Puff of blue smoke from exhaust

[jeepguy4276]

‘06 limited 192,000 miles. After it’s been sitting, with the engine cold upon first start there’s a puff of blue smoke. Once it’s been started or engine is warm there’s no issues. The previous owner ran synthetic oil in it, it’s not due for an oil change yet so I haven’t done an oil change. I’ve read this can happen with synthetic due to its smaller molecular structure. Should I go with this or could it be something else? It only happens at cold start. I’m hoping that’s all it is since I know it could be valve seals or rings, but unlikely rings.

 

[tommudd]

Synthetic causing it ?? LOL NO
at 192,000 valve seals are going or gone bad more than likely

 

[Ksat]

Next oil change, make sure you put the correct weight your engine calls for. Perhaps the wrong viscosity was used. Synthetic oil shouldn't have any difference in "resistance to flow" than old fashioned dino kind.

 

[LibertyTC]

Also ensure the PCV valve is clean. Remove baffle inside the oil filler tube if it still has one, any gunk down in there?
Overnight just a puff of blue smoke can also be indicative of blowby oil remaining in the PCV lines.
Any oil in them ??

 

[Aceofspades]

Valve seals. Viton is a good brand.

 

[Big Al]

Has anyone done valve seals, part numbers?
Gotta get a compression test done also to see if the rings and cylinder bores are toast.
My engine is consuming oil almost faster than filling up.
146,000 miles on the engine.
I can almost say check the gas and fill the oil.

 

[Johnny O]

Synthetic causing it ?? LOL NO
at 192,000 valve seals are going or gone bad more than likely

Agreed. This is almost always indicative of oil getting past a cylinder or valve.

on the bright side, as it progresses, the men in black that follow you will get lost in the smokescreen…

 

[jeepguy4276]

Also ensure the PCV valve is clean. Remove baffle inside the oil filler tube if it still has one, any gunk down in there?
Overnight just a puff of blue smoke can also be indicative of blowby oil remaining in the PCV lines.
Any oil in them ??

I’ll check the valve and lines. No gunk in the oil filler tube. It is just a puff. It’s not a smoke show or anything. I’ll look into this.

 

[Parkroad22]

‘06 limited 192,000 miles. After it’s been sitting, with the engine cold upon first start there’s a puff of blue smoke. Once it’s been started or engine is warm there’s no issues. The previous owner ran synthetic oil in it, it’s not due for an oil change yet so I haven’t done an oil change. I’ve read this can happen with synthetic due to its smaller molecular structure. Should I go with this or could it be something else? It only happens at cold start. I’m hoping that’s all it is since I know it could be valve seals or rings, but unlikely rings.

 

[Parkroad22]

Stale gas?

 

[jeepguy4276]

Stale gas?

Fresh gas. It gets used at least once a week, usually more but is not a daily driver

 

[Johnny O]

Tried the Techron treatment?

 

[jeepguy4276]

Tried the Techron treatment?

No I haven’t. Is that an oil additive?

 

[Johnny O]

No I haven’t. Is that an oil additive?

Gas additive.

 

[Parkroad22]

Fresh gas. It gets used at least once a week, usually more but is not a daily driver

Do you rev the engine just before turning your vehicle off?

 

[jeepguy4276]

Do you rev the engine just before turning your vehicle off?

Not usually. I guess I could by accident sometimes