Mustangmaster

Ever since I have been using full synthetic oils, my engine ticks more. Now I have blue smoke on some engine startups. I've googled blue smoke on startup. Some say bad valve seals, some say change the PCV valve. What about changing the fuel injectors? Or would that be black smoke?

JIM5.0

I hate to say it, but you might indeed be burning oil. lack or blue, smoke is supposed to be white.
This is my guess, but I could totally be wrong. I have never made any blue smoke in any car I have driven; just some excessive white smoke from a drop of oil passing into the cylinder by bad rings. This did reduce my oil level.

I would watch you oil level on a consistent basis to see if you are actually burning oil. Blue smoke? I guess with synth oil, it might be possible to be blue

siggyfreud

The lower viscosity of synthetic oil may be getting past your aging valve seals. When you're only getting smoke on start up, it's generally an indication your valve seals are worn and allowing oil to slowly drip into the valves overnight.

Mustangmaster

I guess I'll keep an eye on the oil. I just changed it using Pennzoil Ultra. Castrol Edge previously. Didn't have any leakage that I remember and I let the Castrol Edge go 10,000 miles. Sunday I take a trip to Florida from Virginia. We'll see if it lowers.

marcuskeeler

As Siggy says, the thinner oil is running into the bores past the valve seals and down the stems when Hot. When you start it up the oil collected is burning away.
To be fair to the motor 83,000 miles is pretty good and I wouldn't be surprised to see that occuring. You'll likely find that it does it on and off, not constantly. In theory it shouldn't make a difference but in practice it does depend at what point of the motor rotation it stops at when you shut her down, some valve seals will leak more/less dependent on valve position.

What should you do? Leave it. Unless you are desperate to have the seals changed, but then you're getting into the whole "should I just have the whole head[s] refreshed and so on".
It'll go on for many thousands of miles like that, I wouldn't sweat too much.

You could go back to a thicker mineral oil of course which might, or might not reduce the seepage...

Mustangmaster

Thanks Marcus, it is random. Sometimes it smokes, sometimes it doesn't. Maybe I should go back to the standard Motorcraft Synthetic Blend factory oil.

marcuskeeler

- Black smoke is usually an over-rich fuel setting. These days it's rare to see now we are all fuel injected. Cars with worn carbs would often belch Black smoke as they lurched down the road. You see Forced induction cars eject Black smoke between hard shifts quite often.
- Blue smoke is usually Oil burning
- White smoke is usually Steam which all cars do as they burn off condensation in the exhaust system
- Light Brown smoke is usually Carbon deposits in the heads/headers being ejected, mostly at high RPM

Cats, when up to High Temperature, can mask low levels of oil burning, the extreme heat of the cats literally atomize the oil as it passes through.

Mustangmaster

Ha ha, white smoke is something we used to see in our exhaust pipes back when we had much higher octane gas back in the 70s and before. I remember having white pipes in my old 67 Mustang. No more.

marcuskeeler

White staining inside the tailpipes used to come from the lead in the gas. Unleaded nearly always burns jet black at the tail pipes

Unleashedbeast

Ultra has a very aggressive cleaning additive, and you may be experiencing a removal of sludge buildup. When the engine is cleaned around worn or tired seals it will allow thinner oils to pass by. IMO, allow Ultra to do it's job, but after 5,000 miles change it to a 100% full synthetic 5W-30 oil of your choice. You should not see anymore oil passing by your valve seals, and no more smoke (this is assuming you are using a 5W-20 now). A top shelf 5W-30 100% synthetic will be more efficient than a group II syn blend or a group III fake "hydrocracked" synthetic 5W-20. This thread will better explain more about it.

Increased oil weight, and MPG improved, Possible?

I would also suggest a top engine cleaning right before you change the oil. This will remove all oil/carbon buildup from your intake manifold and intake valves before the fresh oil is poured in. The combination of PCV blow by and valve seals leaking make a mess. Seafoam is a good option, but AMSOIL Power Foam works even better.

AMSOIL Power Foam