Oil consumption/burning and/or leakage

Tiny
NO984-4-2
  • MEMBER
  • 1970 OLDSMOBILE 442
  • 7.5L
  • V8
  • 2WD
  • MANUAL
  • 115,000 MILES
Had been seeing small amount of blue smoke, and been experiencing apparently a combination of oil consumption and external leakage. Leakage has been corrected, and the oil consumption has been manageable.
A few days ago, I pulled onto a highway and punched it through first and second gears and suddenly a blue cloud appeared from my left tailpipe. There was no noticeable effect on performance, nor change in sound. I nursed my way home over 100+ miles, and went through about 4 quarts of oil, with a large amount of blue smoke, upon acceleration and deceleration but also at idle; still no noticeable effect on performance or sound.
After getting home I looked at the tailpipes and found wet oil inside the left tailpipe. Not just residual soot from burned oil (such as found in the right tailpipe), but actual liquid oil.
Under hood exam revealed that plugs 1 and 3, on left side, electrodes are black and there is oil on the threads, while all other plugs' electrodes are white, also with oil on the threads. Also, ventilation tubes and grommets between the valve covers and air cleaner are oily, and the breather caps/filters in the valve covers are loaded with oil. Can I assume this is normal spray from the valves, or is this indicative of a problem? Should I clean these parts (with gasoline okay?) Once the oil problem is corrected?
I am hoping you can give me possible causes, and how to fix them. Finally, I am asking for your thoughts on whether it would be advisable at the time of the fix to have further work done, given that the engine has never been torn down during 49+ years and 115,000 miles. To reiterate, I don't see any problem with performance.
As I'm sure you've gathered, I am not an accomplished "wrench" just know enough to maybe be dangerous! Thank you very much for any advice you can provide.
Monday, May 27th, 2019 AT 9:57 AM

10 Replies

Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

Very nice car! This could possibly be a few things. I would think that it could probably be a problem with the valve oil seal or it could be a problem with the piston oil rings. A good eay to attack this problem would be to do a compression test, to see where we stand with things. I have included a link below for you to go to:

https://www.2carpros.com/articles/how-to-test-engine-compression

Please go through this guide and get back to us with what you are able to find out. We can go from there, but this is just ruling stuff out. Regardless, we can get this problem fixed, whatever it is, and get it fixed right. Again, very nice car.

Thanks,
Alex
2CarPros
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Monday, May 27th, 2019 AT 10:20 AM
Tiny
NO984-4-2
  • MEMBER
  • 5 POSTS
As I said in my question, there has been no effect on performance. Also, have got no idiot lights. Wouldn't a compression problem cause at least a miss or hesitation, or loss of power?
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Monday, May 27th, 2019 AT 10:37 AM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

Yes, but not necessarily. Really what we are trying to do here is just establish a base line and rule out oil rings. It is the lessor of the two possibilities, but it is only two cylinders that are effected, so it is a possibility. We are just eliminating possibilities, that's all.

Thanks,
Alex
2CarPros
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Monday, May 27th, 2019 AT 11:27 AM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Another thought, remove oil fill cap, engine running, Can you see or feel any smoke/air pressure pulse, that's blow-by, in my opinion. High Crankcase pressure can cause seals and gaskets to start leaking. I agree with wickedstang.
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Monday, May 27th, 2019 AT 11:29 AM
Tiny
NO984-4-2
  • MEMBER
  • 5 POSTS
Thanks, guys. Will get back.
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Monday, May 27th, 2019 AT 12:15 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,513 POSTS
Please let us know what you find. We are interested to see what it is.
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Wednesday, May 29th, 2019 AT 8:32 PM
Tiny
NO984-4-2
  • MEMBER
  • 5 POSTS
Finally got back to my car (sort of) yesterday. Started it up and did JDL's oil filler pipe test, and there was smoke from the oil filler.
An unexpected (to me) thing was that, despite all previous symptoms pointed to a problem on the driver's side, after sitting for about two weeks and having nothing done except removing and replacing the plugs and pcv vent tubes (did not take out he pcv valve), there was only relatively small amount of exhaust smoke and the most surprising development is that most of the smoke was from the right side?
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Monday, June 3rd, 2019 AT 9:10 AM
Tiny
KEN L
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  • 47,513 POSTS
Can you please shoot a quick video with your phone so we can see what's going on? That would be great. You can upload it here with your response.
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Tuesday, June 4th, 2019 AT 10:27 AM
Tiny
NO984-4-2
  • MEMBER
  • 5 POSTS
No; I cannot. You are chatting with a 78-year-old dinosaur, who is trying to survive in today's world with an "antique" flip phone that is usually not on my person and when it is it is usually not on! Anyway, the episode of concern started suddenly, after I floored the 442 through first and second gears, which brought on big cloud of blue smoke from the left tailpipe, and the smoke continued through a 100+ mile trip, billowing thru either acceleration or deceleration, and continuing even at idle. Stopped twice to replenish oil. Now, after sitting for two weeks, starting and idling in the driveway, first at fast idle then at normal idle, a video would show you no dramatic billow of smoke, hardly any from the left tailpipe, where the apparent problem was evidenced before, and now some blue smoke from the right side nothing close to what there was originally from the other side. As I've said, I'm dumb at this stuff, but I have a theory: I didn't take the car out on the road, and didn't even get up to normal driving temperature, so my theory now is that the rings and/or seals don't pass a large volume of oil at "normal" pressure levels, although some, but when there is high pressure and temperature, as when I abused this old classic during my trip and continued at highway speed for an extended time, they failed. I plan to drive the car normally on errands or whatever and see what happens when it heats up. Then, maybe punch it and hold my breath, and see what happens. What do you think of my theory? Does it make any sense? I expect that the car will do fine through the rest of the summer if I don't abuse it. Then, in the fall I think it would be wise to take the car somewhere for their evaluation of whether we need to do a ring job, valve job, or whatever. I'm for putting it off until fall if I can, because it's a convertible and it's convertible weather! Don't drive it much at all in the winter, so if it needs to be "laid up" for a while winter's when to do it.
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Tuesday, June 4th, 2019 AT 1:06 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,513 POSTS
Yep, what you say makes sense the piston rings are worn and the engine needs to be rebuilt. To be sure though we can pull the spark plug for inspection and do a compression test. here is a guide to help, please return with the results:

https://www.2carpros.com/articles/how-to-test-engine-compression

Please run down this guide and report back.

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Wednesday, June 5th, 2019 AT 10:07 AM

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