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Where / how to install exhaust gas temp sensor in 2003 ISX 525


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I went with ISSPRO for both the Pyromotor (EGT Temp) and a fuel pressure gauge after my FASS pump. I got gauges that look very close to the OEM ones on my dash.

My EGT sensor is on my manifold before my turbo.

i did it myself- new drill bit - new tap - tried to all all drill material out so it didn’t go through the turbo.  I was very nervous- but it all worked out.

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Just a quick tip on drilling the hole for the sensor...  put grease on tip of drill bit, it will keep the metal drill chips from getting inside the manifold an turbo. Do the same when using tap for the threads.

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Drilling and tapping cast iron works best dry.  Grease can make it difficult.  The last thing you want is a broken bit or tap stuck in your manifold.
On the plus side, cast iron doesn't form large chips.  It mostly turns to fine dust, which is quickly swept through the turbo on startup.
It's very unlikely to damage anything, as it will be blown thru before the turbo gets up to speed.

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5 hours ago, Kenster said:

I prefer the thermal couple/sensor approximately 6 in after the turbocharger.

If you put the pyrometer in that location, you need to add about 300° to the temperature you read on the gauge to get the actual exhaust tenp.

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22 hours ago, dl_racing427 said:

Drilling and tapping cast iron works best dry.  Grease can make it difficult.  The last thing you want is a broken bit or tap stuck in your manifold.
On the plus side, cast iron doesn't form large chips.  It mostly turns to fine dust, which is quickly swept through the turbo on startup.
It's very unlikely to damage anything, as it will be blown thru before the turbo gets up to speed.

You can also put a shop vacuum on the hole after drilling and tapping to suck the dust out. 

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I’ve installed several pyrometers, all before the turbo. Some pyrometers can be installed in the manifold right before the turbo, while others have to be further back toward the head, due to the web on some manifolds.

I drill and tap them dry. I then tape a plastic drinking straw to the nozzle of my vacuum, sucking what I can out of the manifold.  The rest, a tiny amount if any, pass through the turbo.  
 

 

IMG_1871.jpeg

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I'm not convinced there is a 300 Degree drop in the EGT while coming through the turbocharger. Has anyone tested this by running twin Pyrometers? As RP once said, "I'm all ears".

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17 hours ago, Kenster said:

I'm not convinced there is a 300 Degree drop in the EGT while coming through the turbocharger. Has anyone tested this by running twin Pyrometers? As RP once said, "I'm all ears".

There is "some" drop in temp, unknown how much, as well as a significant delay in response to changes.
If I'm going to go to the trouble of installing a gauge, I want it to be as responsive and accurate as possible.

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I've never had a thermocouple pre-turbo. I guess it's whatever someone is comfortable installing. Regardless, I would think any pyrometer is better than no parameter at all.

 

 

I prefer the thermal couple/sensor approximately 6 in after the turbocharger.

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Due to the unquestioned principles of thermodynamics, it is impossible for the exhaust temperature to be the same before and after the turbo.  The turbo extracts heat (energy) to power itself.  The temperature AFTER the turbo is dependent on how much boost is developed...HIGH boost=high temperature drop...LOW boost=low temperature drop. You could measure (somehow) the difference in the temps before and after turbo at different RPM and boost pressure, and make a chart...but who can use that quickly enough to know the ACTUAL EGT after the exhaust valves?

Unfortunately, what you are most interested in is the temp exiting the exhaust valves, and there is no way to DIRECTLY measure that unless your thermocouple is in the exhaust manifold.

I'm not sure, but I think some road tractor manufacturers use the after-turbo sensor since the sensor lasts longer at the lower heat AFTER the turbo and they give guidelines on "after turbo" temperatures.  Also, they may be concerned about warranty issues if they drilled into the exhaust manifold.

However, if you want to know the ACTUAL temp exiting the exhaust valves, your sensor must be in the exhaust manifold.

If you are satisfied with a "relative" indication to EGT, after the turbo is fine.

I can tell you from much experience with "chipping" an engine, and reading EGT's, that even a bone-stock ISC can develop 1400*F (in the exhaust manifold) in any number of situations one might encounter under "normal" driving conditions.  If your concern is with lowering EGT, the two primary ways to do so are increased boost (the Gale Banks solution) or higher engine RPM.  There ain't no "free lunch"--if a turbo produces boost, it did so by extracting heat energy from the exhaust gases.

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I ran a snow performance methanol/water injection system on a stock caterpillar in a beaver marquis. It would cool the post Turbo exhaust temperature approximately 150° Fahrenheit when activated.

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I really appreciate all the comments, suggestions, and information you all have offered. At this point I'm thinking to put a sensor after the turbo. I'm not interested in the exact exhaust temp, but rather I'll be monitoring it for any significant change from what I've been seeing in my travels that could indicate a problem. Specifically, I'm looking at something like this: PMD1XT Motor Home Kit - Red - 12 VDC - EGT-DP - 50 FT. Anyone use this one?

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I'm considering the same Kit for my ISM engine. Pre turbo would be a convenient place to put it. The problem is that at lower power settings the temp difference between pre and post turbo is very minimal. However, I'm reading that under heavy load, such as climbing a long mountain incline, the difference can be 300 degrees or more due to energy lost driving the turbo. That's when I want it to be the most accurate.  If it could be demonstrated that a 900 degree post turbo temp was in fact 1200 pre turbo and it was consistent, I could live with that.  

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I would recommend either the Banks pyrometer system or the ISSPRO system. I have used both.  

There are quite a few gauge face and bezel selections with ISSPRO. You can have a red light illuminate at a set temperature. You can also add a gauge adapter, with NO and NC contacts, to turn on a buzzer at a set temperature.

And, I must say ISSPRO tech support was very accommodating with any of my concerns.

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11 hours ago, Venturer said:

I'm considering the same Kit for my ISM engine. Pre turbo would be a convenient place to put it. The problem is that at lower power settings the temp difference between pre and post turbo is very minimal. However, I'm reading that under heavy load, such as climbing a long mountain incline, the difference can be 300 degrees or more due to energy lost driving the turbo. That's when I want it to be the most accurate.  If it could be demonstrated that a 900 degree post turbo temp was in fact 1200 pre turbo and it was consistent, I could live with that.  

Therein lies the problem.  There are so many combinations of throttle position, boost, and engine RPM that you only know the actual EGT when you measure it BEFORE the turbo.  As the OP mentioned, any indication of EGT is better than none.  Again, from my personal experience with measuring and trying to lower EGT, even a bone-stock ISC can develop 1400*F under conditions of high load and low RPM.  I suppose if you installed the sensor AFTER the turbo, you could purposely run the engine at WOT and low RPM and note the EGT, using that as your max allowable temp.

Drilling and tapping the exhaust manifold is not as scary as it sounds.  Just note that many manifolds have a rib in the CENTER at the flange where it joins the turbo.  D&T to either side of it.  Don't ask me how I know, but I have one plugged hole in my manifold.

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11 hours ago, Happycarz said:

I would recommend either the Banks pyrometer system or the ISSPRO system. I have used both.  

There are quite a few gauge face and bezel selections with ISSPRO. You can have a red light illuminate at a set temperature. You can also add a gauge adapter, with NO and NC contacts, to turn on a buzzer at a set temperature.

And, I must say ISSPRO tech support was very accommodating with any of my concerns.

I have an ISSPRO pyrometer and turbo monitor on my F-250.  The actual gauge is an Auto-Meter that I found, which closely matches the Ford gauge cluster.
It works very well.

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