Thats right. The engine started having a slight sputter to it so I looked at the spark plugs and all of them are fine except for spark plug 3. Covered in oil. Im assuming the is a gasket issue? Its a 91 corolla 1.e6. I can never remember if its afe or age. Its not the sporty car.
More likely a valve seal. They harden over time and will leak through the valve guide.
Take a compression tester, and pull the schrader valve out of it, and disconnect the gauge from it. This leaves you with a hose that threads into the spark plug hole and has a air line connection on the other end. You can then hook this up to an air compressor and pressurize up the cylinder continuously. By doing this you can use an overhead cam spring compressor and remove the spring/retainer and access the valve seal without pulling the head.
Yah the cams need to come out.
If its a 4afe motor you need to put a bolt in a hole on the intake cam to keep tension on the retentioner gear thingy before you pull the cams. Ill see if i have a picture if you need more direction.
A compression test is looking for a bad ring, leaking valves, blown head gasket, etc. and your #3 reading seems fine. Just to confirm, it's the cylinder side of the plug that's covered in oil right? Because if the plug is in a tube, there can be a leak which gets enough oil in the tube to cause a problem.
Your compression test would tell you if there is a major compression problem, a leakdown test would tell you where the problem comes from. Your compression test came up fine, therefore I don't see it being an HG or Ring. The only other options are valve cover gaskets or valve seals. A valve cover gasket would show up as a ton of oil leaking down the spark plug bore, which I'm assuming isn't the case otherwise you would have took notice. Valve seals harden over time and stop sealing, happens to every engine. The seals themselves are dirt cheap, probably 30-40 bucks a set for the whole engine, it just takes a bit of labor to replace.
If you haven't used a spring compressor try searching youtube I'm sure there are videos of them there.
Yes it was the cylinder thats covered in oil, along with the tool I used to get it out. I'm assuming oil had collected in the spark plug hole before I took it out.
I guess the question is was your spark socket and plug wire boot covered in oil? You mentioned your car was sputtering, which can be due oil fouling of the plug or arcing between the spark plug wire and the plug itself due to oil being the "tube".
The boot didnt have oil on it. But the tool did after i pulled it out. I didn't look down in the hole before I put the tool in to get the spark plug out so I don't know if there was oil in it to start with. I don't think so because the top half of the spark plug, the half that is basically inside the tool, was no covered in oil. Just the bottom half and the tool after I pulled it all out.
I think you're confusing the cylinder with the tube. The cylinder is where the piston and valves are (altho the valve stems come up thru the head) and the cylinder side of the spark plug is the threaded part with the insulator tip and electrode(s). The other end of the plug has a seal/washer, the 'nut' which is used to install/remove the plug with a socket or appropriate tool, the insulator (which is often ribbed) and the terminal to which the plug wire boot is attached. When you remove the plug wire if you were to look down into the tube you would see this part. It sounds as if this is the part which has oil on it. If so, your tube is leaking. This makes sense with your compression readings. The oil in the tube can cause the plug to 'short' out even if it isn't very deep. This will cause a 'sputter'. If this is your problem then you will need to replace the tube seals. I believe the tube is pressed into the head with some sort of seal which some may be referring to as a valve seal. (I don't know and I'm not a mechanic but I have rebuilt engines in my younger days and valve seals were around the valve stems and would not cause a leak in a tube. Not that the engines I built had tubes anyway. ) There should be a seal at the top of the tube as well where the nut holds down the valve cover. Search "spark plug tube seal" or similar both here and the internet. There is a lot of advice and youtube videos on how to do these. I just removed the nuts holding the top tube seals and valve cover down, pried off the old seals and installed new ones. You can buy these separately at most parts stores. You can get the valve cover gasket with new tube seals and replace it too if you want. But if it's the bottom of the tube which is leaking then apparently that's a real PITA. Hope this helps and good luck.
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) There should be a seal at the top of the tube as well where the nut holds down the valve cover. Search "spark plug tube seal" or similar both here and the internet. There is a lot of advice and youtube videos on how to do these. I just removed the nuts holding the top tube seals and valve cover down, pried off the old seals and installed new ones. You can buy these separately at most parts stores. You can get the valve cover gasket with new tube seals and replace it too if you want. But if it's the bottom of the tube which is leaking then apparently that's a real PITA. Hope this helps and good luck.
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