WELCOME TO RIVER DAVES PLACE

EGT sensor threads left behind

Chipster27

B Team Member #27
Joined
Dec 21, 2007
Messages
3,555
Reaction score
815
I had an EGT sensor go south on my truck. The sensor was seized in the bung/fitting. I soaked it all week in liquid wrench and this morning hit it with a torch. The nut was loose enough to back out. About 1/2 way out it got tight again so I applied more pressure. It worked loose and came out. I went to thread the new sensor in and it wouldn't bite so I looked at the old one and realized 1/2 the treads are probably in the fitting.

The fitting is in a tight location so my access is limited. What do you recommend to remove the old threads? My guess is it won't take much as they don't have a lot of meat/substance, I just need to get them out.

Here's an image of the nut. You can see there is probably 2-3 revolutions of thread left behind, and they are probably at the first couple threads of the fitting.

ImageUploadedByTapatalk1458432679.197588.jpg
 

Big B Hova

HOSS
Joined
Nov 7, 2014
Messages
4,019
Reaction score
6,773
Id take it to a muffler shop. The good shops have O2 bungs in stock. They can just weld a new one in for you.
 

LargeOrangeFont

Moderation Enthusiast
Staff member
Joined
Sep 4, 2015
Messages
29,944
Reaction score
41,976
Is that piece shown broken? That is not the standard EGT fitting you'd normally see unless that piece threads into a cast manifold.

2 options

1- Chase the threads if the bung is not destroyed. Probably a good chance the bung is ok.

2- Weld or thread in a new bung. Is this bung threaded into a cast manifold or welded into tubing?

If you weld a new bung, the exhaust shop won't have the right bung. You will need to bring it in.

I'm used to seeing fittings and probes like this

image.png
 

COCA COLA COWBOY

Well-Known Member
Joined
Aug 19, 2011
Messages
3,590
Reaction score
2,689
When I drilled/threaded mine, I read to do it while the truck was running. I did as told and never had a problem. Supposedly, the air pressure pushes the remnants out the hole.
 

LargeOrangeFont

Moderation Enthusiast
Staff member
Joined
Sep 4, 2015
Messages
29,944
Reaction score
41,976
When I drilled/threaded mine, I read to do it while the truck was running. I did as told and never had a problem. Supposedly, the air pressure pushes the remnants out the hole.
I did my friend's truck that way too. I'm sure you run a few slivers through the turbo that way, but whatever. It's been fine for over 100k miles.
 

Chipster27

B Team Member #27
Joined
Dec 21, 2007
Messages
3,555
Reaction score
815
Is that piece shown broken? That is not the standard EGT fitting you'd normally see unless that piece threads into a cast manifold.


I'm used to seeing fittings and probes like this
It looked like the ones in your image. I had to cut the top of the probe to get a socket over it as wrenches were starting to round the nut.

Fords have 4 EGT sensors after the turbo. This one was EGT12
ImageUploadedByTapatalk1458440027.836719.jpg

I have a flexible Inspection camera I'm going to put on it tomorrow to see what it looks like. Hopefully I can use a hooked pick to pick the threads out. I thought about tapping it but am worried about cross threading.
 

LargeOrangeFont

Moderation Enthusiast
Staff member
Joined
Sep 4, 2015
Messages
29,944
Reaction score
41,976
Gotcha. I'd gently run a tap through it and see if it cleans out. You will want to at some point anyway to verify the threads aren't buggered, even if you get the material out of the threads.
 

Chipster27

B Team Member #27
Joined
Dec 21, 2007
Messages
3,555
Reaction score
815
Gotcha. I'd gently run a tap through it and see if it cleans out. You will want to at some point anyway to verify the threads aren't buggered, even if you get the material out of the threads.
I'm going to see if I can remove that section of exhaust so I can work on it on a bench, just in case there is a problem. And I agree, probably wouldn't hurt to tap it just to clean up the threads.
 

STV_Keith

Well-Known Member
Joined
Mar 25, 2009
Messages
2,543
Reaction score
970
It should have been 1/4"NPT threads to 1/4" compression, so run the tap through and see what you got. If it's too buggered up, buy a 3/8" NPT to 1/4" compression fitting and enlarge to 3/8"NPT.
 

77 SLEEK

Well-Known Member
Joined
Jul 22, 2011
Messages
232
Reaction score
372
We have had that happen a lot in our shop but found a cool way to remove the fittings. Warm up the bung with your torch then press a tire crayon on the fitting it will melt into the threads and lube it so you have a better chance of removing it. Works really well for us.
 

Chipster27

B Team Member #27
Joined
Dec 21, 2007
Messages
3,555
Reaction score
815
We have had that happen a lot in our shop but found a cool way to remove the fittings. Warm up the bung with your torch then press a tire crayon on the fitting it will melt into the threads and lube it so you have a better chance of removing it. Works really well for us.
That's a great idea! Since there are 4 of these things on here I'll use that trick on the next one :thumbup:

I had also read about mechanics using a butterfly socket/heat/Kroil. Never heard of one so I googled it. Pretty cool tool and much better than an open end wrench.
 
Top