White Smoke from Tail Pipe

[Murdul]

About two weeks ago my car overheated due to a broken altenator/power steering belt I didn't notice on the interstate.  Wasn't buried in the red, but pretty close.  I replaced the belt then drove for two weeks and not one issue, I drive 70 miles a day all interstate.  Friday i notice a serious lag in power from 1000 - 2500 rpm and significant amounts of white smoke in my rear view mirror.  I suspect head gasket, cracked head, etc.  I performed a compression test, throttle not down:

1 - 185 psi
2 - 185 psi
3 - 210 psi
4 - 210 psi

My question is why did it take 2 weeks for white smoke to come out of my tailpipe?  Is the over heating not my problem?  Or do I just need to pull the head and let somone tell me whats wrong with it?

Thanks ahead, love this forum I always reference here.

[Geoff]

sometimes, when the head cracks, its a very tiny one at first.   it takes a few heat cycles for it to get big enough to start blowing smoke.    You should remove the head and get it crack tested at a machine shop.   What happens is you dont see how bad it overheats, because once some coolant is lost,  then the temp sensor stops working too.   been there,  cracked that.
                                                                   Geoff

[Murdul]

Thanks Geoff.

My compression numbers look decent.  The first two are more than 10% lower than the other two.  Does this give anyone an idea if the crack is in the first two cylinders, or could it just be wear associated?

EDIT: Forgot to mention there is a very loud clicking sound when the car was running on my way home when I saw the white smoke.

[Warsteiner]

I have also had first hand experience with this....Check the head bolt holes.

Cheers,
~Ralph

[alim_h]

My loud clicking noise was the timing chain flopping around. Not sure how that relates to the white smoke, but for what it's worth.