[scottred.f32]

Had white smoke on startup and a misfire on cyl 3 after sitting for 5 to 20 minutes after warm. No spots on ground, had it in the air and no visible signs of leaking externally, no milky white in oil done 4 oil changes (liqui-moly) and not a spot of moisture, no oil in coolant.

Replaced the tank cap, ofhg and oil cooler gasket w orings. Now very little smoke at start, adding a 1/4 gallon coolant every 3-5 days depending on how spirited I drive and runs at a cooler temp at idle than at any speed after warm.

Any advice what to look at next? Hoping not head gasket. coolant system pressure test was normal.

Thank you

[thejeremyman9]

Were you driving hard before all this started the first time? Hate to say, but white smoke in exhaust typically only means one thing... coolant into the combustion chamber. And if you have continued coolant consumption with no leaks, that also points to head gasket, especially if consumption increases as you drive harder.

If you are talking about pressure testing the coolant system to say, 15-20psi, thats generally not enough to reveal a head gasket leak (unless its really bad).

Did you test your coolant for traces of combustion products? Any coolant smell in exhaust to accompany the smoke?

[Billfitz]

A leak into a combustion chamber probably wouldn't show up in the oil. If you've ruled out all the other possibilities then it's probably the head gasket.

[scottred.f32]

Originally Posted by thejeremyman9

Were you driving hard before all this started the first time? Hate to say, but white smoke in exhaust typically only means one thing... coolant into the combustion chamber. And if you have continued coolant consumption with no leaks, that also points to head gasket, especially if consumption increases as you drive harder.

If you are talking about pressure testing the coolant system to say, 15-20psi, thats generally not enough to reveal a head gasket leak (unless its really bad).

Did you test your coolant for traces of combustion products? Any coolant smell in exhaust to accompany the smoke?

Have not tested coolant and the exhaust does not smell sweet smells like e50.

[thejeremyman9]

Originally Posted by scottred.f32

Have not tested coolant and the exhaust does not smell sweet smells like e50.

You should be able to buy a kit that tests your coolant. That's probably your best next step.

I suppose it could be possible that its your turbo and not your head gasket?

[cfm56d7b]

Although a rare occurrence, N55 turbocharger can exhibit a leak in two places:

- Turbo coolant lines
- Turbo coolant housing can crack - suggest to perform a thorough inspection

Keep us updated!