Smoke from driver's side

[yellomalibu]

I shouldn't even worry about this, since I sold it already, but the new owner has been investigating why the 350 in the Blazer smokes.

At start up, good size cloud of smoke - valve seals - no brainer.

At Idle when up to temperature, the driver's side would smoke enough to be embarrassing to me. He's a local, and has seen how bad it smoked before I put a bottle of lucas in the engine a day before I put it up for sale, which reduced the amount of smoke by more than half!

He pulled the plugs on the driver's side, and said they are a perfect tan color - not oily.

Would the rings cause smoke at idle? I don't know if it smoked while driving (or how bad it did), for obvious reasons. ...and if it is/was the rings, would the plugs be clean and would the lucas help clean it up like it did?

He's looking into replacing the engine because he doesn't want to get into a rebuild... but is trying to troubleshoot it before he does so.

If it matters, it's a 91 TBI motor I put a holley 600 vac sec on, and it had the provisions for a fuel pump in the block. I also changed the cam, timing gears, and oil pump with a HV model... I left the short block alone; it all looked fine when I put it in. It didn't smoke initially, but gradually did, and got worse, as time went on.

What do y'all think? (besides don't worry about it - it's not my problem anymore)

*note* I did tell him that I put the Lucas in it, and even listed on the "for sale" sign that it smokes - full disclosure; I didn't try to hide it from him or the prospective buyers.

[oletrux4evr]

Posi-trac?????
Sorry.....bad joke......

[anotheridiot]

what year was it again? Have a friend that found out his old carburetor was running so rich it was causing the engine to smoke which made it appear to be valve seals. As far as rings though, I would think any part that expands when the motor gets hot would be a cause for cold start smoke, but I would have never thought too rich condition would appear the same way.

[TC]

When was the last time you had a valve cover off on that thing..... This is what it looked like on the last truck I worked on that was around your year..... I had to replace the valve guide seals cause the motor was smoking..... Notice the oil return in the head is plugged closed with sludge..........

[STINEY]

Does it use brake fluid?

I had a Wagoneer that did this until the master cylinder was replaced. It would leak past the seals into the booster while parked, and when first started up the fluid was sucked into the intake and burned making smoke until the fluid was used up.

[milner351]

^^^^^ That looks like the 80's carb'd vehicles I used to work on that were run on pennzoil and quaker state.... yuck.

I'd do a compression check cold with and without a squirt of oil in each cylinder - that would confirm / deny the ring issue.

Sounds like valve seal replacement is in order - and a check of the PCV system.

[SuperBuickGuy]

you're throwing me off with the "all the plugs are a tan color." Is there an oil leak on the driver's side?

[Bamfster]

Does it use brake fluid?

I had a Wagoneer that did this until the master cylinder was replaced. It would leak past the seals into the booster while parked, and when first started up the fluid was sucked into the intake and burned making smoke until the fluid was used up.

Stiney, you're the only other person I've heard of that has seen that too ....

[oletrux4evr]

Stiney, you're the only other person I've heard of that has seen that too ....

Wouldn't that make smoke from both sides?

[STINEY]

You'd think so, but depending on the positioning of the booster vacuum inlet and the flow characteristics of the intake manifold, I suppose certain cylinders would get the majority of the fluid.

My '70 Wagoneer had a '68 Buick 350 for reference.

[TC]

You'd think so, but depending on the positioning of the booster vacuum inlet and the flow characteristics of the intake manifold, I suppose certain cylinders would get the majority of the fluid.

My '70 Wagoneer had a '68 Buick 350 for reference.

You ever see what happens when a vacuum modulator on a transmission takes a crap??.... Put it this way, James Bond doesn't have shit compared to the smoke screen trany fluid will put out.......Thick, Thick, white smoke........ Enough to make a cop car disappear..... Ask me how I know........

[TC]

you're throwing me off with the "all the plugs are a tan color." Is there an oil leak on the driver's side?

That's what got me and why I don't think it's rings and think it's the valve guide seals........

[yellomalibu]

Yeah, I couldn't figure out why it smoked as much as it did and never fouled the plugs. I never pulled them to inspect, but they were the same plugs I installed when I did the engine swap 3 or 4 years ago... autolites that were free.

He's been bending the ears of the guys at the parts store, too, and my buddies at the parts store suggested maybe the mufflers have a bunch of oil in them that doesn't get hot enough to burn off...

The new owner dropped the exhaust and let it run for 15 minutes, and he says there's no smoke. He believes the oily muffler syndrome is the issue.

... I'm not sure if I believe it - but if that's all it is, good for him.

[TC]

Yeah, I couldn't figure out why it smoked as much as it did and never fouled the plugs. I never pulled them to inspect, but they were the same plugs I installed when I did the engine swap 3 or 4 years ago... autolites that were free.

He's been bending the ears of the guys at the parts store, too, and my buddies at the parts store suggested maybe the mufflers have a bunch of oil in them that doesn't get hot enough to burn off...

The new owner dropped the exhaust and let it run for 15 minutes, and he says there's no smoke. He believes the oily muffler syndrome is the issue.

... I'm not sure if I believe it - but if that's all it is, good for him.

When exhaust valve seals leak the oil doesn't get in the cylinder....... That's what was going on with the engine I posted the pic of.......

[yellomalibu]

This engine wasn't super clean, but it didn't look anywhere near what that one you posted the pic of. These heads were clean when I put them on ... remember this is the engine I got for free because all the intake valves were stuck due to varnished gas. I pulled the heads and took them to the machine shop to free up the valves and install new seals. I don't think he did a valve job or knurled the guides, because he only charged me $164... but they were clean.

... but I've been under the impression that the intake valves DO leak into the cylinder when the seals and guides are bad, since the intake pulls vacuum. Perhaps bad exhaust valve seals can send oil into the exhaust... maybe that's what's been going on. ???