Thread: D4 3.0 EGT sensor locations

There is only one in non dpf vehicles if I'm not mistaken. It is just downstream prior to the oxygen sensor.

Jc

Originally Posted by justinc

There is only one in non dpf vehicles if I'm not mistaken. It is just downstream prior to the oxygen sensor.

Jc

Thanks jc that helps. My iidtool says there are 5 but I'm only getting readings from two. The other 3 must be related to DPF. Mine has the twin turbo so I'm guessing I have a sensor on each side. I guess the 2.7 has only one. ???

Are the sensors before or after the turbos?

I read between 350 to 500 c on bank 1 depending on engine load. Which I'm assuming is the primary turbo side. ?

On the other, i mostly read 120 c. But when the revs go above 2200 it starts increasing up to 400's. I'm assuming this aligns with the second turbo kicking in. ?

The 3litre has 2 yes. One is definitely after the primary snd i guess as you have observed the other after the secondary turbo. There are no upstream ones.
Should read the thread title first shouldn't i...🙄

Jc

Here are some example iidtoolBT screenshots from my iPhone as I drove from Newcastle toward Sydney on the motorway.



1. 6th gear , 105kph, 1800kg camper trailer, up a small hill. Primary turbo working quite hard (see egt heat on bank 2), secondary not engaged (120c) ,~1900rpm.



2. Change down to fifth, revs kick up at about 2400, secondary turbo kicks in (see egt on bank 1 heat up, and manifold pressure increase)



3. Coming down the other side of the hill, the work load has dropped off (manifold pressure is low, secondary turbo is off and cool, primary is still hot), egr's open up to recirculate unburnt particles.

I think that is what is going on.



(PS, I show bank 1 on the right of screen, because from the drivers seat, its on the right in front of you.)

FWIW, I now change down from 6th to 5th when I see the calculated load get into the 90's. Fuel economy doesn't get any worse, and it feels better to be using both turbos instead of asking the primary to work really hard below 2000 rpm. Don't know if I'm doing the right thing but it feels good.

Those figures are not too excessive for modern turbocharged engines, even for downstream, the ecu will do its job by lessening temps at the right time. But yes if high ambient temps and working hard is on the cards then 5th would certainly help☺.

Bank 2 EGT remains on 455.0 degrees exactly in all 3 scenarios? That's not my understanding of egt's. Am I missing something? Cheers Matti.

I'd hate to pay for an oil change - oil level at 43 metres! :-/

Originally Posted by matti4556

Bank 2 EGT remains on 455.0 degrees exactly in all 3 scenarios? That's not my understanding of egt's. Am I missing something? Cheers Matti.

Just a coincidence when doing the screen grab. Bank 2 goes up and down a lot (~150 to 550)