Blue Smoke on Startup?
After the dealer fixed the tensioner issue on my car, for about 1 week afterwards I would get that puff of blue smoke. I even had black residue on my exhaust tips. I checked the oil level and it was above the full mark :nono: so I went back to them and they drained some out. Have not had the problem since.
The two quick source tests for blue smoke are:
1.) Bad Valves or Valve Seals, causing blue smoke at startup: Hot oil leaks into the combustion chamber after shutdown. This is what you are experiencing.
2.) Bad piston rings: Blue smoke is observed after running down a long steep grade in a lower gear: This is caused from bad oil scrap rings. The engine vacuum literally sucks oil into the combustion chamber around the faulty rings, and when you step on it at the base of the hill, it blows out the tailpipe.
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I do not understand why Ford recommends a 5w-20 oil for this engine. That is asking quite a lot from the valve seals to keep the hot and very thin oil from drooling around the valve seals after shutdown. A cheap fix for reducing the blue smoke is to increase the upper viscosity number, such as going to a 5w-30. This may actually be a better operating viscosity for the rest of the engine, as the 5w-20 is probably recommended for maximum fuel economy, rather than for maximum engine protection. Generally speaking, the upper viscosity number can very safely be moved up 10 points with a more synthetic oil blend. I would try the 5w-30, and if the blue smoke persists after startup, ask Ford for a valve job, perhaps with higher quality valve seals, such as the Viton Seal.
1.) Bad Valves or Valve Seals, causing blue smoke at startup: Hot oil leaks into the combustion chamber after shutdown. This is what you are experiencing.
2.) Bad piston rings: Blue smoke is observed after running down a long steep grade in a lower gear: This is caused from bad oil scrap rings. The engine vacuum literally sucks oil into the combustion chamber around the faulty rings, and when you step on it at the base of the hill, it blows out the tailpipe.
=====================================
I do not understand why Ford recommends a 5w-20 oil for this engine. That is asking quite a lot from the valve seals to keep the hot and very thin oil from drooling around the valve seals after shutdown. A cheap fix for reducing the blue smoke is to increase the upper viscosity number, such as going to a 5w-30. This may actually be a better operating viscosity for the rest of the engine, as the 5w-20 is probably recommended for maximum fuel economy, rather than for maximum engine protection. Generally speaking, the upper viscosity number can very safely be moved up 10 points with a more synthetic oil blend. I would try the 5w-30, and if the blue smoke persists after startup, ask Ford for a valve job, perhaps with higher quality valve seals, such as the Viton Seal.
Originally posted by Gearhead@September 24, 2005, 12:38 AM
This may actually be a better operating viscosity for the rest of the engine, as the 5w-20 is probably recommended for maximum fuel economy, rather than for maximum engine protection. Generally speaking, the upper viscosity number can very safely be moved up 10 points with a more synthetic oil blend.
This may actually be a better operating viscosity for the rest of the engine, as the 5w-20 is probably recommended for maximum fuel economy, rather than for maximum engine protection. Generally speaking, the upper viscosity number can very safely be moved up 10 points with a more synthetic oil blend.
PS: I also found it strange when I first discovered that Ford recommends 5W20 for this engine, I would have bet 5W30 would have been Ford's recommended oil for the Stang V8...
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