White blue smoke on startup & after downhill coasting

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four_am33

Member

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2002 Mazda Protege5

• Sep 9, 2013

• #1

Hello All,

Recently purchased an '02 P5 w/ 158,000km. One week out of the mom&pop dealer and I am seeing some white / blue smoke at certain times. After I coast downhill for a while, then apply the throttle, I get plumes of white/bluish smoke out of the tail pipe. This morning, on starting the car after 2 days rest, I got quite a bit of white / blue smoke. In both cases though, it clears up quickly.

Did some research on this... some point to valve stem seal, others say it could be a lot worse, e.g. headgasket. Otherwise, everything seems fine. Engine is smooth, idle is fine.

Any ideas? Appreciate the feedback!

 

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esnave09

Member

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2002.5 Mazda Protege5

• Sep 9, 2013

• #2

Blue smoke is definitely burning oil, so more than likely not the head gasket. Does your car overheat/run warm at all (above the halfway point on the temp gauge)? That would be another thing pointing towards the head gasket.
I'd say that sounds like piston rings, but I'm not completely sure. I'm basing this on the fact that coasting downhill turns off the fuel injectors so it would only be burning oil if the rings are truly leaking, hence the bluish smoke. Not quite sure about the startup smoke, since all the oil should've left the cylinders and there should be more gas than oil in there. Just my opinion though, far from professional. Good luck with finding it!

 

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thuzil

Member

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Mazda, Protege Heavily Modified

• Sep 9, 2013

• #3

Probably valve stem seals. Do you see lots of smoke?

 

i12drivemyMP5

<<<<<<< >>>>>>>

Contributor

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-- 03 P5 / 23 CX-5 --

• Sep 10, 2013

• #4

Valve stem seals are first thing to go in most cases. Worn rings will yield black smoke, not white & if you have no faunky water in overflow and overlfow is not losing water then it probably isn't a head gasket issue.

 

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esnave09

Member

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2002.5 Mazda Protege5

• Sep 10, 2013

• #5

^^ These make more sense. My bad. I was thinking the wrong thing when I heard valve stem seals.

 

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four_am33

Member

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2002 Mazda Protege5

• Sep 10, 2013

• #6

Coolant looks good... thus chances are it is not a head gasket issue. Car is going in to Mazda for a diagnosis soon. Will update.

 

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kamesama980

Member

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2002 Protege5

• Oct 3, 2013

• #7

Textbook valve stem seals. 1. smoke on startup. 2. smoke when giving throttle after high-vacuum (idling or casting). blue/grey/white smoke is oil whether it's from the stem seals or rings. black smoke is oil or more often fuel. truly white smoke is coolant.

I've had the same thing in 3 cars (albeit the youngest was a 1990 so 20+ years old). don't make em like they used to...