked that all the plug wires are securly on the new plugs and I definatly gapped them all the same.

the comp is throwing any codes but the engine definatly is not running correctly.
I'm stumped.

 

How many miles on your motor? Blowing blue smoke? How was it running before the new plugs? How old are the plug wires? I've read that new wires can make a big difference. They can look fine and still be bad. Anyway, I'm sure someone on here will know what's going on. Good luck getting her running smooth again.

P.S. You might just be running rich, causing the smoking.

 

I myself would verify again that all wires are on the right cylinders, if that is OK, check or replace wires. My bet is you have a bad wire somewhere, I normally replace plugs and wires together just because of this.

 

Thanks guys, yea it was the wires.
the smoke is definatly oil though, it doesn't burn alot (2L in 5000km) but it smokes a lot. only when it's warm so that kinda rules out valve seals but i've heard its possible for them to leak when warm too.

compression is really good on it still, and very little air coming out the PCV so theres very little blowby. aparantly the engine only had 20,000km on it when i bought it.. so like 25,000km now?
I haven't does anything super abusive to it while I was driving it.
The odd street race and a few runs at the track is it.
It is getting worse though.
I don't know why it's smoking so much.
If I take a valve cover off (i know which cyl burns the oil) will I be able to visually tell if the valve seal is toast?

 

Glad you found the bad wire. As far as the smoke, normally if you are blowing blue smoke driving it is the rings, if it only smokes just after starting then goes away, it is seals. Like the other guy said, maybe rich, does the exhaust smell fuelly?? If your compression tested OK, I would think it is fuel related. BTW, what was the compression PSI per cylinder, and did it stay steady, IE, didn't go down.

 

the smoke smells very oily and it consumes a decent amount of oil.
compression is between 145-155psi in all the cylinders.
it is getting noticably worse as well.
a fwe months ago it began as a wisp that was barely noticable. now it's hard not to notice it, it leaves clouds behind it when i take off.

engine still has good power though
no mph drop at the track so far.

what causes the rings to fail? especially on such a new motor?

Is it at all possible this could still be a valve seal?

 

Compression is a little low but if all cylinders are 5% of one another I would feel that the compression is fine. So the rings being bad is not that likely. What does your plugs look like. Might help clue you in.

 

thanks for the replys bob.
plugs were burning good with a few cylinders having a light film of oil cakes on the top of the threads.

I pulled my new plugs after 200km and there is no sign of oil consumption yet.

 

Really sounds like fuel then. Sticky injectors? Gas mileage terrible?

 

I'm having a similar problem - car running bad after plugs/wires cap and rotor.

Which wires did you have reversed?

What gap did you use for your spark plugs?

I don't know if it's the .045 gap rapidfires or if (like you) I wired it up backwards. It misses bad under load, but seams to rev up nicely out of gear.

Thanks,

Don

 

I'd love for it to be a fuel issue.
however it definatly is not.
it burns a quantifiable amount of oil and the whole car reeks of burnt oil while driving.

I guess I just run it till it dies then go bigger and better

 

Hey Jer!

You might have a leak somewhere if you smell oil when you are driving. One litre every 2500 km is not bad, really. And worn valve seals (or guides) will let oil past whether they are cold or hot.

Didn't you just put vortecs on that engine?

 

Hey Todd, the smokey car is the new one i just bought, an 87 IROC

the vortec car is getting a new motor so i bought this to cruise with in the meantime lol

I've noticed that if i let the engine get up to normal temp at 180-190 it smokes REAL bad. im talking blue hazes everywhere i go. If i keep the engine cold (150-160) it only smokes a bit when i take off.

its definatly going out the exhaust pipes though, however none of my old plugs really showed signs of excessive oil combustion, none of the new plugs show any sign of oil going through them yet either.

no loss of power yet, it still runs good against my buddies cars.