Blue smoke

What causes blue smoke, oil burning?? I've noticed I'm blowing out blue smoke in the mornings and when the car sits all day. But usually have to mash down on the gas and pump it a few times to get it to start. Sometimes takes 3 or 4 times of that to get it started. But once it's up and running it's fine.

Possible valve seals?

Valve Seals sounds like a good start. Do you have a catch can? I understand the 4.6L 3 valve motors like to eat oil as much as the LS motors. What heads do you have?

I searched a Mustang forum and found this. Hope it helps.......

do have a automatic trans could be modulator valve trans run on vacuum hose goes to intake pull hose off if you see fluid in the hose the valve is bad lets trans fuild go into intake when engine is shut off . when you first start it, engine will blow blue smoke after the car has set for awhile then disappear after start up

No catch, stock heads, and stick...

BrutalSierra wrote:

Valve Seals sounds like a good start. Do you have a catch can? I understand the 4.6L 3 valve motors like to eat oil as much as the LS motors. What heads do you have?

I searched a Mustang forum and found this. Hope it helps.......

do have a automatic trans could be modulator valve trans run on vacuum hose goes to intake pull hose off if you see fluid in the hose the valve is bad lets trans fuild go into intake when engine is shut off . when you first start it, engine will blow blue smoke after the car has set for awhile then disappear after start up

I heard the same thing. Thanks

How many miles are on it?

BrutalSierra wrote:

How many miles are on it?

Pushing 70k.

blue smoke is fuel. When is the last time you changed the spark plugs?

XplicitPerformance wrote:

blue smoke is fuel. When is the last time you changed the spark plugs?

Okay makes sense. I can smell it right before I get it started, guess I'm just burning it off once it's started. Changed plugs maybe 8-10k ago.

ProStang01 wrote:

XplicitPerformance wrote:

blue smoke is fuel. When is the last time you changed the spark plugs?

Okay makes sense. I can smell it right before I get it started, guess I'm just burning it off once it's started. Changed plugs maybe 8-10k ago.

what did you gap them at? Have you ever had it tuned? The a/f could be a bit on the rich side which would cause less than great performance and blue smoke.

Yep I was thinking the tune too. I have inconsistent idles (up and down). Not sure on the gap I'll have to pull one and find out. I think strictly tuned it way back...

ProStang01 wrote:

Yep I was thinking the tune too. I have inconsistent idles (up and down). Not sure on the gap I'll have to pull one and find out. I think strictly tuned it way back...

could use a retune. Also I would definitely check plug gap. Plug gap is critical with a blower car.

XplicitPerformance wrote:

blue smoke is fuel. When is the last time you changed the spark plugs?

I always thought blue was oil and too much fuel was black?????????????

I get em confused. You are right blue smoke is oil entering the cylinder. Black smoke is fuel....kinda crazy it sounds backwards doesn't it?

you are kinda right Dru. unburned diesel will come out white-ish blue. I have seen some weird cases where something entering the intake track like brake fluid, or the PCV leaking into the intake causing that. With the newer brake hydra boost systems its not going to be brake fluid but you can check other things. You can look at your plugs and see if its burning oil. you can also do a leak down if you think its the motor.

Blazonic wrote:

you are kinda right Dru. unburned diesel will come out white-ish blue. I have seen some weird cases where something entering the intake track like brake fluid, or the PCV leaking into the intake causing that. With the newer brake hydra boost systems its not going to be brake fluid but you can check other things. You can look at your plugs and see if its burning oil. you can also do a leak down if you think its the motor.

What's a leak down?

basically where they pressurize the cylinder and see if any thing is getting past the rings and if so how much. If its bad rings it may be time to rebuild.

Okay, I'll start with plugs tomorrow and go from there. Guess when it rains it pours... Hopefully nothing serious though...