smoke on start up: valve seals or piston rings

[Dominick]

i cant remember which causes the smoke. i cant tell what color, but it looks whitish/blue.

[PanamaE30]

If it's white it sounds like coolant leaking into the combustion chamber...

Check the head lately?

[Dominick]

damn i forgot about that. i just got the car and havent been able to rip it open yet.

it also hard to start sometimes when cold. so i changed fuel filter, cap & rotor (havent gotten to plugs and wires yet). but it still does it.

now im thinking its lacking compression, but wouldnt that make it hard to start every time? its starts fine when warm.

i guess its time for compression tests.

But to anser my question, is smoke (from oil burning) on startup from valve seals or piston rings?


Thanks

[Ryan Stewart]

Usually its seals. Iit can drip down. Rings usually cause a blow by.

[macdadmorgan]

yep valve seals, lets oil seap down when the car is off and collects in the chamber, hence the few seconds of smoke on start up.

[Beej '86 325es]

I have the same problem with my M20. I assume from the leaky valve seals it's burning oil on startup, then no more. Oh, I also have white smoke now too because my head gasket is blown. I'm not dropping another dime into that engine until I do the S50 swap.

[Dominick]

yeah mine does it on startup, and now when i pull off at a light. anyone know a way to slow the leaking seals without a head rebuil?

i use that castrol high mileage 10w40 oil, its supposed to help seal old valve seals. but anyone know anything else?

[arnoldgtr]

10W-40 is iffy in Orlando. The temperature range for 10W-40 in an E30 is -20 degrees to 50 degrees F.
Put in some 20W-50.

[Dominick]

alright ill try new oil. im gonna sea foam the engine and then change oil. now im just preparing myself for a head rebuild or look for a fresher one, because its getting worse lately.

i just hope i dont have carbon build up helping the sealing and if i sea foam, it'll get worse.

thanks guys