Smoke from one tail pipe but not the other

[DipStick82]

My 1971 C10 has dual exhaust pipe; it has smoke coming out the passenger side but not from the drivers side? Any explanation for this kind of behavior?

Thanks!

[joeydurango]

What color smoke? There's no way it's running on half the cylinders, so there is exhaust coming out both sides (assuming the exhaust is connected all the way back on both sides) if it's running. But if you have, say, blue smoke coming out one side, you're burning oil on a cylinder or some cylinders on that side.

[68is4me]

Does it smoke all the time or just when you 1st start it?

[DipStick82]

It is hard for me to say, but yes i'd say it is a blue smoke. It was a steady stream of smoke after having driven the car for about 10 minutes. There is some oil built up on the that same side of the engine and i've suspected a small leak on that side also... Still trying to diagnose....

[davepl]

If it's bluish, that's usually oil, either ring control or a valve guide. If it's white that's usually coolant, through a head gasket leak.

You've narrowed it down to one bank, now you could likely pull one plug at a time until it goes away (if it does) and narrow it down to a single cylinder. If you do, let us know, I'm curious!

[DipStick82]

So I think it is smoke from Coolant. It doesn't happen till the car is warmed up or at least it increases in quantity the more its driven.

I am suspecting a failed head gasket. I do have a radiator leak, but I don't think the truck is overheating--at least not according to the gauge and it doesn't drive any different. Accept for a sort of un-lubricated moving parts noise that it make while idling in gear. That stops if you put it in neutral.

Is it safe to drive on short trips or do you all think driving it is causing damage to the engine. I plan to take it to a shop soon after I try pulling the plugs as suggested to get more info.

Thanks,
Kelley

[tommys72]

Mine smokes out the drivers side but not the passenger side. It needs valve guide seals. Pass side seals were done but not drivers yet.

[DipStick82]

How did you determine that it needed valve guide seals ? Do you have a photo by chance so I could get a better idea of what we are looking at? This will be my first time replacing them.

Thanks!

[GASoline71]

If it's coolant it will be pale white smoke with no bluish hue to it.

If it's a head gasket also check you water for oil in it, and see if the oil has water in it.

Is this an original 40 year old high mileage engine?

Gary

[ho70]

blue smoke is oil, white is ater related. If you have it from one side and not the other then you can rule out manifold gasket leak, so rings or head. Pull each spark plug separate and see if oil is on them

[DipStick82]

thanks guys any idea what size socket i need for the plugs on this? it is a Goodwrench 350; not the original, but yes high mileage for sure btw

[Grumpy old man]

13/16ths old , 5/8ths new

[DipStick82]

Am I doing damage by driving the truck in the meantime?

[Grumpy old man]

Did you check the oil on the dip stick to see if it's milky or looks like chocolate milk ? And did you check the radiator to see if it has oil in the water ? Either of those would mean park the truck until fixed . Have you pulled the spark plugs to see if any are oil fouled ? How much smoke are you getting out the exhaust ? Post some pictures and save a thousand questions .

[jjzepplin]

You could be damaging it for sure. Do as asked above before continuing.

[DipStick82]

OK, so here is what I found yesterday. I pulled all the plugs on the side that is smoking (will do the other side in the next couple days).

There is no oil in the radiator and no water in the oil from looking in the radiator and inspecting the dipstick.

Plug 5
Was dry & brown at the tip but otherwise ok looking.
Plug 6
Had oil built up below the 'o' ring and oil and corrosion above and below said ring.
Plug 7
Looked a bit corroded and had a dark tip.
Plug 8
Was dark brown to black and had green coolant on the upper threads...

So not the best of news. The plugs also all had larger gaps that I could measure with my feeler gauge.

Advice on what to do next/does this indicate head gasket failure? Was expecting to find oil or coolant in there, but not both...

Thanks!
K

[Grumpy old man]

The cylinders are #1 front drivers side #2 front passengers side

1357 all on drivers side

2468 all on passengers side


Firing order 18436572

So which side did you pull ?

[Gromit]

If it is an automatic transmission, it could also be a blown modulator valve diaphragm allowing trans fluid into the vacuum circuit through the manifold and depending where you have the vacuum line to the modulator connected and what type of manifold you have the trans fluid can sometimes get pulled into one bank of cylinders..

[DipStick82]

Grumpy, I pulled 2468.

Gromit, what makes you suspect the modular valve diaphram? I noticed coolant and oil on the plugs but didn't see any trans fluid. Did something else I mention make you suspicious or is this just another thing to check...

[Grumpy old man]

Originally Posted by DipStick82

Grumpy, I pulled 2468.

Gromit, what makes you suspect the modular valve diaphram? I noticed coolant and oil on the plugs but didn't see any trans fluid. Did something else I mention make you suspicious or is this just another thing to check...

It's just one more reason for smoke . You can crawl under the truck on the passengers side and see the modulator valve on the trans with a small rubber hose going to a steel tubing ,there shouldn't be any trans fluid inside the hose .if it's dry

Change all the plugs gapped correctly at the same time , toss in some bars leaks head gasket seal ($24.00 at Wal-Mart ) and see if it clears up . This isn't a permanent fix but will give you a better idea of the repair your facing ,head gasket vs worn seals. Replacing head gaskets and having the heads serviced while off is the correct fix .

[DipStick82]

I will change the plugs. This is a Goodwrench 350 crate; any recommendations on what plugs to use? The ones I pulled were the Autolite 86.

[Grumpy old man]

Just get another set of the autolites , post a few pictures of your engine . And find a local truck club they can help you with many of these type issues .

[DipStick82]

Ok got another set of Autolites on the way and have attached some photos to this post; dirty fuel & air filter have since been replaced. I included the oil fouled spark plug. Does this sound to you guys like a park it until fixed scenario ?

[Gromit]

Sorry I just read where you asked me a question - I thought of the modulator valve only because it was passenger side only smoke.

But if you found coolant on the cylinder side of a spark plug that makes the head gasket seem the source of the issue.

I wouldn't ignore the sound you mentioned coming from the trans though.

I would be curious to know if the head bolts torque were still at their tightening specification on that passenger side head - but even if they are not, I think that once the head has been leaking it is probably not okay to just tighten them; in other words probably need to replace the gaskets.

[Grumpy old man]

The picture of the spark plug is NOT oil fouled ,you have a leaking valve cover gasket and the oil you see on top of the plug is from the leak. Look at the end at the electrode and that cylinder is burning good . What # plug had anti freeze ? I'll bet it was #2 because you have a leaking thermostat housing (notice the leak stains ) and your top radiator hose is ballooning and probably soft , replace it along with the thermostat and gasket along with the valve cover gaskets . Again replace the plugs and try the bars leaks , your engine needs some basic general maintenance by the looks of the pictures . When's the last time you changed the oil ? And get rid of that glass gas filter before the whole mess goes up in flames ! They are the worst filter to use on your truck ! Buy a METAL filter .looking at the picture again the rubber fuel line you have coming from the fuel pump to the carb looks awful close to the exhaust manifold . With what I'm seeing I'll bet a donut you need valve seals and not a head gasket .