Plume of White Smoke On Startup....Diagnosis???
 

Hey, in the past couple months or so, I've notcied a plume of white smoke billow out of my exhaust when I start the car up. My first guess would be maybe fried piston rings, and I know that the 305 has never been rebuilt so it's pretty much stock 19 year old parts....could it be something eles? When I took the car out this spring after it had been stored, I also noticed some oil that was burning off my passenger side exhaust manifold, any help would be greatly appreciated

Re: Plume of White Smoke On Startup....Diagnosis???
 

Sounds like a head gasket to me. White smoke usually shows the presence of water/coolant in the combustion chamber.

Valve seals!

What does your oil look like? Is it muddy or clear?

If it's on start up, it's probably the valve seals. That puff is usually a bit bluish rather than white. But it can look white to some people. But that's pretty normal for an aging small block, so no worries yet. You could have new ones installed, or you could switch to Valvoline MaxLife oil. It reconditions your seals, and it'll actually stop or reduce the leaks and the smoke. It really works! :D But you won't notice instant results. It'll go away very gradually over time, 'til one day you'll realize you haven't noticed any smoke in a long time.

I'd guess the oil on the manifold is probably from the valve cover at either the PCV valve or the breather. Check carefully to see if you can find a trail that might've dripped down there. Oil can drip from around the O-ring that the valve plugs into. If so, you might need a new valve and/or O-ring.

But there's always the possibility that it's a head gasket. That smoke would definitely be white, but it would likely happen the entire time your engine is running, not just at start up. If you change your oil and there's coolant in it, then you've got a problem.

But it's probably just the valve seals, so no worries. :)

My engine never used to smoke on startup or hard acceleration, now it chucks out a cloud of blue smoke on startup and some sort of cloud on full throttle (can't tell the colour, only see it against the following cars headlights in rear view mirror, I suspect white though).

The strange thing is it's only started since I installed the adjustable fuel pressure regulator 2 weeks ago and upped the pressure from 43 to 48 psi...

Changed the plugs and they were in perfect condition, just lightly brown.
No mayonaise in the filler cap either (usual sign of coolant ingestion).
Doesn't use a drop of oil but not checked the oil condition yet.

Puzzled...

FocusGhia - If it's doing it all the time like that, you've probably got some pretty worn piston rings and are in need of a rebuild.

One other possibility - Check the oil for some clouding or murkiness. If it's murky then you've probably got a blown head gasket and it's water getting into the oil. Unfortunately antifreeze is murger on crankshaft bearings, so if it's very bad you would need a rebuild because of this too.

CAMAROGUY - I think Fireboyd is right on the money. Sounds like valve seals if it's actually bluish colored and stops right away. If it is truly white, could just be condensation in the exhaust, but not if there is much of it. If it continues for very long, he's also probably right about the head gasket, too. I also tried the MaxLife oil in my 305 before I swapped in my 383 and it did seem to help for me as well. Not eliminate it, but it decreased it.

- Vern

Great, can add that to the new new gearbox I need too... :(

I'll change and check the oil and see what it does then.
I'll also go for another dyno run to see what the car's doing since I mucked with the fuel pressure.

I don't think there's a lot of smoke, I'll look into it over the next week or two...

I'd be surprised if it's anything serious, the car has done 90,000 miles but it's hads a very easy life as it's been owned by a series of pretty old age owners and it's been meticulously looked after and driven carefully (until I got my hands on it 2,000 miles ago...)

I have this too. I'm running excessivley rich as I'm fueling for a blower....but don't have the blower on the car at the moment. I'll be changing my fuel set-up if I can be bothered to stop this. Do you have flames exiting the rear?

on startup? valve seals.

What he said!!!:D

Dunno...

Hopefully! :D

hopefully that is all teh smoke is on acceleration and it's just the valve seals for the startup.

The smoke on heavy acceleration is usually way too much fuel (provided the rings are okay). Blue smoke on startup is almost always valve seals....


- Vern

You mean you can't see the orange glow in the rear view at night? :D

Damn!

I need to do more mods then!

:D