Reading my spark plugs; Fuel? Oil? Valve Seals? Carb leaking?

Engine, Transmission & Driveline

  1. GG-1

    GG-1 Active Member

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    Hello Dear C-Friends,

    I would be most grateful for your experience & expertise on the subject of reading plugs.
    Please see attached pics of my plugs. You'll see that the ceramic center and electrode-strap all seem to have a good light brown color.. not too rich nor too lean. However, there are two #5 & #7(there are multiple pics of the same ones)which have what looks like oil on the plug threads only.. (maybe unburned fuel?). Also, two or three plugs are darker brown on one side, the side of the gap, is that normal? I pulled these plugs from a cold engine, after several days sitting, so wouldn't any fuel evaporate by then? I've read that unburned fuel on plugs looks black, and oil fouling is a rust color...? A combination of both? I've ruled out valve cover oil leaks. Suspect maybe valve seals..
    despite its 15k original miles, the car is 50 years old.
    The fact that fluid is only on the threads has me stumped. The plugs are not fouled. Air/fuel ratio is good. Timing is good. Air cleaner is new. These plugs have about 900 recent miles in them. The car does not blow out smoke(blue or white) upon cold start.. sometimes a small amount of steam from water evaporation as it comes up to temp.
    I do seem to be losing some oil lately, which is new. I've only driven the car a total of about 1,000 miles since getting her.
    The only thing I can think of is either a couple of bad valve seals, or fuel leaking down from carb. Maybe something totally benign. Thoughts?

    Thanks for taking a look.
    Alex
    IMG_0926.JPG IMG_0927.JPG IMG_0928.JPG IMG_0931.JPG IMG_0932.JPG IMG_0933.JPG IMG_0934.JPG
     
    Last edited: Oct 11, 2018
  2. Wildbunch02

    Wildbunch02 Active Member

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    Might that fluid be oil from a leaky valve cover gasket? Im not a mechanic, so I'm curious myself if that could be your problem.
    The experts will be chiming in soon!
     
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  3. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    Those are normal looking plugs, fluid on the threads is probably from minor leaking from the valve covers, you do not have a valve seal issue as there would be thick crud building up on the electrodes if it was bad enough to cause problems. One side or the other of plugs will show more discoloration due to the combustion dynamics and how waste is discharged from the engine. Drive it.

    Dave
     
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  4. Big_John

    Big_John Illegitimi non carborundum FCBO Gold Member

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    They look good to me.
     
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  5. GG-1

    GG-1 Active Member

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    A few more angle views:
    IMG_0938.JPG IMG_0939.JPG IMG_0940.JPG IMG_0941.JPG IMG_0951.JPG IMG_0952.JPG IMG_0953.JPG

    IMG_0936.JPG
     
  6. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    Re-gap and reinstall. Auto-Lites are not my first choice for plugs as the heat range is not quite right. See if you can locate a set of Champion J11Y plugs as they are correct for most Mopars. Some are for sale and reasonable on E-Bay.

    Dave
     
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  7. GG-1

    GG-1 Active Member

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    I cleaned oil off the threads and reinstalled them.. all gaps were at .035
    Im curious as to how oil can pass through a plug crush washer when it's properly torqued down?
    I'll look for those Champions J11Y
    and see how they go, thanks.
    Will these NOS MOPARS work just as well, or do you suggest Champion specifically?
    NOS MOPAR P34P 8 spark plugs 2642913 Champion J11Y in original packaging. 440 | eBay
     
    Last edited: Oct 11, 2018
  8. GG-1

    GG-1 Active Member

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    Last edited: Oct 15, 2018 at 7:57 PM
  9. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    It is not tight against the plug body, only the mating surface with the head.

    Dave
     
  10. GG-1

    GG-1 Active Member

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    Ok, but there is no sign of valve cover leakage, or signs of oil anywhere on the plug bodies outside of the block. The plugs and block are clean and dry. I still don't understand how oil leaking from valve covers could penetrate where the plugs torque down against the block.
     
    Last edited: Oct 11, 2018
  11. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    This is not something to worry about. Are you burning excessive oil, more than one quart per 1000 miles? Not likely on a 15k engine. Check the torque on the intake bolts for #5 and #7 and run a compression check. If those things are normal, borrow a hydrocarbon tester from your local auto parts and check the coolant for hydrocarbons. This will test the integrity of your heads and head gaskets, just for your piece of mind. I do not see any of that from what I see on your plugs.

    Dave
     
    Last edited: Oct 12, 2018
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  12. GG-1

    GG-1 Active Member

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    Two weeks ago I noticed 1/2 quart loss of oil over 500 miles. So I checked around underneath and found the pan and bolts slick with oil.. no puddles or dripping when parked, not a drop.. but the pan bolts seemed to have loosened up recently with all the sudden activity.. the reawakening of the beast, and definitely needed tightening. I also checked the valve cover bolts and retorqued those down a bit 'til they felt snug enough. Changed the oil and filter & cleaned the oil off of everything. Have not seen it leak since(120 miles or so).
    Bill traintech also suggested checking/torquing down the intake bolts.. will do that soon as well.

    And yes a compression test and hydrocarbon check, for peace of mind, are in order.
     
  13. detmatt

    detmatt Old Man with a Hat FCBO Gold Member

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    You’re a worrier aren’t you?:lol:
     
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  14. GG-1

    GG-1 Active Member

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    Easy for you to say when you know everything.

    Not worried, just insanely interested in learning as much as I can... so I can be just like you.
     
  15. detmatt

    detmatt Old Man with a Hat FCBO Gold Member

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    I’m still learning everyday just like you and I’m miles away from knowing everything. Much closer to being dangerous though!:lol:
     
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  16. rags

    rags Active Member

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    over 30 years in general repairs and every time i walk up to car it's a new experience. ever learn to read ign. patterns on a scope. oil on the plugs came from inside of engine.
     
  17. GG-1

    GG-1 Active Member

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    Thanks Dave, I drive her every chance I get.. except when there is an issue. Then I stop driving her, diagnose.. driving only enough to troubleshoot. I've got a vibrating needle within 1-2 hg on the vacuum gauge(which only steadies at 21hg when idle speed is increased to 850rpm). Also sudden oil consumption of 1/2 quart over the last 500 miles. And the fluid on the plug threads is definitely coming from the inside. Also a rough idle that will not go away no matter what I do to fine tune, and slight shaking that is there at low to mid rpms.. and this still after air/fuel mixture is perfectly set. She's now been driven 1000 miles since June.
     
  18. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

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    Have you run a compression check yet? The miss at idle could be a lot of things, check the timing and be sure your points are properly set. The low vacuum at idle is a concern, but the fact that it comes back at slightly higher rpms suggests that there is probably not a mechanical problem with the valves or rings. Once you have verified that compression is normal and the tune up specs are correct, you should investigate if one or the other of your idle ports on the carb primary has become plugged, that will cause a misfire a low rpms. If you do not have oil leaking from the top side of the engine, check the lower part of the engine, fuel pump gasket, front main seal, rear main seal , timing cover and oil pan. Air flow from the fan tends to blow oil leakage every where so try to clean up the underside as best you can to try and isolate the leak.

    Dave
     
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  19. GG-1

    GG-1 Active Member

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    I'll be doing a compression test later this week and report back with results. The rough idle is slight but there, you hear it and feel it in the engine and exhaust, also steering wheel slightly shaking at red lights and low-medium speeds.. however, there is no miss or dead spot upon acceleration, both part throttle and WOT. I'm with you and also suspect that it may be in the primary idle ports/circuit.. if not that, maybe a tiny vacuum leak somewhere? I'll do a thorough leak search with propane on all hoses and seals with a tach hooked up and watch & listen for rpm increase. Will also check intake and carb bolts for torque. As for vacuum at idle, it is not low at all.. it is running at about 18 hg at 700 rpms, but needle is quickly vibrating between 17-19(1-2 hg in each direction).. only when I increase idle speed to 850 does the needle steady, at about 21hg and higher. Timing is set at 36 degrees total without no detonation/pinging. Dwell is at 28 degrees, within the 28-32 degree range specified.
    Points and condenser are new and gap is on point. I did order a set of NOS Mopar P34P (Champion J11Y) plugs for better heat range. I'll keep checking the underside for oil leaks, but all has been dry since I tightened the pan bolts properly several weeks/200 miles ago.
    Thank you for the suggestions.. will report how things go soon.
     
    Last edited: Oct 15, 2018 at 10:36 PM