Smoking

[Timnmelinda]

Need ideas or suggestions

Bought my 67 Mustand/200/automatic 42,700 miles

no smoke no signs of oil use
restored car
upgraded to headers and duals
still no signs of oil problems
changed to dui distributor, did oil n lube change on car in the process overfilled oil 1 quart, corrected oil level and car smoke a lot at idle.

Seems to disapear wit rpms raised but at idle it is visible
ran the car a while to eliminate possible smoking from prior oil over fill
still smoking at idle, do not know what to do / look for now, I am out of ideas, would not think with 43000 miles it would be rings, and it appears to stop with rpms, do not think valve seals because when it is running and warmed it still does it.

Any ideas or experiences you can share?

Tim

 

[pedal2themetal45]

Maybe the PCV is sucking oil into the carb. pull the hose at the carb and see if it soaked.. In fact go and disconec the PCV line from the carb , plug the hole in the carb (temperaraly) don't plug the hose so the motor can vent and run the motor and see if the smoking quits.
just a thought
tim

 

[Timnmelinda]

have the carb hole plugged currently have a breather on valve cover no pcv valve

Tim

 

[CobraSix]

Color of the smoke?

Slade

 

[Timnmelinda]

Looks light gray smells very much like burning oil, (not white moisture based for certain) I have only seen it out in bright sunlight, it is not clouds like your typical oilburner but it is deffinatley smoke comming out

Tim

 

[JackFish]

Might be carboned up a bit.
When was the last time you took 'er out for a bit of WOT?

 

[Timnmelinda]

could be a possibility as it went from exhaust shop I ran it down the highway about 25 miles and was running it hard, off and on then upgraded distributor to dui, had it running a bunch at idle dialing everything in...then oilchange, then I had the car out and this is when I noticed the oil by both site and smell. It could be carboned but I do not know, new DUI New Plugs, I would think it would burn pretty clean, but it is worth a try running her hard to blow her out once

Tim

 

[CobraSix]

Grey/black smoke is actually usually a fuel condition. Before you go tearing around looking for an oil leak, make sure your carb is tuned up properly. THe fact that it seems to be mostly at idle makes me think you are running rich on the idle circuit.

Slade

 

[66 Fastback]

If I understand correctly, you plugged the pcv valve flow path. The enging is nothing more than an air compressor. The crankcase needs to vent somewhere. Pistons are compressing air in the crankcase on the downstroke. Back in the day prior to the PCV valve, they had a road draft tube that allowed the crankcase to vent pressure to the atmosmphere. Then they figured out they could pipe theis vent gas into the carb/manifold and help burn these vapors to help reduce emissions. This had the side benefit of reducing sludging and oil breakdown since less oxygen was introduced into the lubrication system. Anyway, you need to have some kind of crankcase ventilation, or you can expect to have some blowby by the piston rings and valve seals.
Doug

 

[Timnmelinda]

I do not have pcv blocked off, I have a breather installed which keeps venting functional, I am trying plugging pcv back in to see if it makes difference which it should not.

I also lean towards rich idle condition, I am going to actually take a closer look at choke and make sure it it opening and closing as it should (thinking of going manual choke.

Tim

 

[lightnin-boy]

Possible that the diapram is shot in the trans modulator that it would suck tranny fluid into intake under high vacuum situations... Also how old is the fuel pump? That could be another source of oil into the intake...

Kirk

 

[Timnmelinda]

The trans modulator was one of my first suspicions, how ever it checks out ok, as far as the fuel pump I do not know as have only had the car 6 months, I have not looked at it it may be oem

Tim

 

[lightnin-boy]

If you have the canister-style fuel pump, it can be dis-assembled and the diapham instected/replaced... not sure about the later ones.

Kirk