tgilligan

Hey Guys,

Need some advice. 1970 Olds Cutlass Supreme with a stock 350 Rocket. Long story short, I'm eyeballs deep into a project list and it's all about the engine work right now.

Changed the plugs today and started her up, she fired right up. Noticed a small amount of bluish smoke coming from the exhaust and soot like stains on the driveway when I bumped the throttle body. Not billowing but still noticeable. After the vehicle warmed up, noticed a very faint amount of smoke/vapor trail coming from the driver's side exhaust manifold area, but could be from the heads, not sure. I'm going to do a compression test tomorrow to see what readings I can get. My ultimate fear is that I need to replace the heads and/or gaskets, ring issues, valve seats, etc. but I'm praying that's not the case as that would sink my budget.

When I replaced the valve cover gaskets, the tops of the heads were virtually spotless and the oil is the right level and the right color. The car was sitting for quite a while as I got the vehicle after a family member passed away. I'm hoping that it's just residual oil that built up from sitting. The old spark plugs I pulled were pretty black and had a faint amount of oil on them. The sides of the exhaust manifold had some old oil on it from the old valve covers that were leaking but while that could explain the faint smoke from inside the engine bay, it's not addressing it from the exhaust pipe.

Carb has been pulled, rebuilt and reinstalled. Valve covers and gaskets are new. PCV is new and replaced snorkle air breather for an open element Edelbrock breather, new vacuum lines, points, condenser, ignition wires. Most of the remaining components are replaced or repaired with the exception of the intake manifold, valves, heads, etc.

Anyone have any idea as to what could be causing the faint bluish smoke?

MDchanic

Loose valve guides / bad valve guide seals.

- Eric

rjohnson442

Sounds normal for any car that sat for a while. How long was the car sitting roughly?

oldcutlass

x2 on being normal for a car that sat for a while, older cars will puff some smoke. While I would not rule out valve guide seals as stated above. The black stuff on the ground is carbon soot build up mixed with moisture from a poor tune or a car not driven for a long enough period of time to burn it out. The oil smoke coming from your engine compartment most likely is from your valve cover or intake manifold.

Make sure your car is tuned correctly with the new parts.

tgilligan

Thanks guys. I'm going to check the timing to make sure I'm at the right advance for this engine and then double check the mixture settings and idle settings of the carb.

For the valves, would the valve seals be the rubber boot under the springs?

edzolz

Back in the day, we would pump the idle up and pour a small can of upper cylinder lube through the carb. That will loosen up the valves and lube the upper rings. Might stop the small amount of blue smoke.

rjohnson442

Did you soak the pistons down with oil Before you started it? And did you prime it before starting?

Lady72nRob71

Right - here they are, springs removed for clarity..

They ride with the valves, deflecting airborn oil away from the guide, hence the descriptor "umbrella seals".
They should be intact and snug on the stems.
I replaced my seals even though nothing was wrong with the ones on there...

Also make sure the oil return holes in the front and rear of the heads are clear. If oil pools up in the valve covers, it could make it to the valve guides. I had that issue as my holes could not even be found! After that work, she burns no oil.

Orlando Perez

were are the oil return holes located??inside the valve covers??

coppercutlass

Oil returns are on the bottom corners of the cyl. head towards the exhaust under the valve cover . You can see them in the picture rob posted.

Rickman48

I had a DD Suburban with 180k on it when it started using more oil.
Stopped at a garage sale and saw an unopened bottle of Slick 50 for $10 - got it for $5 and figured 'what the heck'.
Used high-mileage oil with it - no more oil consumption! Mileage even went up!
Not saying it's a cure, but it worked for me.

Lady72nRob71

Here is my post when I could not find the drain holes in my heads!
https://classicoldsmobile.com/forums...tml#post294407
Locations are made clear down in the thread.

Sampson

X2 to all above. Put a good tune on it and drive it. If it is valve seals you will notice it every morning when you start it up. If it is excess oil from not being driven that has built up in the exhaust and such it will burn off and be less noticeable with time.