I'm just wondering where I should install the EGT probe for my BD X Monitor Gauge? I've heard on the downpipe & also on the manifold. Which one is better? and if on the manifold @ what location on the manifold? & will the probe take the heat? It will be installed on a 2000 Excursion. Thanks

 

Hi... I hope I can answer your questions. I installed my ISSPRO EGT probe, pre-turbo. I installed it myself without any problems. I drilled into my exhaust pipe (the downpipe going up to the turbo) about 5 inches from where the downpipe bolts onto the exhaust manifold. I would not drill into the exhaust manifold itself. Doing so would not allow your probe to "see" the aggregate exhaust temp of all four cylinders.

Yes, the probe will handle the temperature. I really like my gauge. I tow a lot and it is really nice to see what the EGTs are.

Good luck! Oh, if you do decide to get the clamp-on model, which is what I have, drill your hole with a very small bit and work up from there. It will help to keep the metal filings very small. I also took a magnet after each time I drilled and passed it along the outside edge of the pipe, hoping to pull some filings out. I did get some.

Steve

 

You can see the clamp on version in my pics.

 

No commercial over-the-road HD diesel has had the exhaust probe installed up-stream of the turbo for over 20-years! If the probe ever cracks from constant heating & cooling, it can break off and go into the turbo with disasterous results to the turbo and possibly the engine. The best place for it is as close to the outlet of the turbo as possible--downstream. The reading just outside the turbo (downstream) will be about 100-degrees cooler than just at the inlet of the turbo. If you go too far downstream you will get cooler and cooler readings. What you realy want to know is the temperature (and thus the size) of the pistons to prevent scoring. In the heavy trucks we always considered 1100-degrees MAX. right outside the turbo outlet. That would equate to 1200-degrees at the turbo exhaust inlet, or about a 1200-degree piston crown temperature.

BobJonesSpecial

 

so where would you install the probe on the down pipe? ie. 2", 3" etc...

 

As I posted yesterday (I think):

 

DCSpecial. So you would install it pre turbo? Where on the manifold would you install it? If you can e-mail me a pic I'd be greatful?

 

Couple of things. One, The thermocouples we buy for our trucks have a housing made of inconel. It is an alloy that is tougher than any metal on your truck. If it were susceptible to constant heating and cooling, every jet powered aircraft on earth would be falling out of the sky. It ain't gonna happen.

Secondly, IF by some miracle the probe did happen to break off, it would only go through the exhaust volute, and may or may not cause any damage to it. There is no concievable way it could enter the engine.

Thirdly (ok three things), the possible 50-450 degree variance posted by DCSpecial between pre and post turbo is exactly right. I don't know where you came up with a 100 degree flat rate, but it's entirely too optimistic to wager a $10K engine on.

If you care enough about your engine to bother finding out how hot is too hot, then the pre turbo installation is the only reasonable course of action.

If you wanted to get the best possible accuracy (and you are really ****) then you shoud drill and tap the manifold about 2" from the exhaust port on each cylinder, and run 8 pyro gauges.

 

I'm not that ****!! Where would be the ideal spot on the manifold for the probe?

 

cookie88........ good post

fhartell,

I've never taken a pic of my probe ( ).....may have to one of these days when I get a chance.


Anyway, Click Here to see a pic of the thermocouple mounted in the exhaust manifold right before it bolts to the up pipe.


And for some more information on this subject, I ran a quick search and came up with that post I was talking about.......Click Here to read it.




Hope this helps

 

Well, the easiest place to mount it is not on the manifold at all, but in the up pipe just aft of where it joins the manifold on the driver side. The clamp on probe is by far the easiest to install. If you are determined to put it in the manifold, then where ever it's easiest for you to get a drill bit on it will work. The manifold is cast iron and may eventually crack around the hole.

 

DCSpecial thanks for the pic link, just wondering if the manifold can be accessed w/ out pulling everything apart & if you think the probe included w/ the BD X Monitor will handle the temps in the manifold?

 

cookie88, do you have a pic of the location?

 

I'll be welding on a bung instead of the clamp on.

 

Type K thermocouple's effective operating range is from 200-2300 F. Your truck cannot get hot enough to hurt it.