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

[GG-1]

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

 

[Wildbunch02]

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!

 

[Davea Lux]

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

 

[Big_John]

They look good to me.

 

[GG-1]

A few more angle views:

 

[Davea Lux]

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

 

[GG-1]

Re-gap and reinstall.

Dave

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

 

[GG-1]

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.

 

[Davea Lux]

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

Dave

 

[GG-1]

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

Dave

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.

 

[Davea Lux]

Ok, but there is no sign of valve cover leaks, or oil anywhere on the plug bodies outside of the head. They are clean and dry.

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

 

[GG-1]

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 one what i see on your plugs.

Dave

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.

 

[detmatt]

You’re a worrier aren’t you?

 

[GG-1]

You’re a worrier aren’t you?

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.

 

[detmatt]

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.

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

 

[rags]

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.

 

[GG-1]

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

Dave

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.

 

[Davea Lux]

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. Also a rough idle that will not go away, 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.

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

 

[GG-1]

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

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.

 

[GG-1]

Hello Everyone- Here's a little update. I did the simplest stuff first, which was check the bolts on the intake manifold, and also the nuts/bolting the carburetor down to the manifold. Some were way to loose, and others not very tight, so I torqued them all down properly. Only now I've got a new issue. I checked vacuum from manifold and was 20hg at 700 rpms with needle on gauge vibrating rapidly staying right on the 20hg mark.
But wait, there's more. I took her for about a 10 mile drive and found the throttle wasn't closing all the way at stop lights. Racing.. could feel it sticking.
I got back and looked at the carb with engine still running, and immediately noticed choke plate closed half way(yes car was up to temp).. and throttle lever wasn't returning closed all the way after acceleration(racing at 1000 rpms).. it is sticking open by only about a millimeter, which I can push closed by hand and it will drop back to correct rpms(700). When I blip the throttle by hand, again, again, it does not return closed, and I can see the choke plate move, closing and sticking in various positions, but not shutting closed all the way. This was not happening before, and the ONLY change I made was tightening carb and intake bolts, being careful not to over tighten. When I moved the choke plate open by hand(with car still running), it was resistant and "notchy", as if it were caught on the steps of the fast idle cam. It was late at this point, so I shut her down. When I returned 5 days later, I first opened the hood, removed the air cleaner, and found the choke plate about 1/4" from being closed. It is usually wide open on a cold engine. I pressed the gas pedal once and the choke plate closed, started the engine, but the choke took an unusually long time to open. I watched it closely the entire time it was opening, and noticed it eventually opening, abruptly in little notchy sections, instead of the usual smooth transition. It eventually opened fully, but the same binding of the throttle and choke plate continued upon acceleration.

Possible causes?
The primary throttle plates are catching at the base of the carb since tightening? Or is some other mechanism catching. Since the throttle and choke and fast idle cam are linked, where should I start to troubleshoot this binding issue. I feel I'm missing something soooo simple. Thanks to all who respond!

Alex