Found my oil leak!

[bigjae46]

I’ve had a relatively minor oil leak I’ve been chasing down. Looks like it’s the freeze plug behind the vanos solenoids. This pic is after cleaning up the engine. You can see a little bit of fresh oil at the bottom.

It was time to do a valve adjustment anyways.

[S54.sueño]

Those can leak??? How does one even replace those?!?

[///Mangler]

'Freeze plug', aren't those for coolant and not oil??

T

[Cubieman]

Nice, I've got an oil leak in the front somewhere other than the Vanos gasket. Oil will build up on the corners of the headgasket where it protrudes sometimes.

It's sure hard to get a good look it that area without removing the vanos solenoid block/pack. I'll have to remove that, clean, reassemble and check at that spot.

[PetrolM3]

This leak is more common than people think but the front plug is fairly cheap and accessible/easy to replace. There are also two of these in the rear of the motor and they are exponentially harder to replace. I think most people have slight sweating/leaking around these plugs (all 3) as you approach higher mileage. Some have serious leaks and end up replacing all kinds of wrong things just to realize this plug is the culprit.

If you look on other forums, you can find instances of catastrophic leaks from these plugs when they literally fall out (due to crankcase pressure). Personally, I chose to use some JB weld on the outside of the plugs as an extra insurance to prevent them from falling out. It can't hurt and it can easily be removed with a pick/screw driver once it's time to replace the plugs again.

PS. The holes which these 'plugs' are in were necessary during block manufacturing at the factory. They have no function/use after the block is machined. I wish the plugs were threaded so we don't have to deal with this.

[bigjae46]

I chose to use some JB weld on the outside of the plugs as an extra insurance to prevent them from falling out. It can't hurt and it can easily be removed with a pick/screw driver once it's time to replace the plugs again.

Interesting, I had a similar thought.

It is common to install a freeze plug in the back of the water pump when deleting the heater core loop. I was concerned with the reliability so I applied some JB weld to the freeze plug. It has held up so far although oil pressure can be higher than coolant system pressure. Ideally, I would have TIG welded the freeze plug in except I could not find an aluminum freeze plug.

I will probably go the same route, rough up the edges and JB weld.

There is also an expansion plug underneath so I am assuming I need to replace the freeze plug AND the expansion plug?

Expansion plug - 11121407412
Freeze plug - 07119901197

[heinzboehmer]

It has held up so far although oil pressure can be higher than coolant system pressure. Ideally, I would have TIG welded the freeze plug in except I could not find an aluminum freeze plug.

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.

There is also an expansion plug underneath so I am assuming I need to replace the freeze plug AND the expansion plug?

Expansion plug - 11121407412
Freeze plug - 07119901197

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.

[PetrolM3]

I would advise against welding - thermal expansion of the motor and plug happens every time the engine heats up and cools down. If you weld that plug (the weld won't be perfectly round and even), it could alter how the plug handles that thermal expansion in the opening and it could leak more than if left alone. If I were to weld, I wouldn't allow the welds to touch the plug, simply put a couple of blobs on the outer end of the opening after installing the plug. JB weld is probably too weak to be able to impact the thermal expansion but it will stay in place and prevent the plug from falling out (mine has been good for over 2 years now). Just my opinion though... I'm no engineer.

Also, how would you weld the rear plugs? I struggled to apply JB weld with my fingers back there due to limited access/visibility (after roughing up and cleaning the surface blindly). Had to use my phone camera on a selfie stick to inspect during each step as there's really no way to see what you're doing. I see no way to weld back there unless the motor is out. And if you do weld, how would you address a leaky plug that's welded - remove the motor?

[bigjae46]

Wasn't planning on welding this one, just talking through my thoughts when I installed a freeze plug on the water pump. On the water pump, I'd just place 4 tacks which wouldn't be enough heat to warp the part anyway.

I'll just rough out of the edge of the opening and freeze plug and apply a little JB weld.

Any advice on removing it? I was thinking about tapping on one edge to push one side in which will pop the other side out and then pry out. Or do I need to remove the VANOS?

[heinzboehmer]

Any advice on removing it? I was thinking about tapping on one edge to push one side in which will pop the other side out and then pry out. Or do I need to remove the VANOS?

Screw a sheet metal screw (or multiple) into it and pull?

[mrgizmo04]

Any advice on removing it? I was thinking about tapping on one edge to push one side in which will pop the other side out and then pry out. Or do I need to remove the VANOS?

Usually use a punch or screwdriver and tap it with a hammer a few times, it will spin and then you can use pliers, or it will pop put by itself. Remember circle is a shape that can not go through itself, so don't worry about it falling inside the engine, unless you mangle it REALLY badly.

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[mrgizmo04]

Screw a sheet metal screw (or multiple) into it and pull?

You don't have much oomph to pull, they are in there pretty well, unless you use those sliding reverse hammers.

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[Tbonem3]

Flush your coolant and just add water back, then drive to the arctic circle, shut the car off and later they should pop out really easily 👌

[bigjae46]

I used a punch and tapped on the bottom edge so the plug rotated on the hole. Then pliers to grab and remove it. Now just waiting for the part to come in.

There is a crusty brown film. I took a scotch pad and cleaned up the opening in the head which also roughs it up for the JB weld. I had this head hot tanked so it is otherwise clean inside. This might be a good thing to do preventively if you take the VANOS solenoid pack off.

I removed the front end so it took 5 minutes. No need to remove the front end, I already had it off for other reasons and it takes me less than 30 minutes to remove.

[Cubieman]

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