Oil Pressure Sensor Port Cracked

[CODE5]

Well I’ve got myself into a bit of a mess here. I’ve been trying to find a leak for a few weeks now - it’s very small but enough I noticed that it was coming from my oil pressure sensor. When I went to remove it I heard a small pop and the top threaded portion of the oil sending port broke off in my hand…

So I’m at a loss of what to do here. I’m tempted to shave down the existing thread so that the surface is flat again and have the hole tapped — thoughts?

 

[TJ4Jim]

Well you got a bit of an issue there and since it's a pressure port with minimal access there are not a lot of options.

 

[CODE5]

Well you got a bit of an issue there and since it's a pressure port with minimal access there are not a lot of options.

I had a friend look at it, and he mentioned this was a big problem on Subaru's and that their oil pressure sensor units are located on the aluminum head... I'm going to drill out the crack and make a V with the Dremel, then smooth out the remaining port , tap the hole with threads, and install a 1/8 npt male/female extension that I'll thread onto the block so that I can install the oil pressure sending unit and it will work better than what I had in the first place. Here's to hoping that works!

 

[TJ4Jim]

I had a friend look at it, and he mentioned this was a big problem on Subaru's and that their oil pressure sensor units are located on the aluminum head... I'm going to drill out the crack and make a V with the Dremel, then smooth out the remaining port , tap the hole with threads, and install a 1/8 npt male/female extension that I'll thread onto the block so that I can install the oil pressure sending unit and it will work better than what I had in the first place. Here's to hoping that works!

View attachment 417819

How thick is the block casting there.

 

[flyinfish]

Not sure on the oil path there but I'd be worried about any metal fragments or shavings getting in there.

 

[hear]

build it back up with a shitton of weld and re-tap?

 

[Chris]

build it back up with a shitton of weld and re-tap?

That's what I was thinking.

@mrblaine is a good problem solver. I'd love to hear his method / thoughts on fixing this short of a new block.

 

[mrblaine]

That's what I was thinking.

@mrblaine is a good problem solver. I'd love to hear his method / thoughts on fixing this short of a new block.

I'd grind that square to the block down past the V that is broken off until it is flat enough to get a tap started. Tap it for whatever NPT size works and bush it down from there if needed. Welding and building it back up may work, likely a bigger pain in the ass than need be.

 

[CODE5]

Well it took about an hour to get to this stage of cleaning off the block. I’m using some carbide bits for my dremel. It is now sealed and after a 30 min ride around town I’ve got no oil leaking.

However, I hate how it looks. I’d prefer that sending unit thread right up to the block. Is there a better tool for grinding down that metal? It’s tight so a dremel attachment would probably be best. I’m all ears.

 

[KennethS]

A bit of oil and some dirt, then you’ll never notice it.

 

[CharlesHS]

How about a Dremel Flexshaft and the metal grinding bits.

https://www.amazon.com/dp/B0000302Y8/?tag=wranglerorg-20

https://www.amazon.com/dp/B08PVBW9D1/?tag=wranglerorg-20

 

[CODE5]

Yep, I used those bits to remove the lip that was cracked. Took about an hour with them and the speed setting on 15-20

 

[JEEPCJTJ]

A bit of oil and some dirt, then you’ll never notice it.

If that's not a good enough suggestion, try a shorter piece of 1/8 pipe and a coupling both made of steel. And since you've succeeded at previous grinding and tapping and it works, you could build up the now missing casting with JB Weld. It wouldn't have been strong enough to fix the original problem but it will plenty strong enough to make it look more normal.

 

[CODE5]

If that's not a good enough suggestion, try a shorter piece of 1/8 pipe and a coupling both made of steel. And since you've succeeded at previous grinding and tapping and it works, you could build up the now missing casting with JB Weld. It wouldn't have been strong enough to fix the original problem but it will plenty strong enough to make it look more normal.

That’s the plan.

 

[InOmaha]

If it doesn't leak, I'd leave it alone. Since it bugs you, clean the area and hit it with black spray paint so your eye doesn't go to it.

I'd be happy it doesn't leak and just close the hood.

 

[Coachgeo]

I had a friend look at it, and he mentioned this was a big problem on Subaru's and that their oil pressure sensor units are located on the aluminum head... I'm going to drill out the crack and make a V with the Dremel, then smooth out the remaining port , tap the hole with threads, and install a 1/8 npt male/female extension that I'll thread onto the block so that I can install the oil pressure sending unit and it will work better than what I had in the first place. Here's to hoping that works!

View attachment 417819

so the sender is 1/8 NPT?