EGT probe, pre or post?

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Planning on drilling manifold and placing probe before turbo but keep seeing posts talking about loosing tip of probe and having it go through turbo and ruining it.
Is there anyone out there that has had this actually happen to them?????
Thanks in advance,
Caleb Reese


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1993 LE W250 4x4 CC,Auto,3. 5's,Limited slip. Diamondplate Running boards,toolbox+bedcaps. K+N Filter and gauges on order.
Preparing to B. O. M. B.

 

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The probe will be OK ahead of the turbo. I've had mine there for about 3 years, and each time I read a post about it breaking off & going through the trubo, I pulled it out to have a look. Each time, is was just like new. I just wiped off the soot, and stuck it back in. After about the third time, I started to notice eratic readings, usually low. I ordered a new one, ($50. 00) and found out I broke some wires in the original by messing with it so much. My advice: put it in ahead of the turbo, then LEAVE IT ALONE!... ..... DDG

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Locomotive Engineer/Red Ram Driver! 97,2500,Auto,3:54,2WD,Re-sale Red,Loaded w/Leather, Diamond Tread running boards & box, Bumper guards,"Bull Ring" tie-downs, Front bumper guards, Clearance lights,TST 230 HP kit, K&N, Combo exhaust temp & boost gauge, Eng. & Trans. temp gauges. 3 Pos. Lock up switch.

 

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"Puller", just a note of caution, most EGT probe mfgrs will tell you this, but, don't drill in the center of the exhaust outlet just B4 the turbo. There is a solid baffle in the center that will cause a major problem. Knowing this, just drill either in front of or behind the unseen baffle that runs outward from the engine towards the blower. . Mine is B4 and has worked well for more than 60K miles. .

The B4 installation will give you about 200 - 250 degrees hotter reading than post, because the turbo tends to cool the exhaust stream a bit.

Just use a dab of grease on the end of the drillbit to help collect shavings, and use a small mechanics magnet to remove what falls inside after you tap it out. Good Luck!! FWIT...

Rob. .

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'94 2500SLT, LB, 3. 54, Auto (still original), TST 230 Fuel Plate, K&N Filter, PacBrake, AutoLoc, EGT Gage, DeeZee Chrome Full Length Running Boards, Vent Shades,. Pull 35' HitchHiker 5th Whl (13,850+ lbs) 119,235 miles as of 1-1-00. Full Time RV'ers, Portsmouth, Ohio is "home".

 

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Some info based on installing mine (ISSPRO). Buy an ADJUSTABLE probe!!!! The probe I ordered was fixed length and after looking at it I got worried. I was right, it was too long and would have bottomed out on the the manifold. I took it back to ISSPRO and they exchanged it for an adjustable one (good guys). The only difference was that the compression collar is not pretightened on the adjustable model. I don't know why the dealers sell the fixed length ones to us knowing where it is going to be installed? Next, take the time to drop the turbo. It isn't much of a chore but you will not be able to remove all the drill cuttings unless you do. Just to see what would happen I followed the directions and used grease and a magnet, and then checked to see if any crud was left. Guess what? There was!! Don't take any chances, remove the turbo so that you can see where you are drilling and to make sure you remove all the debris. Finally, invest in a new drill bit before you start. Much easier. Almost forgot, when at ISSPRO, I asked if they had ever had a probe break? The response was that they had never seen a broken tip. BUT, the guy I talked to said that his was installed post-turbo FWIW.

[This message has been edited by DTAUG (edited 01-28-2000). ]

 

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My probe also came pre-compressed. Couldn't fine a new one anywhere in town. Took out my trusty hacksaw and sawed most of the way through the compression nut and inserted the tip of a screw driver and twisted it. The compression ring came right off (and there were no marks on the probe from my activities). Went to Home Dept and for $. 89 I bought a pack of 5 compression rings. I was back in business in about 20 minutes including drive time.

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Rick G - Phoeniz, AZ
99 2500 QC LB 4X4 5-speed
3. 54 LSD
E-brake, ISSPRO Boost & EGT gauges (mounted pre-turbo)
285/75 16 BFG AT KO on AR Atlas
Hadley Air Horns (no more wimpy horns)
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2000 Hitchhiker II 33ft 5er triple slide

 

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FWIW, This topic has been around the CDW and the TDR for ever it seems. As I have not bit the bullet and installed one yet this is an opinion, just an opinion.
I am going downstream, for 1 main reason. When I get off the highway after a long pull I will know for sure when the heat soaked turbo has cooled enough not to cook the oil in the bearings. Once you know how much boost you normally have, you can safely calculate the post turbo red zone. All the heavy highway tractors have them installed post turbo for that reason.

Really if I had infinite money I would go either side, better yet every cylinder. Then you would be able to monitor injector performance per cylinder... .....
Happy Truckin #ad




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Jason's Lil' Mack - 89 D250LE 2WD 5Spd 3. 55 Reg Cab. K&N,"tweaked pump", 3. 5" Exst straight,E&M Custom seats. Bosch H4, HDI Plasma-white HdLites. Bosch 100W Driving. Bosch 55W Fogs.
210,000 miles

 

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FWIW,

I had two EGT gauges on my PSD. I started out pre-turbo, but then wanted to have one post-turbo to monitor cool down of the turbo.

I used the truck for towing, hauling, and just plain running hard. The temp diffential across the turbo was very consistent. Always 250-300 degrees, whether working it hard, or wussing is around town.

I question the reason for TST and some of the other Hi-performance places telling people that the temp differential is inconsistant, and may be as much as 550 degrees.

I am comparing apples with oranges when I talk about my experiance with Ford, and compare what it should be for Dodge. But unless someone has a bright idea why the Dodge would be different, I am gonna assume that the Dodge will be the same.

I will do post turbo for cool down and do the math on the conservative side for EGT.

Thats my . 02 worth

Cheers

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Reformed Powerjoke owner, 2000 model, 3500, Quad-cab, 5 speed, 4. 10, 4X4, straight piped.

NRA member

 

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Mine's post turbo because of the type of probe used with the Auto Meter EGT gauge. You just drill out the hole and the probe is part of a clamp the clamps around the pipe, or in my case, the elbow off the turbo. The clamp supplied is not large enough so I had to put two clamps together to make it all the way around. I don't think it matters which side you put it on, it's your preference. Just remember to allow adequate cool down time and know what the numbers are on the other side of the turbo.

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98. 5 3500 QC 4x4
Driftwood/ Grey Int.
5 spd
PowerMax2, Dual Designs
Ranchhand bumbers, headache rack and toolbox
custom 4" chrome sidepipes, "Scotty Air System", Centerforce Dual Friction clutch, Autometer Guages, DDIII injectors coming soon

 

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The probe is made from steel. The fitting is brass. Brass has a lower melting point then steel and I would think that if the EGTs are high enough to burn your probe then your pistons are toasted.

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1999 2500 Cummins w/4spd auto,Quad Cab,SWB,4x4,Flame red ,all options less leather and radio controls on steering wheel,OEM color matched runningboards,DeeZee bedrails painted black,Power Vision Mirrors,OEM ventshades,Oem sill covers,OEM underrail bedliner