Found my oil leak!

[bigjae46]

Did this leak cause oil to build up on the protruding edges (corners) of your headgasket?

I've been chasing this for awhile. It dripped off the chain tensioner and then runs down the right (pass) side of the timing cover and then across the right side of the oil pan. I first replaced the chain tensioner crush washer. Then the VANOS gasket. I was thinking it was the timing cover but didn't make sense why it was dripping off the chain tensioner.

[CrookedCommie]

Don't JB weld this. In case you overfill with oil, or get another issue which causes crankshaft pressure to rise, this is meant to relieve it, you'll probably cause more damage if it can't. I've had this fly out on track when the car was overfilled with oil, found it in the underbelly pan, fixed the oil level, and carried on.

[George Hill]

Don't JB weld this. In case you overfill with oil, or get another issue which causes crankshaft pressure to rise, this is meant to relieve it, you'll probably cause more damage if it can't. I've had this fly out on track when the car was overfilled with oil, found it in the underbelly pan, fixed the oil level, and carried on.

I'd be curious to see more info to back this up as I just don't see that as being accurate. The oil separating system is open to the intake, that would have to be plugged to build crankcase pressure enough to blow it out and even then I would think it would have to push past the seals to do that. I would think yours is just coincidence, but I'd be happy to hear more either way.

[CrookedCommie]

I'd be curious to see more info to back this up as I just don't see that as being accurate. The oil separating system is open to the intake, that would have to be plugged to build crankcase pressure enough to blow it out and even then I would think it would have to push past the seals to do that. I would think yours is just coincidence, but I'd be happy to hear more either way.

Another track buddy must have had a similar coincidence, same deal. We fill to halfway now. Either way, not sure that I would jb weld it.

[George Hill]

Another track buddy must have had a similar coincidence, same deal. We fill to halfway now. Either way, not sure that I would jb weld it.

How much was it overfilled? Interesting data points either way.

[CrookedCommie]

At max on dipstick. I'd imagine that the plug serves some purpose, even if it's not this?

[George Hill]

At max on dipstick. I'd imagine that the plug serves some purpose, even if it's not this?

That is definitely not overfilled and not the issue with your plug falling out, I've run dozens of different S54s at that level (and slightly higher if we know it consumes oil and its going to be on track for an extended period of time).

Yes it does serve a purpose, it is to allow access to this oil galley and installation of its plug during the manufacturing process. Knocking in the "freeze plug" is much easier than having to thread and subsequently screw in a plug that would have to have it own shoulder (to set its depth and not just go all the way into the crankcase).

*Note most people refer to these plugs as "freeze plugs" when in fact they are actually core plugs. In this case the plug is to allow access to the oil galley, but I have no idea what the (2) on the rear are allowing access to. In the engine block the plugs are to allow sand to be removed after the casting process is complete. A by product of this design is that they MIGHT fail and prevent a block from cracking, but when I worked in the machine shop we definitely saw cracked blocks with the plugs in tact (clearly a freeze issue, not a mechanical issue). We would "glue" in the new plugs on installation, I can't recall what the product was (its been nearly 20yrs), it's very likely the glue (if these are glued in from the factory) has started to fail on these in the cylinder head and then a pressure spike inside the crankcase pushed them out, but to say this is any kind of "relief valve" I think is incorrect.

[jayjaya29]

There are core plug specific sealants such as this:

https://www.amazon.com/Vibra-TITE-550-Blue-Sealant-Bottle/dp/B004UMP3BK

[bigjae46]

I've run dozens of different S54s at that level (and slightly higher if we know it consumes oil and its going to be on track for an extended period of time).

Side bar...have you noticed elevated oil temps when running near max or a little higher?

[George Hill]

Side bar...have you noticed elevated oil temps when running near max or a little higher?

What do you consider elevated? Honestly though all the cars are generally different enough that I don't think we could make that specific of a correlation.

I will say on our S85 swapped E46 we 100% saw a direct correlation in the oil (and subsequently coolant) temps dropping when switching from LM 10w-60 to RedLine 5w-50 on the street.

[bigjae46]

What do you consider elevated? Honestly though all the cars are generally different enough that I don't think we could make that specific of a correlation.

I will say on our S85 swapped E46 we 100% saw a direct correlation in the oil (and subsequently coolant) temps dropping when switching from LM 10w-60 to RedLine 5w-50 on the street.

Higher than running at half full on the same car.

[stash1]

I wish the plugs were threaded so we don't have to deal with this.

Ya, it’s a bit odd, as high performance engines/blocks (even of yesteryore) would often come from the factory w/threaded ‘freeze’ plugs. If I was building a motor that didn’t have them from the factory…I would always have the machine shop tap the block & install them. It was relatively cheap to do & somewhat std. practice back then—lol

[George Hill]

Higher than running at half full on the same car.

Honestly I don't think we ever knowingly run them off of full, so if they were half full we wouldn't be thinking to check the temp at that specific point. If I think about it maybe I'll try that next time I go to the track, run it half full and then add and see what happens.

[bigjae46]

Honestly I don't think we ever knowingly run them off of full, so if they were half full we wouldn't be thinking to check the temp at that specific point. If I think about it maybe I'll try that next time I go to the track, run it half full and then add and see what happens.

Awhile back I had oil temp issues so I would run at half and it seemed to help. I was mostly curious to get your feedback.

[4getr34]

There's no oil pressure behind that freeze plug. It leads directly into the timing chain area, so it basically just gets splashed with oil. Only thing you need to worry about is crankcase pressure.




The expansion plug is on the surface of the head past the timing chain (further back towards the cabin) and is actually the reason why the freeze plug is there in the first place (access to the expansion plug would be extremely limited otherwise). I'm not sure I would weld the freeze plug in case you ever need access to the expansion plug. Some adhesive like JB weld seems like a decent middle ground.

So, unless you see something obviously wrong with the expansion plug when you take the valve cover off, I would leave it. Freeze plug is the only thing that should be contributing to your leak.

Whats the process for removing the expansion plug?