EGT probe location

Hello all,

Looking to install an EGT probe.

I have blocked the EGR but left the pipe in place. I was thinking perhaps to remove the pipe and mount the probe on the top blocking plate, would that be a good place?

Searching the forums it seems some people install the probe after the turbo. Is that a better location, if so can someone explain why?

Thanks

Hi mate it's all about the accuracy of the point of measure. The best place is the exhaust manifold, but you would need to remove it before drilling. The dump pipe is the next best choice some of the quality exhaust manufacturers have a point where a probe can mount.

I have a td27 and i think the exhaust are majority same design.

I took the egr pipe and removed it and installed my EGT bung.
This is not a bad location but it needs to be in the exhaust flow.
some egrs are sort of out of the location of direct exhaust flow.

either location is fine. (inside exht mani / after turbo)

there is different EGT temp ranges for the different locations. (internal is higher / external is lower)

installing it in the exhaust dump pipe is usually easier to do.

inside the exhaust manaqfold there is pressure, usually equal to the boost being run...so you need to make sure you have a perfect seal otherwise exh gass will leak out.

after the dump there is no pressure, just flow, so you dont need to put up as much effort to avert pressure loss.

way old thread and post, but its still the same
http://www.navara.asia/showpost.php?p=105215&postcount=36

i removed half my egr pipe and fitted the probe into the blanking plate on the exhaust manifold (D40). i get a reading of 300-400 at 100-110kph.

Mines in the blank plate I made right in the path of number 4 cylinder

Hatchy said:

Mines in the blank plate I made right in the path of number 4 cylinder

Click to expand...

That's exactly where mine is too. There's a pic in my garage.

Mines in the EGR plate too. just drill a hole in the plate and welded a nut over it for the probe to screw into.

I made my blank with 10mm plate then tapped it out. Works mint 110kms I get around 350deg

Thanks everyone for your replies. Seems the blanking plate is the way to go. Just to be 100% sure we are talking about the top plate, right? Not the lower one..

We're talking about the egr port at the rear of the exhaust manifold. You have to completely remove the egr pipe and make a plate to go over the port which is solid enough to weld a nut or tap a thread to accept the thermocouple probe. And then also block the egr port on the inlet side.

slepax said:

Thanks everyone for your replies. Seems the blanking plate is the way to go. Just to be 100% sure we are talking about the top plate, right? Not the lower one..

Click to expand...

Your probably looking at the pipe from the EGR valve itself to the intake manifold. There's another pipe that goes from the back of the exhaust manifold (next to the turbo) around behind the engine to the EGR valve. We remove that pipe and put a plate on the end of the exhaust manifold and tap it for the EGT probe.

^^ I've got a probe there which is connected to a digital gauge (Autron) with alarm.
I've got a second probe in the dump pipe (3" exhaust) connected to a gauge on a pillar pod.
I can monitor pre and post turbo temps. It can be up to 200C difference between the two (hotter pre-turbo) but generally runs around 120-130 hotter.

Being cautious, I run my alarm to kick in at 550C so I don't run the engine too hot, but I've heard of guys running a lot hotter.

1310/71 said:

^^ I've got a probe there which is connected to a digital gauge (Autron) with alarm.
I've got a second probe in the dump pipe (3" exhaust) connected to a gauge on a pillar pod.
I can monitor pre and post turbo temps. It can be up to 200C difference between the two (hotter pre-turbo) but generally runs around 120-130 hotter.

Being cautious, I run my alarm to kick in at 550C so I don't run the engine too hot, but I've heard of guys running a lot hotter.

Click to expand...

The general rule used to be 550c post turbo, but as you have found, the pre turbo temps can be up around 750c by then when pushing very hard. There's nothing wrong with keeping it around there though, at least you know you have a bit up your sleeve if you really need it.

That was the plan Bods, in case I get stuck towing up a hill or something and can't do much about it.
Just freaks me out a bit when the buzzer first goes off without warning (if I haven't been watching the gauges) but again, that's why it's there. I chose the quietest buzzer I could find in Jaycar but it still startles you at first, then gets annoying if it lasts too long. I can't recall what my trip out setting is, I think 500 (ie it needs to cool down to 500C before the buzzer stops). I could probably put some tape over it or something but for the few times it goes off, it's not worth it.

Haha. I haven't got one of the auber ones on mine, but I have heard that about the buzzers. Like you said though, it is there to get your attention. I have my probe in the fump pipe probably 50mm from the turbo outlet and haven't got it too high yet, but haven't done any decent hills yet either. My gauge is in Fahrenheit though, so I just keep it below 1000f, which is about 530c... the most I've seen it is around 800f, but I don't tow very often either, so up a decent hill with a bit of weight behind it I'd expect to get to the 1000f mark pretty quick....

Tonight I had a captiva on a car trailer coming from Bruce rock had to push rather hard on some hills but the highest temperature I got was 650 in the manifold. Stock tune just some extra boost.

Ben_W said:

We're talking about the egr port at the rear of the exhaust manifold. You have to completely remove the egr pipe and make a plate to go over the port which is solid enough to weld a nut or tap a thread to accept the thermocouple probe. And then also block the egr port on the inlet side.

Click to expand...

Thanks Ben, still a bit confused here. I thought I've managed to get it but then I don't.

So in the photo here from the EGR block thread:

http://www.navara.asia/attachment.php?attachmentid=1805&d=1283496916

I've blocked #1 in the photo already, which is the egr port on the inlet side, correct?

So I take the pipe off completely, add another plate on the bottom end of the pipe and stick the probe on there?

I did check the photo in your garage but it looked somewhat different to the one in the egr block thread.

Also as a side note does anyone have a photo of where the probe fits when it's pre-turbo?

slepax said:

Thanks Ben, still a bit confused here. I thought I've managed to get it but then I don't.

So in the photo here from the EGR block thread:

http://www.navara.asia/attachment.php?attachmentid=1805&d=1283496916

I've blocked #1 in the photo already, which is the egr port on the inlet side, correct?

So I take the pipe off completely, add another plate on the bottom end of the pipe and stick the probe on there?

I did check the photo in your garage but it looked somewhat different to the one in the egr block thread.

Also as a side note does anyone have a photo of where the probe fits when it's pre-turbo?

Click to expand...

That lower pipe in the photo in that link, #2, you need to follow that to the other side of the motor to where the exhaust manifold and turbo are. Then remove the pipe and put a decently thick plate on the exhaust manifold side, with the probe fitted to it. you will then have to blank the lower port in that picture in the link above as the pipe around the back of the engine will no longer be there.

Hopefully that makes sense..?

Also, as said by others. You need to make sure the probe is actually in the exhaust flow to work optimally. Best way is to install as described above; run the car for a few minutes, then let it cool and pull the probe out again and examine the tip. If it is in the exhaust flow, it should show black soot on the tip. If not, you make need to work out how to get it in further (possibly with a longer tipped probe or how you've drilled and tapped the plate etc)

Thanks guys, just to be completely and utterly sure I understand this please tell me if I got this right.

The exhaust manifold has two outputs, one goes to the EGR, the other one goes to the turbo. So my options are:

EGR probe:
Block the EGR output with a blanking plate, mount the probe on the plate, and also block the other side of the EGR tube (on the EGR volume control).

Pre-turbo probe:
Tap on the pipe leading to the turbo, I assume the closest to the exhaust manifold the better.

Also shown in the attachment.