Duramax Diesels Forum Truck of the Week
Old 08-31-2008, 01:43 AM
Philtopgun's Avatar
Philtopgun Philtopgun is offline
Nice n Easy
Join Date: May 2007
Location: Edmond,OK-still a Texan
Posts: 723

Default Egt probe install

Thought I'd try this DIY, EGT PROBE INSTALL.

  • 5/8" open end wrench
  • Standard and Phillips head screwdrivers
  • Needle nose pliers
  • Drill motor
  • 3/16" drill bit(optional-I used as a pilot hole)
  • 7/16" drill bit (only if you using a 1/4" NPT tap)
  • Tap Handle
  • 1/4"NPT tap
  • Heat gun-or flame thrower
  • Heat shrink tubing
  • Anti-seize lube
  • Drill lube-I used wd-40...
1. Yes here in Texas a fan is the first thing to grab and put next to ya. Ha
egt probe install 08-08 001 (Medium).jpg

2. After looking at the clearance behind the passenger fender well to the exhaust manifold, I opted to jack the truck up and take the tire off. Now I dont have to reach over the darn tire and cut threads for my first time. So, grab a jack and jack stand and lift her up.
egt probe install 08-08 002 (Medium).jpg

3. I grabbed a flat head screwdriver and pulled the plastic rivets from the fender well. I could get them partially out from the fender, then I changed to the needle nose pliers and jerked them the rest of way out. Notice there will be other plugs attached from the inside. I just pushed them through with the screwdriver.
egt probe install 08-08 003 (Medium).jpg

4. The fender just comes out easily, showing all the goods.
egt probe install 08-08 004 (Medium).jpg

5. Sorry for the blurry darn pic. When u get close, you can see that the manifold has a small flat spot from the left end to about 2 1/2" out.
egt probe install 08-08 005 (Medium).jpg

6. Just place the bottom of the thermocouple insert within the flat spot and mark her. I did the 2 1/4" measurement and it was right on when I placed the thermocouple insert within the flat spot.
egt probe install 08-08 006 (Medium).jpg

7. I started the truck and then sprayed some wd-40 on the drill bit and on the exhaust manifold. I started out with a 3/16" drill bit for a pilot hole. I started very slow to just draw chips as Ive read from other DIYS and it worked very well. I would draw some shavings and then wipe them off. Then I found out you dont have to wipe them off, because once you drill inside, the exhaust comes out hard enough to wipe her clean with out any assistance! Oh and it sounds pretty cool. The manifold is such a soft metal, you dont have to use hardly any pressure to draw shaving, so just get in a comfortable spot and start slow.
egt probe install 08-08 007 (Medium).jpg

8. Then I changed to the 7/16" drill bit, since I will be using the 1/4" NPT Tap (it recommends the above drill bit). Make sure you dont buy a NC tap when it asks for a NPT tap. Just pay attention and grab whats required by the egt probe you are using. I squirted some wd-40 on the drill and exhaust and just started slow. I stopped midway and checked the drill bit. It was pretty hot so I sprayed her down again and went back at it.
egt probe install 08-08 008 (Medium).jpg

9. I was lost on how to tap this hole. The exhaust was getting to hot to place the tap in the hole and slow start cutting threads, so I turned the engine off. I dont know if this was because I was in my garage and it was 90plus today with poor ventilation(truck was half way in the garage).. After the truck cooled down, I started it back up and went after it. I learned that you dont have to press as hard as you can on the tap. It cuts on its on and you just have to use a sturdy hand to keep the tap perpendicular to the hole. It is very easy to tell when the tap stops turning, just back it about a 1/8 turn and got back at it til it stops and continue the process. After getting a couple grooves in, I would turned the tap all the way back out and clean the grooves. I thought I would get shavings in the groove and start cross cutting. Hey my first time and I did not want to mess up. I cleaned the grooves and very slowly put the tap back in position to start cutting again. Dont jam her in there and start cross cutting. I dont know what you would do if this happens. Anyways its stress free if you take your time. After you gone a ways, take it out and place the thermocouple insert in and check to see if it will sit properly. Once you are able to screw the insert in, take it out and apply the anti seize medicine on the insert and insert it into the manifold. I used a 5/8" open wrench to snug her up. Remember the metal is soft, so dont put any weight behind it when tightening.
egt probe install 08-08 009 (Medium).jpg
egt probe install 08-08 010 (Medium).jpg
11. Attach the probe. I place anti-seize on the probe nut also, but I dont know if I should have done this. My neighbor stopped by bout' that time and said he would... Now you figure out how you want to wire the thermocouple. The thermocouple will have about a 6in" lead on it. I have a Banks box, so I just ran the wire from the box to the probe. Place heat shrink tubing onto the wires to cover the splice between probe wire and the wires from your gauge or box. Heat shrink now, because you will be hiding the wires now to wherever you place them. Some follow the wiring up front, I just used the firewall with zip ties. I dont like the wire being exposed and will have to think of another way to hide this wire. Doesnt look good to me, but will work for now.
egt probe install 08-08 011 (Medium).jpg
egt probe install 08-08 012 (Medium).jpg
egt probe install 08-08 013 (Medium).jpg
12. Ha, now place the fender back in place and try and place all the plastic rivets back with out one being lost. I actually still had each one and got them all in. I even reached inside and placed the other plugs back in place on the fender. First time to not have extra parts or break the little plugs.
egt probe install 08-08 014 (Medium).jpg

Well, I attached the other end of wire to my box that has a lead. I placed the heat shrink over the splice but did not shrink it. I placed black electrical tape on both ends, so I can still take my box off when I need to...

Hope this helps. First DIY, so help a brother out if I missed something or need to add something to make it easier for the next.
2005 GMC 3/4 CC 4x4 SB LLY

Mcrat efi, Banks Ram Air & 4" exhaust, GMax5, MBRP 4" front pipe-cat delete, ADII 165, 3 colbalts n pillar, Shim Mod, SD sleeves, Tony Burkhart steering stabilizer, SD boost manifold, Mike L. Pump Rub Kit, 275/70 bfgs at on stockers now.

1/4= 13.0/104
(Special thanks to Mcrat family, Mike L., 2500HD-Dan-o, Larry Jewell, Alligator Performance, Josh H
still on shelf: passenger race valve,egr blkr

99 gmc 1/2 rc sb 6.0(LQ9),4l80e,efi live
We need a Texas club...

Last edited by Philtopgun; 08-31-2008 at 01:52 AM.
Reply With Quote
Old 08-31-2008, 06:52 AM
LarryJewell's Avatar
LarryJewell LarryJewell is offline
Back with his honey :)

Join Date: Jan 2007
Location: San Angelo
Posts: 11,740


Nice write-up
2004 LLY
Cheetah & MPI Twins
PPE Duel Fuelers

Member # 270

Reply With Quote
Old 08-31-2008, 07:36 AM
Tnsejed420's Avatar
Tnsejed420 Tnsejed420 is offline
Join Date: Jul 2008
Location: Woodland Park, CO
Posts: 31


If the exhaust is getting too hot when tapping you can shut the motor off and use a small magnet with a flex-head to get down in there and pull out any chips from the tap.
06 Chevrolet LBZ ECSB
Pro Comp 7005 wrapped with BFG
SD intake, bilsteins, blocked and fingered, pcv'ed
Reply With Quote
Old 08-31-2008, 08:41 AM
Gmclbz's Avatar
Gmclbz Gmclbz is offline
Join Date: Jul 2008
Posts: 1,048

Originally Posted by LarryJewell View Post
Nice write-up
Reply With Quote
Old 10-05-2012, 10:32 AM
02duramax's Avatar
02duramax 02duramax is offline
Join Date: Nov 2008
Location: Yreka Ca
Posts: 151

Just curious...would the egt temps be different ( passenger vs drivers )?
2003 white cclb duramax, EFI live, 5 inch Mbrp exhaust
Reply With Quote
Old 06-01-2013, 05:05 AM
JTRATX JTRATX is offline
Join Date: Jun 2013
Posts: 1

Nice write up, doing this today on my LB7
Reply With Quote
Old 06-02-2013, 01:01 PM
TLyons90's Avatar
TLyons90 TLyons90 is offline
Join Date: Apr 2013
Location: Greenville, SC
Posts: 1,632


Great write up with pics and info!

Current - 15.5 Denali | Exhaust | Tuned | Lowered | Sleeved | Wheels/Tires
Toys - Honda Grom | To Much To List
Sold - 11 CCLB, 08 ECSB, 07 RCLB, 04.5 CCLB, 04 ECSB
Reply With Quote
Old 06-02-2013, 01:35 PM
714banshee380's Avatar
714banshee380 714banshee380 is offline
Join Date: Dec 2012
Posts: 34

I just did it with the motor off and used a small magnet that fit inside the hole when done to get all the shavings out.
2007.5 LMM 4x4 long bed. Leveled with KMC Enduros and 275/70/18's. 5" Magnaflow turbo back. PCV-reroute. EFI Live via LBZrcks.
Reply With Quote
Old 06-02-2013, 05:04 PM
OregonDMAX's Avatar
OregonDMAX OregonDMAX is online now
Join Date: Apr 2013
Location: Goodyear, AZ
Posts: 3,537


wow, I seriously did this today this morning and then saw this afterwards, at least i knew what to do. but it is a very nice write up indeed.
Moonshine tunes, Mike L trans
Mike L secret squirrel converter
Exergy Sportsman, 4/6 drop, LML 20's/420's
Reply With Quote
Old 09-20-2013, 11:13 PM
MrGrinch MrGrinch is offline
Join Date: Sep 2013
Location: NE Colorado
Posts: 1

Do you have to put this in the passenger side? I just got the full bore driver side manifold and it already has a tapped hole in it for the egt probe. I know the stock drivers side flows about 80% of what the passenger side does, but with the aftermarket one does it matter which side it goes on? Or passenger side cause its further from the turbo is what I've also heard????
Reply With Quote
Old 09-21-2013, 06:22 AM
PhilsLB7's Avatar
PhilsLB7 PhilsLB7 is offline
Way Better Than Facebook
Join Date: Jun 2009
Location: Tennessee
Posts: 810

Sub - Nice write up

02 Chevy 2500HD CC/SB 4X4 LB7 w/Allison Trans
Just stock
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -7. The time now is 06:09 PM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.