HarryD

Hey guys,

History of my car:

• 2002 AP1, 100% stock @ 95k miles
• Drives perfectly, no CEL, no misfires, very smooth and good power
• Purchased used @ 65k miles, valves adjusted, retainers checked for cracks
• Compression test is perfect 225/225/225/225 @ 95k miles
• Billman TCT (not sure what gen), and PCV valve replaced
• Burn ~1 quart every 1-3 thousand miles, depending on how aggressive I am with redlining
• Maintained well (oil changed every 5k miles, brake fluid, clutch fluid, diff fluid, tranny fluid, coolant, spark plugs, IAC valve cleaned, TB cleaned, ECU reset, new PCV valve, etc.)

I daily drive my car, but the smoke happens seemingly randomly every few weeks. While I have always "burned oil" and had to top up, the smoking has only started in the last 2k miles of ownership and I have no idea what is causing it.

Symptoms:

• White/grey/blue-tinted smoke out the back.
• It is not sweet smelling, but smells of something burning. It's NOT water condensation. Coolant levels are rock solid.
• While rare, when it does happen, there is A LOT of smoke. Like forest fire or Cheech-and-Chong smoke.
• The common root cause is if I idle the car a lot (e.g. heavy stop and go traffic in San Francisco, or waiting in line at AutoX runs). Or yesterday the car got briefly rained on (top down), so I idled the car for 30 minutes in my garage with the top up, AC on, heat on to dry the interior. I start the car this morning and instantly I get LOTS of blue smoke out the back.
• Second common cause might be overfilling (to the H line when it's cold). But I've been keeping it on the middle of the HIGH/LOW and the smoke still happens.

I am assuming it might be:

• valve stem seals?
• oil rings?

I've searched countless threads on here and most people with the smoking problem are either on trackdays *or* they are boosted/supercharged (neither of which apply to me). I've also searched DIYs and tend to do my own work, so I appreciate if you can help in as much detail as you can.

Any thoughts on what my problem may be, how to specifically test, and what to fix?

Thanks guys!

windhund116

Do you get more blue smoke out the exhaust on acceleration or deceleration? If it's an accel issue... rings. If it's decel... could be valve seals.

The oil rings maybe seating improperly, at times. I presume you've always used good oil (noticed you changed it every 5K miles). So, prolly not gunk deposited on the rings, themselves. Maybe, play in the cylinder wall clearance and wear in the oil rings causes excessive oil to pass into combustion chamber, at times.




Just a WAG. Good luck with the fix..
.

Slowcrash_101

Take out your coil packs and look in the tubes. If there's oil in there, then the problem is bad tube seals.

Slowcrash_101

Take out your coil packs and look in the tubes. If there's oil in there, then the problem is bad tube seals.

HarryD

I switched from Mobil 1 synthetic to Castrol 10w-30 synthetic--I live in the SF area so heat/cold is not a huge issue. The engine purrs and is quite smooth.

That's the thing. When it does happen, I only get billows/clouds/massive amounts of smoke at IDLE. This has never started during accell/decel or at any speed above 0-2mph. Nothing when accelerating unless the smoke already started when I was idling.

Re: removing coil packs and checking the spark plug holes--they looked pretty clean, no oil.

Thanks guys... Any other ideas/tests?

Slowcrash_101

Valve seals maybe?

windhund116

How about when you use low gear to slow down, on one of those steep declines in SF? Then, at idle, at the bottom --- give it gas. Does it smoke like crazy, then?

If so... prolly valve stem seals.

Slowcrash_101

Sometimes switching oils can clean the engine of certain deposits and sometimes these deposits can wind up in the combustion chambers.

HarryD

Sorry, to clarify, it's probably been on Mobil 1 10w30 form 0-65k miles, and then Castrol 10w30 Syntec from 65k to 95k miles, so the oil brand/type is not a problem.

s2cakeee

Sorry to revive a dead thread, but my 07 s2k is doing the exact same thing, so I was curious if anyone found a solution or has a better explanation. I run Mobil 1 5w30 and was told to switch to Motul. I haven’t tried it yet. I replaced the valve stem seals, but I’m still getting blue smoke after long idles (like in a fast food drive thru). My compression and leak down numbers are good (according to me and two different shops). I am thinking maybe it’s the valve guides, but I daily my car and don’t have the time (or money) to remove the head. I’m honestly ready to just trade it in because I can’t risk having it blow up on me. My commute is 60 miles one way, so I’m afraid my days with my car are numbered