Thread: EGR Blank on 08 TDV6

Originally Posted by Ean Austral

I also see the bloke on the UK site is having issues as well


Will see how we go.

Cheers Ean

Isn't that some other guy who has got a hole drilled in his blanks. I thought the guy who first did it is still OK.

Originally Posted by garrycol

Isn't that some other guy who has got a hole drilled in his blanks. I thought the guy who first did it is still OK.

You could be right Garry, didn't really read it that thouroughly to be honest.

Will log on and read with abit more attention this time.

I still cant understand the fault that logged, excessive EGR presure, I assumed by blanking the EGR you just got good clean air on the inlet side, but need to understand how the system works a bit better me thinks.

I would have thought a MAF fault would have been more likely.

Anyway, will see how long it goes for this time, worse case is will put the EGR pipes back on.

Cheers Ean

Now you understand why I preferred someone else to be the guinea pig

I hope it all works though.



Garry

I suspect the MAP sensor is registering considerably more pressure than there would be if the butterfly was still in place. However with the butterfly in place, there might be too litle pressure...

EGR occurs whilst cruising on light throttle. At 100 kph EGR is probably not occurring at all because the engine is working too hard, nor on overrun when no fuel is being used. Backing off slightly at 100 kph is more likely to trigger EGR.

Well tried to get the fault to register today with no joy.

Took the car for a burn trying to set it off in both D and sport mode, fanged from standing starts then backed off... sat on 110 the backed off and let it coast down to 40.. tried stabbing the accel and back off, all with no fault appearing, so will keep driving as per usual and see if it decides to appear again.

More confused than anything now.

Cheers Ean

Originally Posted by Ean Austral

I did the blanking as per the BAS write up, and drove the car with no probs, went for a burn up the freeway at 100ks backing off the pedal and re-accelerating plenty of times, thinking the fault would register when I backed off.Car done approx 180kms over 8 days no faults.

Our daughter drove the car to the airport at 5am the other morning, and with no traffic and just cruising along the fault registered, so unsure what triggered it. The only thing I can think of is it must be the MAF registering extra air flow or something, as I can see how the ECU can get a reading from the EGR if its blanked..But as you say I dont fully understand how the EGR works...I follow the priciple, but thats about it.

Cheers Ean

I haven't been into the code in the TDv6 ECU (I don't really want to), but even the most simple diesel ECU's controlling EGR have several maps and sensors to work from.

My work car had three maps controlling EGR. The first was map to switch it on/off varying amounts triggered on fuel injection quantities (engine load) and rpm.
The second map was EGR valve target position. The third map was flow correction, essentially how much it expected the MAF readings to drop.

In this vehicle I had blanked the EGR shortly after I got it (no fault codes), but it wasn't until I could get into the ECU and flatten out these three maps that performance improved. The restricted MAF values were limiting fuelling in those rpm/load instances where it was trying to still activate the EGR valve.

So where am I going with this?
Blanking EGR is kind of futile on a modern engine. The best way to acheive no EGR is by recoding the ECU, then you can blank it off if you wish (it will be closed anyway). In europe this appears to be commonplace in remapped cars. In Aus and NZ, it appears to be unheard of.

Originally Posted by Dougal

I haven't been into the code in the TDv6 ECU (I don't really want to), but even the most simple diesel ECU's controlling EGR have several maps and sensors to work from.

My work car had three maps controlling EGR. The first was map to switch it on/off varying amounts triggered on fuel injection quantities (engine load) and rpm.
The second map was EGR valve target position. The third map was flow correction, essentially how much it expected the MAF readings to drop.

In this vehicle I had blanked the EGR shortly after I got it (no fault codes), but it wasn't until I could get into the ECU and flatten out these three maps that performance improved. The restricted MAF values were limiting fuelling in those rpm/load instances where it was trying to still activate the EGR valve.

So where am I going with this?
Blanking EGR is kind of futile on a modern engine. The best way to acheive no EGR is by recoding the ECU, then you can blank it off if you wish (it will be closed anyway). In europe this appears to be commonplace in remapped cars. In Aus and NZ, it appears to be unheard of.

Not to sure of why it would be futile, when the amount of krud build-up on the inlet side of the engine on a car with only 80,000ks is quite amazing and surely cannot be good for the engine.. I also believe it cant be doing the oil alot of good..but that is my own personal opinion, I dont have any facts or figures to prove so.

It is for these reasons that I wanted to blank the egr's, plus the fact that they seem to be a costly item when they do fail, I am not trying to get any major performance change, altho I wont complain if it does come as a bonus of the blanking.

Cheers Ean

Blanking EGRs will not result in engine performance improvements (unless there is something wrong in the first place) noting they are closed (same as when blanked) in the performance cycles of the engine. EGRs are blanked to save $$$ - in the order of $1500 to $2000 to get both EGRs replaced at a stealer.

I guess there is merit in looking at the blanking and error light issue from the ECU perspective but as far as the later TDV6, TDV8 and SDV6 engines no one in Europe has come up with a solution as yet and there are no 100% solutions. A couple of people in the UK have blanked the eu4 and leter engines without issue but most have not been successful.

Garry