Oil leaking from spark plug
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Oil leaking from spark plug I'm trying to track down a tick that I think is an exhaust leak (ls1 from an 04 gto). I started pulling the plugs and found that there is oil leaking out of the 2 plug hole (there's also oil on the 6 and 8 threads). All plugs were tight and secure. It was actually a good stream before I wiped over it with my finger. I've done a bunch of searching and can't find the solution. I've read that a little oil on the plug threads is not a huge deal on the Ls1's. Is it as simple as replacing the plugs with a bunch of dielectric grease? Hopefully... Any advice is greatly appreciated.
Make sure the area on the head surrounding the plug hole is clean. The dielectric grease is for the rubber inside of the boot to seal out water and keep the rubber from attaching to the plug.
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Yep what's the mileage on your motor? Unless you have way over 100k on the clock your rings should be good but the valve seals can go much quicker.
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http://www.ngksparkplugs.com/pdf/TB-...1antisieze.pdf
I did it when I swapped plugs, and now I think I may regret it.
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Do a compression test, then squirt a little engine oil in the cylinder in question, now repeat the compression test. If there is a large gain in compression with the oil, than you prob have leaky rings....
Leak down test is a better tool for this though (listen to the crankcase breather, intake, and exhaust for the hissing of air leaking to pinpoint where its leaking)
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Did the compression test, every cylinder was 90 psi except for #6 which was 120 psi. I'm hoping the fact that I was lazy and stupid and did it cold had a serious impact on the results? If not what does this indicate? I'm planning on doing a leak down test in addition to another compression test tomorrow with the engine warm when I have more time.
Last edited by occhevelle; Jun 18, 2012 at 11:23 PM.
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Did the compression test, every cylinder was 90 psi except for #6 which was 120 psi. I'm hoping the fact that I was lazy and stupid and did it cold had a serious impact on the results? If not what does this indicate? I'm planning on doing a leak down test in addition to another compression test tomorrow with the engine warm when I have more time.
I just cannot imagine that much oil coming out of your spark plug hole. The plug would foul and not fire , you would not have compression. Check your valve cover for leaks,possibly dripping and running down the plug wire. Does the car run?
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I'm not sure what to say - I don't see any oil coming from the valve cover or on the plug wires. I just completed dropping the motor and trans (from an 04 gto) into my 67 Chevelle. I'm new to LS1's. I've put a couple hundred miles on it and I thought it ran well. Only problems were when I went to change the oil it was missing a quart or more and a tick on the passenger side. I thought it was an exhaust leak but who knows now.
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Thank you for this post, O.P. I have verified that I have an oil leak out of one of spark plugs on the passenger side of my LT1 Trans Am. Suffice it to say, I am going to have the entire motor replaced with a Jasper remanufactured LT1. I may also be able to work out having them install a mild economy camshaft as they offer it as a part of their "Performance I" package for factory motors. I am happy I don't have to buy a new car, and the cost for this is relatively cheap when comparing.