Blue smoke @ ignition

[jode]

My 73 360 blows a nice cloud of blue smoke at ignition (it goes away immediately).
Is this a symptom of something in specific or a sign of many problems?

[joe]

Your valve guide seals are leaking and the guides are prolly worn also.

[jode]

Rebuild?....or replace seals?

[Crazy_Jeepman]

Depends on the miles on your engine. If a high mileage engine I would just change the valve guide seals, or else a complete rebuild. Depends on what you want. If heads need Valve guide work, this generally means the engine will have other issues as well. ;)

[joe]

Well you could try just replacing the seals...they're cheap. Odds are you need to remove the old guides though and press in new ones if you're running a high mileage motor. I'm sure they're worn at say 100,000 miles?
A little blue smoke at start up is pretty normal for an old motor and doesn't really hurt anything. I DO NOT recommend rebuilding the entire head(valves etc) on a high mileage motor w/o doing the rest of the motor. Good chance the new found compression at the upper end will blow out the oil rings and then you'll be blowing blue all the time...BTDT.
If it's just puffin at start up I'd leave it alone till you get ready to rebuild the entire motor. Won't hurt nothin...other than the shame factor if you're parked next to some greenies ;)

[jode]

<blockquote>quote:</font><hr>Originally posted by Crazy_Jeepman:
Depends on the miles on your engine. If a high mileage engine I would just change the valve guide seals, or else a complete rebuild. Depends on what you want. If heads need Valve guide work, this generally means the engine will have other issues as well. ;) <hr></blockquote>

High mileage = yes
Other engine issues = prolly
It currently has a bit of a click (may be exhaust manifold leak - maybe a lifter knock..I dunno) coming from it...seems to have decent power (once warmed up)
What I want is for it to run decent...and not to fog the neighbors when it starts :D

[jode]

Ok ...thanks Joe

[joe]

"Some" blue smoke at start up is one thing...if it's foggin out the neighbors...on an engine with 100,000+ miles...an entire eng rebuild may be in your near future. If the heads are that far gone odds are the bottom end may be too at 100,000+. I'd start with a dry/wet comp check and see where you're at on the general condition of the motor and plan from there.

[Bob Barry]

Another thought... If your oil drainback holes in the corners of the heads are clogged with coked-on oil, the oil will collect under the rocker cover and gradually seep into the cylinders when you shut it down (no matter how good your guides and seals are), and when you start it up, it ALL burns off at once.

This was the problem my Cherokee had when I first got it. If the smoke-show clears up after a few minutes, your seals may be fine. It'll only take a pair of new rocker-cover gaskets to check it out, and a coat-hanger to clean the passage out (change the oil afterwards, though). Once I cleared the passages, the smoking on startup was gone. :D

Realize, however, that if the engine was neglected enough to clog the oil-passages, it's usually a sign that everything else is likely to suffer an early death. :eek:

[ May 14, 2002: Message edited by: Bob Barry ]</p>