Quote:

I strongly do not recomend blanking of any of the EGR's as I have stated before the EGR has a cooling efect in the combustion chamber and can cause hot spots , increase cylinder head temp , the engineers have built these heads to work inconjunction with the EGR, and blanking them off efects this , I know yuo guys are saying it improves performance ,but if it efects reliability, leave off , I am seeing cracked heads again in the workshop and no less that two recently were running with blanked off EGR's, 2.5's by the way .

...anyone care to comment

DG wrote:

... is not without it's drawbacks particularly for those still in warranty...and thought it worthy of discussion

10forcash wrote:

EGR - no, butterfly - yes, removing that makes blanking the EGR's pointless, hot'ish gases being drawn in (rather than forced in) post turbo will only cause the cold air to expand creating a greater boost effect, personally I think we need some major recall to give D3'ers something to talk about instead of faffing around with tightly integrated emission systems

So how come removing the butterfly vv makes blanking pointless? The main reason for blanking, for most people, is because the EGR valve design is unreliable and driving the vehicle with 1 or 2 failed EGR valves is almost impossible. So the EGR is blanked to prevent a failed valve affecting engine performance, and the butterfly is removed to prevent the intake vaccuum that the engine would suffer with closed (blanked) EGR valves and closed butterfly valve. Any performance benefits (improved 'pick up' as reported by some) of the blanking procedure are a bonus, but not the main reason.
Regarding the recirculated gas increasing the boost effect - I can't see that being true as any boost increase will be cancelled out by the increased percentage of non combustible gas drawn / pushed into the engine.
If mine was still in warranty then I'd leave well alone, but now any recovery and repairs are paid for out of my own pocket I'm happier running with the blanks fitted, rather than pay LR £hundreds to fit new (flawed design) valves every couple of years. IMHO, and all down to personal choice of course

 Previously:
2005 D3 2.7 TDV6 S
1984 90 2.25 Petrol CSW
1992 90 200TDi Hard Top
1995 Discovery ES 300TDi
2003 90 TD5 Truck Cab

 

Quote:

EGR stands for exhaust gas recirculation. The purpose of this is to lower oxides of nitrogen emissions from the combustion chambers (& out the exhaust). When the combustion temperatures increase, so do the oxides of nitrogen produced. To this effect, exhaust gas is used to add into the combustion chamber to reduce temperatures, this seems a strange thing to do, exhaust gas being hot! The temperature of the exhaust gas is less than cylinder temperatures, when added back into the cylinders, less oxygen is available to be burnt, reducing temperatures & oxides of nitrogen. EGR can also be cooled via cooling system coolers to reduce temps further, as is the case on later TDV6's.
The increased temps by not having EGR will not increase temps by more than the engine can cope with, as there were many engines running without EGR before, & they coped

As MOT's smoke tests only measure visible smoke, blanking the EGR will not make the vehicle fail. In fact as EGR increases particulate emissions (soot) there is a likelyhood that visible emissions could well be less.

HTH
Steve

MacLeod 313 wrote:

...blanking the EGR's just takes away your ability to claim

Depends, I've had 1x EPB rebuild and 1x replacement steering wheel when out of both factory and LR ext waranties, both done by the same dealer who is aware the car is chipped (its obvious when driving a chipped D3!), and no queries about blanked EGRs.... perhaps you have too honest a face