[C1] Oil on plug threads
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,102
Likes: 171
From: Colorado Springs, CO
Oil on plug threads
I’ve noticed some oil on the threads of my #2 spark plug when cold. When hot, I checked the plug immediately after shutdown, and it was dry and looked fine. This is on my 57 with a 350 and dual wcfbs. Is this oil leaking past the valve seals and accumulating overnight, or what? I checked valve cover, and it is not leaking. I do have a pcv setup, and engine uses no oil, and doesn’t smoke. Any thoughts? Other plugs look fine.
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,102
Likes: 171
From: Colorado Springs, CO
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,102
Likes: 171
From: Colorado Springs, CO
Burning Brakes
Joined: Apr 2020
Posts: 962
Likes: 357
I’ve noticed some oil on the threads of my #2 spark plug when cold. When hot, I checked the plug immediately after shutdown, and it was dry and looked fine. This is on my 57 with a 350 and dual wcfbs. Is this oil leaking past the valve seals and accumulating overnight, or what? I checked valve cover, and it is not leaking. I do have a pcv setup, and engine uses no oil, and doesn’t smoke. Any thoughts? Other plugs look fine.
I fought a problem like this for 4 years and in the end solved the problem with $1.50C worth of thread sealer.
Are you listening Pete220?
Eddie
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I had this situation as well. In my case, no blue smoke either.. No noticable smoke at all.
I run synthetic oil, and I understand it's smoke is 'clear', not blue when it burns.
It was oil leaking in as Dan suggested above. I installed a set of umbrella-style valve seals and it improved greatly.
Fred
I run synthetic oil, and I understand it's smoke is 'clear', not blue when it burns.
It was oil leaking in as Dan suggested above. I installed a set of umbrella-style valve seals and it improved greatly.
Fred
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Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,102
Likes: 171
From: Colorado Springs, CO
Here’s a couple pics of what plug look like cold. As I said, when pulled hot it is clean of any oil, although it is somewhat black from running rich and I suppose burning off the oil? Probably the valve seals as mentioned, so I may wait to see if things worsen. Thanks for the responses.
John
Thread Starter
Burning Brakes
Joined: Mar 2006
Posts: 1,102
Likes: 171
From: Colorado Springs, CO
Update-
Well, after reading Drummer Boy’s thread, I did more investigating. No, I don’t have aluminum heads, but I did have oil wicking up around the intake bolt on driver’s side, above cylinder #1. Pulled bolt, cleaned it and applied a liberal amount of thread sealer, and leak issue is gone, plus plug is staying dry! I don’t fully understand the whys of this, but issue appears to be resolved. Maybe oil leak at manifold created enough of a vacuum leak to cause this? Also, I noticed that I didn’t have gas dripping from my carb pump nozzles after a hot shutdown. Coincidence? Who cares! Thanks again for all the advice.
John
Well, after reading Drummer Boy’s thread, I did more investigating. No, I don’t have aluminum heads, but I did have oil wicking up around the intake bolt on driver’s side, above cylinder #1. Pulled bolt, cleaned it and applied a liberal amount of thread sealer, and leak issue is gone, plus plug is staying dry! I don’t fully understand the whys of this, but issue appears to be resolved. Maybe oil leak at manifold created enough of a vacuum leak to cause this? Also, I noticed that I didn’t have gas dripping from my carb pump nozzles after a hot shutdown. Coincidence? Who cares! Thanks again for all the advice.
John
Burning Brakes
Joined: Apr 2020
Posts: 962
Likes: 357
Update-
Well, after reading Drummer Boy’s thread, I did more investigating. No, I don’t have aluminum heads, but I did have oil wicking up around the intake bolt on driver’s side, above cylinder #1. Pulled bolt, cleaned it and applied a liberal amount of thread sealer, and leak issue is gone, plus plug is staying dry! I don’t fully understand the whys of this, but issue appears to be resolved. Maybe oil leak at manifold created enough of a vacuum leak to cause this? Also, I noticed that I didn’t have gas dripping from my carb pump nozzles after a hot shutdown. Coincidence? Who cares! Thanks again for all the advice.
John
Well, after reading Drummer Boy’s thread, I did more investigating. No, I don’t have aluminum heads, but I did have oil wicking up around the intake bolt on driver’s side, above cylinder #1. Pulled bolt, cleaned it and applied a liberal amount of thread sealer, and leak issue is gone, plus plug is staying dry! I don’t fully understand the whys of this, but issue appears to be resolved. Maybe oil leak at manifold created enough of a vacuum leak to cause this? Also, I noticed that I didn’t have gas dripping from my carb pump nozzles after a hot shutdown. Coincidence? Who cares! Thanks again for all the advice.
John
In my case, each time "A" piston went down on the intake stroke, the vacuum it created simply sucked oil from rocker arms, down passed the threads and into the intake stream. It was literally RAINING OIL inside every cyl.
Make certain to seal every one of those studs.
Happy Driving.
Eddie