Oil Pressure Sensor Frozen in Block - help

[FJfonda]

My oil pressure sensor rotted, fell apart and spewed oil all over. The remaining piece in the block did not have the original socket shape and attempts to remove it have failed. At this point the piece sticking out of the block is approx 1" in diameter and rounded off. My latest (of many) attempt was to use a basin wrench with a 1/2" drive socket welded to it to grip the remaining piece with no success.. although I did snap the 3/8" shaft on the basin wrench. Drilling it out really isn't something I want to do as it risks getting metal particles in the oiling system. At this point I think I only have 2 options left -- unless someone has other ideas?
- Option #1 - the "safest", carefully tap the hole in the remaining sensor piece Using grease on the tap) and epoxy a screw in to blocking the existing oil pressure port off. Move the sensor to the oil filter pressure test port.
- Option #2 - Weld a nut onto the remaining piece and use that to remove the stub. My concern here is twofold... first is that once heat is applied to this piece it will damage the oring seal pretty much requiring full removal and 2nd concern is that I have already been able to apply a lot of force to this piece without breaking it loose and I am concerned about snapping it off at the block.
Here is my challenge:

Any other ideas?

 

[Joseph Donnelly]

You might try a big "easy out" in the hole.

 

[FJfonda]

You might try a big "easy out" in the hole.

Yeah, thank for the reply...I considered that but the force I have already been able to exert using other methods probably would have snapped the size easy out that would have fit in the hole. I tried an external lug nut easy out device but it threaded over the stub and hit the block, applying force on that situation would have snapped the sender collar.

 

[mwilson]

See if you can borrow one of these, an oil sending unit socket. The edges on yours are not rounded off, it is the way that it is made.

I think that you have enough material left for this to work.

 

[jelag]

I have a thought or two... I'm concerned that the base of the sensor is not steel and you can't weld a nut to it...

I would assume it has loc-tite on the threads as a sealant.... have you tried to heat the sensor... with a propane torch.. I'd guess 300-350* for a couple of minutes.. that's worked for me on some threads...

Like Joe said I'd also try the easy out...

once you have it out.. I'd crank the engine with it out... and let it pump oil and dirt out of the port before I re-installed the new one...

 

[mwilson]

oil pressure sender....

 

[FJfonda]

See if you can borrow one of these, an oil sending unit socket. The edges on yours are not rounded off, it is the way that it is made.

I think that you have enough material left for this to work.

View attachment 87385

I have one of those --- not enough material is left to catch....

 

[FJfonda]

I have a thought or two... I'm concerned that the base of the sensor is not steel and you can't weld a nut to it...

I would assume it has loc-tite on the threads as a sealant.... have you tried to heat the sensor... with a propane torch.. I'd guess 300-350* for a couple of minutes.. that's worked for me on some threads...

Like Joe said I'd also try the easy out...



once you have it out.. I'd crank the engine with it out... and let it pump oil and dirt out of the port before I re-installed the new one...

What is left is steel .. checked with a magnet. I didn't want to heat since it would destroy the 0-ring making my "plug it up" option not an option any more. I plan on the purge method you suggested, also have filled the hole with grease to keep the dirt out while working on it.

 

[FJfonda]

Thanks all for the replies -- mwilson's picture of the sender shows the o-ring... if I am real unlucky and snap off the remaining piece, the access to drill out the piece stuck in the block is real tight. Most likely the shock tower will have to be removed and even then not sure I could get a straight shot at the broken piece.
Chip

 

[Joseph Donnelly]

One piece of good news (potentially) is that the block has straight thread o-ring metric (STORM)threads, so if you you can get it started, it should thread out easily. Maybe a chisel and hammmer near the perimeter to shock it and start it turning would work.

 

[FJfonda]

Thanks, maybe I can break it loose via the shock method. I'm not sure I can get a chisel in position.

 

[mwilson]

Wow, this is indeed unique.

No room to work.

I think my next move would be a decent pair of vice grips clamped straight on, then an adjustable over the handle of the vice grips so that you can exert some rotational force. Maybe a dite of heat before starting to apply force. Farmyard tactics, I know but sometimes that is what a fella' needs to try.

You don't have a lot to lose at this stage.

This is your 2004 shown in the signature, right??? Just want to make sure that you are not dealing with pipe thread as opposed to straight o-ring boss.

 

[FJfonda]

Wow, this is indeed unique.

No room to work.

I think my next move would be a decent pair of vice grips clamped straight on, then an adjustable over the handle of the vice grips so that you can exert some rotational force. Maybe a dite of heat before starting to apply force. Farmyard tactics, I know but sometimes that is what a fella' needs to try.

You don't have a lot to lose at this stage.

This is your 2004 shown in the signature, right??? Just want to make sure that you are not dealing with pipe thread as opposed to straight o-ring boss.

Yeah, it is the 04 .. I am amazed at the corrosion on the engine block and accessories,although the drivers side engine block is much more corroded than the passenger side. Maybe the exhaust heat burns off the moisture on that side.

I tried to get the straight on vice grip technique to work but there is really no swing room for enough leverage. With the modified plumbers basin wrench I had to use extensions to get into the wheel well to swing the breaker bar.

I'm thinking I may take the air hammer and see if I can shock the mating surface of the sensor to block area and retry the basin wrench technique. An idea from a tech here at work was to use a dremel to re establish a hex on the remaining part and use a socket to remove.

 

[JR]

Have you considered an easy out type socket? They are reverse cut, the tighter you crank on them the more they bite, and will grab a perfectly round object. I have a set up to 7/8 and they have saved my arse more times then I can count.

 

[mwilson]

Have you considered an easy out type socket? They are reverse cut, the tighter you crank on them the more they bite, and will grab a perfectly round object. I have a set up to 7/8 and they have saved my arse more times then I can count.

I think he tried that but the hex is so close to the block that the nubs don't contact it.

 

[FJfonda]

Have you considered an easy out type socket? They are reverse cut, the tighter you crank on them the more they bite, and will grab a perfectly round object. I have a set up to 7/8 and they have saved my arse more times then I can count.

JR,
I tried one last night -- the guys at the auto parts store lent me theirs (sold as stripped lugnut removal sockets). The problem I has was as it thread onto the remaining stub it bottomed out against the block behind it. Applying any torque to that would have snapped the top of the remaining sender piece. Good idea though! I was pretty excited last night when they showed me the socket... unfortunately it didn't work.

 

[FJfonda]

Update:
I chose to use the dremel and shape a hex on the remaining piece to accept a 13/16" 6 point socket. Fabricated a cardboard template to match the hex and slowly ground to match a hex shape. After an hour the socket fit perfect..... I was able to sneak my 3/8" impact into the space and the result was rounding the hex back off. Unfortunately I really couldn't find another way to shock it loose..... Time for plan B...
Plan B - plug it up and move the sending unit. ..the hole in the sensor was exactly the drill size for a 10-24 tap. The hole in the sensor is actually almost an inch deep allowing me to use grease and slowly advance the tap without risk of pushing metal particles into the oil galley. Used a shop vac adapted to 1/2" poly to pull any remaining pieces out as well as a healthy engine crank to purge the threads with engine oil. Cleaned things up and used JB Weld to install the 10-24 SS screw into the sensor hole. While that cures I am off to the find parts to adapt a sending unit to the oil filter tap points.
Thanks for all the ideas ... this morning the old farmer I worked for was talking to me (in spirit, he has long passed) telling me there are cows to milk and to stop wasting time. As mwilson said, sometimes you have to use farmyard tactics,

 

[FJfonda]

Up and running. Although there is another oil port on the oil galley 8" in front of the one currently used for the OP switch, based on the corrosion I chose to not disturb it and use the port on the oil filer. Creating the adapter was a bit of a challenge as it needed to be 1/8" FPT to M15x1.5 threads with a relief for the o-ring seal.
Thanks again for the ideas..

 

[richardcoxid]

I am personally dead set against an “easy out” it is true that the tighter you turn it the tighter they grip however, they also expand the broken part tighter into the threads.

I use a set of (I know it sounds weird) LEFT HANDED drill bits! They can be ordered! I have a set in 1/16 inch steps, they are indispensible in a shop! (They are double weird to hand sharpen)

In use the heat of the LH drill bit will help to loosen the broken off piece and as the tightness is relaxed the LH rotation will spin the piece out instead of spinning it in tighter.

Let us know how you come out.