'76 318 smoke...

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ceekay

ceekay

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So my car blows white smoke quite a bit when cold, but once warmed up the smoke is greatly reduced but is still present. Also, it stinks...

I thought at first maybe a head gasket, but oil and coolant are separate (no signs of crossing at all). Also, if it is burning oil, it is burning a VERY little amount, as I've driven on it for well over a month and just about a tank of gas so far, and there is no change on the dipstick... Literally not 1/32" difference. Also there is no noticeable change in coolant level either...

I've also noticed a faint knock, but it sounds more like an exhaust leak (block side of the manifold because it sounds like only one cylinder, perhaps like a blown mani gasket or something similar)...

Any thoughts? Last thing I need is for this car to blow up on me... :\


Thanks,
- CK
 
valve stem seals
 

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check your spark plugs ......to see if they are oily.

also look at your oil .......after you change the oil is it clean for a long time or dirty right way, any other signs of excessive blow-by, check the PCV valve too, do you smell any gas in the oil?
 
Didn't think of the valve stem seals...

Also, haven't changed oil yet, but need to... Will probably do it this weekend.

As for the plugs, the last ones were fouled with a very thick layer of soot, as is the exhaust pipe (though the exhaust is about 37 years old)...

What exactly am I checking the PCV for, and how?

Not an engine guy.... I can turn a 3ft scrap of rusted steel into a '69 Camaro, but deep engine work alludes me.


- CK
 
One possibility you wont want to hear: You may have a microscopic crack in a cylinder or a head.
When the engine warms up the expansion of the metal may be enough to partially reseal itself. White smoke is coolant, nasty smell is coolant.
Next time the engine is cold remove the radiator cap and bring the engine up to normal operating temperature. Watch the coolant for a very fine bubble or foam.
Check each sparkplug for color variance. Clean/light tan shows optimum performance.
Hope this helps you solve your problem.
 
Damn you're right... I didn't want to hear that! D:

Now I'm sorta hoping the valve stem seals are rotten.... X)

If it stops raining before the end of the work day, I'll try out your guys's suggestions.

[edit] OH I FORGOT TO ASK!!!! Could it have anything at all to do with the exhaust system? Like, is there any possibility from the furthest of circumstances? The pipe is original to the car (i.e. about to fall off), and someone tossed a Cat on it a bunch of years back (cat is still shiny, so it was somewhat recently).... This could also explain why the tailpipe note sounds like two Hondas fighting over the same firing pattern.... [/edit]


Thanks,
- CK
 
It sounds like valve guide seals the way you describe it but could possibly be rings or even something else. If it was me I would do a compression test just to rule the rings out. I'm not sure what test you could do to verify bad valve guide seals. anyone got a suggestion for that?

Another thought is you only drive short distances and there is alot of condensation in your exhaust.:dontknow:
 
I do only drive short distances (a few blocks at a time), but I let her warm up fully before embarking, and it's a desert climate... Still, you could be on to something... I'm tempted to hack the y-pipe section out of the exhaust to see if the Cat isn't being too restrictive or something...


- CK
 
A bad cat would show as a major reduction in power, as in when you step down on it, it would take forever to get up to speed. It would smell like rotten eggs but would not have any smoking symptoms. It can however have a "rattle" also.
 
Valve guide seals and piston ring wear or a cracked piston ring will show blue smoke. Burnt oil doesn't smell good, but it sure doesn't smell nasty.
 
Well, it's not exactly standing up on two wheels when I floor it at a light, and I don't think it smells like a coolant problem... it smells AWFUL (not rotten egg, but very not good, step-pops reckoned to me a while back that burning coolant sorta smells bad but sweet, a la coolant smell)...

I sorta figured it was more a problem with the transmission (needing a rebuild or at the very least a flush or something to make it more responsive), since I really have to play with the brakes in order to get it to brake stand, and half the time I just give up and try to find different pavement... Now I'm REALLY tempted to cut the y-pipe out!


- CK
 
You just made me think of one other thing: A bad vaccuum modulator can weep transmission fluid allowing the trans fluid to be sucked up into the engines intake causing a whitish gray smoke.
 
any idea where this is? I found two vacuum ports (one on the carb, one I forget where but not too far from the carb) that were blocked off with screws.....


- CK
 
I have not worked on Mopar Small Block's or 904 Torque Flights since the seventies but if you check to see if there is a hard vaccuum line with a short piece of rubber hose on both ends, it would be at the back of the carburetor or the back half of the intake down to the transmission. If that hose has trans fluid being pulled through it you will see it the minute you pull one end of those loose.
That said I'm not entirely sure that your trans has a vaccuum modulator.
 
thepaintguy said:
I have not worked on Mopar Small Block's or 904 Torque Flights since the seventies but if you check to see if there is a hard vaccuum line with a short piece of rubber hose on both ends, it would be at the back of the carburetor or the back half of the intake down to the transmission. If that hose has trans fluid being pulled through it you will see it the minute you pull one end of those loose.
That said I'm not entirely sure that your trans has a vaccuum modulator.
Click to expand...

I think that's a chevy thing. My 904 did not have any vacuum modulator.
 
thepaintguy said:
You just made me think of one other thing: A bad vaccuum modulator can weep transmission fluid allowing the trans fluid to be sucked up into the engines intake causing a whitish gray smoke.
Click to expand...

TF trans do not have vacuum modulators.




ceekay said:
I sorta figured it was more a problem with the transmission (needing a rebuild or at the very least a flush or something to make it more responsive), since I really have to play with the brakes in order to get it to brake stand, and half the time I just give up and try to find different pavement... Now I'm REALLY tempted to cut the y-pipe out!

- CK
Click to expand...

The symtoms you describe about the smoke has nothing to do with the trans.



thepaintguy said:
One possibility you wont want to hear: You may have a microscopic crack in a cylinder or a head.
When the engine warms up the expansion of the metal may be enough to partially reseal itself. White smoke is coolant, nasty smell is coolant.
Next time the engine is cold remove the radiator cap and bring the engine up to normal operating temperature. Watch the coolant for a very fine bubble or foam.
Check each sparkplug for color variance. Clean/light tan shows optimum performance.
Hope this helps you solve your problem.
Click to expand...

It would be overheating if this was the case.

It's burning oil from engine wear and very likely hardening seals, and I wouldn't put a buck on the valve guide seals solving it. (Although I am sure it would be part of it.)
As stated above, do a compression test and it will answer your questions.

Also we have to take into account that one mans white smoke is another man blue.
If it smells like burning oil, then theres a darn good chance that it IS oil.
 
Would it be sufficient to just hold my thumb over the spark plug hole to get a go/no-go estimation? My comp tester is 1500 miles away. :S

TrailBeast said:
The symtoms you describe about the smoke has nothing to do with the trans.
Click to expand...
No, but it could be unrelated incidents, or a multitude of problems... Noticed a fairly clunky shift into R, but no real slippage or anything in any of the gears... Definitely a lack of power, though, but originally I just attributed this to the fact that it was an economized 318 ('76, when fuel efficiency was becoming all the rage)... Still, it's pretty sluggish. Really the only way to bust tires loose seems to be heavy acceleration around a corner. She goes, but not nearly as quick as one would think she should, imho...
TrailBeast said:
It would be overheating if this was the case.
Click to expand...
Thank God! Definitely not overheating.

TrailBeast said:
It's burning oil from engine wear and very likely hardening seals, and I wouldn't put a buck on the valve guide seals solving it. (Although I am sure it would be part of it.)
Click to expand...
Anything I should look at for a definite sign, and what should I be looking at for parts? Hopefully nothing too deep into the engine, just for simplicity's sake...
TrailBeast said:
Also we have to take into account that one mans white smoke is another man blue.
If it smells like burning oil, then theres a darn good chance that it IS oil.
Click to expand...
Definitely an ash grey/white smoke, no blue tint to it, though I can double-check this in the morning, just to be absolutely sure.


- CK
 
2 questions?
How many miles on it?
If you let off the gas while driving then get back on it again after about three seconds do you get a cloud out the back when you accelerate again?
 
Unknown mileage. Speedo stopped working a long while back, but the original (as far as I can tell) speedo odometer reads 11180 abouts... Not sure if it's 111k or 211k... It was an old man's pride and joy before I bought it...

As for the cloud of smoke, I'm not sure... Once it warms up, the smoke is almost completely gone; just barely a trace.

Smoke color: Definitely a gray/white, not a blue.


- CK
 
its not using any oil,...its not slightly blueish,...no trail following car round down road,.....and its not using water,...goes away when warm,an down on power in your opinion,gotta jack a corner to ball a tire,.....old raggity exhaust ,..how cold a clement you live??,..lotta humidity,moister?? id guess motor is fine,..its steaming moister outta exhast thats collected while setting,new cars do it to in right weather,...was old mans pride an joy! spect you first to ever ball a tire in the car,he probably babied the ol gurl sine 76,...i wouldn't expect a factory stock 76 318 car to spin less its on dirt...drive it like he did an might last forever,..drive it like a hotrod and itll probably need building soon,....the clunking when you drop it in gear is probably slop in a u-joint or rear end...good luck with ya mopar!
 
Is the white smoke from the exhaust or around the rear wheel wells? Exhaust= BAD. Wheel wells =GOOD! J/K.:burnout:
Are you consuming any oil or coolant? White smoke, like thick steam is generally coolant & will make the exhaust smell down right awful especially with a Catalytic Converter on it. The coolant can enter the combustion process a number of different ways. 1, blown Cylinder Head gaskets or cracked Cylinder Head or Block. 2, leaking Intake Manifold Gaskets. 3, physical damage to the engine itself.
If you're loosing coolant try pressurizing the cylinders 1 by 1 with compressed air & check for bubbles in the radiator neck(cooling system full & bled). Of course you will have to make sure the valves are both closed on the cylinders you are testing. Easiest way I find on Mopars is to remove the whole rocker shaft assembly from the head & then blow the air in. That will close all the valves & you don't have to keep turning the engine over to get on TDC power stroke.
If you suspect it oil burning that's usually bluish smoke. Check your plugs for signs of oil burning. Looks like gray ash or gray with little black spots on the electrodes. Also a overly sooty tail pipe is another sign.
 
How far do you drive this vehicle? Take it for a good 20 minute ride and let the engine and exhaust get hot. Then check to see if you still get white smoke.
 
dirty white boy said:
its not using any oil,...its not slightly blueish,...no trail following car round down road,.....and its not using water,...goes away when warm,an down on power in your opinion,gotta jack a corner to ball a tire,.....old raggity exhaust ,..how cold a clement you live??,..lotta humidity,moister?? id guess motor is fine,..its steaming moister outta exhast thats collected while setting,new cars do it to in right weather,...was old mans pride an joy! spect you first to ever ball a tire in the car,he probably babied the ol gurl sine 76,...i wouldn't expect a factory stock 76 318 car to spin less its on dirt...drive it like he did an might last forever,..drive it like a hotrod and itll probably need building soon,....the clunking when you drop it in gear is probably slop in a u-joint or rear end...good luck with ya mopar!
Click to expand...
Whutdaheyll he say??:dontknow:
 
I'm not losing any fluids, and the smoke almost completely goes away after just 5 minutes of running. Taking it across post (20 or so mins), and the smoke goes away completely.

It would be somewhat of a strange happening if it was vaporizing moisture; I'm in El Paso, TX... Desert climate, though it does get fairly cold here when it feels like it. Still, not a lot of moisture around here (yes it rained a few days ago, but precip is somewhat rare)...

Also, it may have been his pride and joy, but someone tried to be an expert with the poor thing, and ended up screwing up most of what they tried to do to it... It was originally silver, but someone tried to paint it blue, and then someone painted it red. Every time I go to fix something, I see clear evidence of someone's newbie mistake.... Plug wires out of order, overspray all over the trim, tires flipped around (the 215/75R14's on the Left, the 185/70's on the Right), etc. etc. etc...


- CK
 
Condensation. doesn't matter how dry the environment, moisture is a byproduct of combustion.
 
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