Mystery Oil Leak...

[BigWheel]

Done some well needed repairs and a complete tune up. Car runs like a top but have one minor problem I hope you guys can help with. I have an oil leak that "appears" to be coming from the spark plug closest to the Distributor Cap. No oil anywhere else but coming from the plug hole. I just put on a head gasket set and some valve work. Engine is fairly clean but this one spot. Anybody had this before and give me suggestions?

[bravekozak]

head resurfacing

Did you have your head resurfaced?
Or at least checked for flatness with a straightedge
(or on a CMM coordinate measuring machine)

[piratewilly]

Done some well needed repairs and a complete tune up. Car runs like a top but have one minor problem I hope you guys can help with. I have an oil leak that "appears" to be coming from the spark plug closest to the Distributor Cap. No oil anywhere else but coming from the plug hole. I just put on a head gasket set and some valve work. Engine is fairly clean but this one spot. Anybody had this before and give me suggestions?

OH NO UR SPARK PLUG IS LEAKING, lol jk, it could be the head wasn't completely straight, but check also that ur valve cover gasket isn't the culprit

[BigWheel]

OH NO UR SPARK PLUG IS LEAKING, lol jk,

LOLLOLLOLLOL :laughing6: I first thought it was the valve cover gasket but there is no trace of oil at the gasket. It's strange because it looks like the spark plug is leaking (guess I put too much oil in the plug :p).

[quaddawg]

Still could be valve cover gasket... sometimes the oil "trail" is hard to see, especially when it "pools" in the sparkplug hole.. and burns off the head

[b8kedbeans]

These issues can be super hard to track down... I used cardboard as a barrier to find my leak. The side of the barrier that is wet points toward the leak ;-). You can make a cardboard "washer" that goes over the spark plug and covers the plug hole. Drive the car and then take a peek at where the oil is on the cardboard.

In my case I found out that oil was leaking from the mechanical fuel pump (carbd festy) and it only happened at highway speeds. I never would have found the issue without narrowing it down first.

[piratewilly]

if worse comes to worse, there is a dye you buy that u put in ur oil, and then u get an ultra-violet light and leak should light up bright green. You should be able to get the whole set-up at pepboys, just make sure u clean up the oil that is already there really good first or else u won't be able to tell were its coming from

[jglutz]

If it's running well....I would doubt something other thsn a valve cover leak. Pull the plug and examine if it's dry.

Spray the entire area clean and keep an eye on it...check it after the engine has sat over noght and after it has been driven....continuously check it....the first sign of oil should indicate the source of the leak.

[BigWheel]

Last night I noticed the leak is really bad when the car is running. I still couldn't see the source but oil was bubbling down in the spark plug port running down the engine leaving a good puddle under the car. This points to the valve cover in my opinion. The leak is getting worse. I have done all the updates/repairs with the exception of the head gasket work. I had my mechanic friend do that and I will be talking with him this morning about the valve gasket. I cannot imagine he would not have replaced that before putting the valve cover back on. The car is running great but I have to admit I'm getting a little discouraged. She has been neglected for some time. I knew she needed some work but the more I fix the more the more I find that needs to be fixed. Goes to show that there is only so much you can see on the surface when you buy a car.

Update: Just talked to my buddy and he did replace the valve cover gasket. He said that sometimes the rubber expands when heated and doesn't reseat properly which is why it's getting worse. Since he did the work I'm going to let him take another look at it. I cannot imagine this being the oil sending unit or anything else. Keep your fingers crossed.

[BigWheel]

OH NO UR SPARK PLUG IS LEAKING, lol jk

I wasn't that far off base. I told you guys that I thought oil was coming out of the spark plug port and it in fact was. The head has a small crack at the base of the port that wasn't caught with the compression test. The pressure was forcing the oil up through that crack fouling out the spark plug. Here is how we found the problem. My friend Jeff (mechanic) is the one that pulled the head and sent it to a company here in town for a compression test and milling. The comp test came back good, the head milled/leveled, sealed and put back into place. When I did the tune up last week and replaced the plugs & wires I noticed the first plug was fouled with oil. In addition I noticed that there was more oil saturating the driver side of the engine bay than other places. When I shared this with Jeff it became evident to him there was a problem around that port and he found the crack. So that's the bad news. Here's the good news. The company that performed the compression test guarantees their work so I'm getting a new head and all parts at no cost to me. All I will have to pay for is 1/2 the costs of labor to rebuild everything and that is the help Jeff pay his assistant. Good grief what a day!! Hey...I'll take a leaking spark plug and a guarantee any day .

[Sparky]

Somebody up there likes you, dude! Well, that and a swell guarantee!