Diesel Knock - Driving me insane! HELP!

[darkman884]

My CFCA runs noticeably better with the Tafmet kit fitted.

excellent
however there is only one downside to an egr delete , and its well documented , a slight ( barely noticeable) reduction in low down torque.
Everything else about an egr delete as we know is a win win .
especially the part where it just puts clean air in for combustion .lol
but this is about trying to isolate a knock,not the virtues of egr delete.

 

[FWhite]

excellent
however there is only one downside to an egr delete , and its well documented , a slight ( barely noticeable) reduction in low down torque.
Everything else about an egr delete as we know is a win win .
especially the part where it just puts clean air in for combustion .lol
but this is about trying to isolate a knock,not the virtues of egr delete.

Interesting. Not an expert, but would you try to explain the science behind your thesis of EGR helping to produce better torque at lows? More intake pressure (while warmer and with less oxygen)? Or is it another internet myth?

 

[DXX]

excellent
however there is only one downside to an egr delete , and its well documented , a slight ( barely noticeable) reduction in low down torque.
Everything else about an egr delete as we know is a win win .
especially the part where it just puts clean air in for combustion .lol
but this is about trying to isolate a knock,not the virtues of egr delete.

I was passing comment as you seemed to be implying that the EGR delete could be causing the issue.
I’ve never heard anybody mention before that the an EGR delete can reduce low down torque and I’ve been building, maintaining and operating diesel engines for 40 plus years. However I’m still learning, have you got a link to the such information, I can’t see how reducing combustion efficiency increases torque especially as the EGR closes when power is commanded.

 

[Sasquatch]

Its not as intuitive as one would think.

In terms of O2 available for combustion in the charge there is a reduction. However, its not a large percentage.

This loss of volumetric efficiency is largely offset by the raised intake temps, which reduce charge density (bad, but not tragic in a diesel) but actually improves combustion efficiency through better fuel vaporisation (good) and more even/complete burning (very good indeed.)

In NET terms a modern EGR makes effectively no difference to engine performance, and removal/deletion will not improve torque for these reasons. The Lord taketh away, but the Lord also very much giveth.

 

[darkman884]

I was passing comment as you seemed to be implying that the EGR delete could be causing the issue.
I’ve never heard anybody mention before that the an EGR delete can reduce low down torque and I’ve been building, maintaining and operating diesel engines for 40 plus years. However I’m still learning, have you got a link to the such information, I can’t see how reducing combustion efficiency increases torque especially as the EGR closes when power is commanded.

my BAD chaps ,,,
I have confused my thesis with the well known truth of the SWIRL FLAP DELETE LOL.
SO yes safe to ignore my post regarding egr delete

 

[darkman884]

however , when diagnosing an engine issue ,surely you need to start with a baseline and go from there.
i was in no way suggesting the egr delete was the cause , but to put it to standard to see if there was indeed a difference,ruling it out,thats all

 

[Bav]

Its not as intuitive as one would think.

In terms of O2 available for combustion in the charge there is a reduction. However, its not a large percentage.

This loss of volumetric efficiency is largely offset by the raised intake temps, which reduce charge density (bad, but not tragic in a diesel) but actually improves combustion efficiency through better fuel vaporisation (good) and more even/complete burning (very good indeed.)

In NET terms a modern EGR makes effectively no difference to engine performance, and removal/deletion will not improve torque for these reasons. The Lord taketh away, but the Lord also very much giveth.

Have you been assimilated by the AI collective?

 

[darkman884]

i too have been maintaining my 3 litre straight 6 bmw diesel engine for over 17 years .
also a bi-sequential turbo
it was many moons ago when i researched the "swirl flap" deletes that mentions a slight dip in torque.
i didnt do the swirl flap delete , i bought and fitted a brand new intake manifold instead.
i havnt done an egr delete either.
and its still buttery smooth on its original DPF at 212000 miles.

 

[Sasquatch]

Have you been assimilated by the AI collective?

Combustion is my thing.

 

[Bav]

Hopefully not spontaneous.

 

[Sasquatch]

Hopefully not spontaneous.

I have to be careful with my farts because of the risk of compression ignition!

 

[DXX]

I have to be careful with my farts because of the risk of compression ignition!

It’s not a hazard if you dress accordingly

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[Bertrum]

I have to be careful with my farts because of the risk of compression ignition!

Puts a whole new take on compression ring.

 

[lockettben]

ok , so reset the van engine, to baseline ,( im reading it that you have done an egr delete etc)
i mean remove the modulator and refit the egr system ,
this will, lf nothing else return about 10% of the low down revs torque you will have lost by mapping it out ,
see if it still has the same symptoms .
go from there

So I removed the EGR delete (Tafmet) This was my last straw before asking for help on here. It made no difference, if anything it's potentially a little worse.

 

[lockettben]

I managed to get a recording of it today. It's remarkable louder in person compared to the recording but hopefully you can hear it.

Link here


Thanks in advance

 

[darkman884]

so
, drive it and enjoy it
,or sell it ,,,,,
thinking I've just dodged another catostrophic wallet emptying financial suicide grenade.
the more i read up on these engines , the more i cringe.
please believe me , im not trolling ,
but engines make noises, diesels make more noise,some diesels make more noise than other diesels

 

[DXX]

Are you sure you don’t have an exhaust leak at the manifold? I hear what sounds like noisy hydraulic valve followers and a possible exhaust leak. Oddly I can’t hear the turbochargers at all?

 

[darkman884]

I've just listened to the link,,,
my god , that sounds worse than a 1995 xud 1.9 psa diesel.
something is seriously wrong there my friend.
its errrr, very agricultural.
i appreciate my comments are not very helpful , but it just sounds bad

 

[DXX]

It sounds a bit gutless, like I said I can’t hear the turbochargers and it seems slow to react.
Doesn’t sound like my CFCA.

 

[darkman884]

Are you sure you don’t have an exhaust leak at the manifold? I hear what sounds like noisy hydraulic valve followers and a possible exhaust leak. Oddly I can’t hear the turbochargers at all?

maybe put a ink up of how yours sounds for a direct comparison?