EGR experiment.
#21
05-16-2015, 06:14 AM
Please report further Imtattoo as you get used to it; now I'm used to mine without vacuum valve connected, I have noticed the following...
1) On starting, the immediate firing sounds very slightly different.
2) On light pedal operation, the slightest movement of the pedal downward is livelier. Not a lot, but it's noticeable.
3) The "coast" feature of the autobox below abt. 40mph and foot-off pedal, seems to be extended. If it proves the 'box has the vacuum connected to it, I can see the vacuum has changed in character, i.e. more of it. Otherwise, it's my imagination.
Leedsman.
1) On starting, the immediate firing sounds very slightly different.
2) On light pedal operation, the slightest movement of the pedal downward is livelier. Not a lot, but it's noticeable.
3) The "coast" feature of the autobox below abt. 40mph and foot-off pedal, seems to be extended. If it proves the 'box has the vacuum connected to it, I can see the vacuum has changed in character, i.e. more of it. Otherwise, it's my imagination.
Leedsman.
#22
05-16-2015, 06:31 AM
Please report further Imtattoo as you get used to it; now I'm used to mine without vacuum valve connected, I have noticed the following...
1) On starting, the immediate firing sounds very slightly different.
2) On light pedal operation, the slightest movement of the pedal downward is livelier. Not a lot, but it's noticeable.
3) The "coast" feature of the autobox below abt. 40mph and foot-off pedal, seems to be extended. If it proves the 'box has the vacuum connected to it, I can see the vacuum has changed in character, i.e. more of it. Otherwise, it's my imagination.
Leedsman.
1) On starting, the immediate firing sounds very slightly different.
2) On light pedal operation, the slightest movement of the pedal downward is livelier. Not a lot, but it's noticeable.
3) The "coast" feature of the autobox below abt. 40mph and foot-off pedal, seems to be extended. If it proves the 'box has the vacuum connected to it, I can see the vacuum has changed in character, i.e. more of it. Otherwise, it's my imagination.
Leedsman.
I will go later and do littlebit more test driving and will try to remember all differences. But at the moment feels like i get out of this engine what i should get.
#23
05-24-2015, 06:34 AM
I can now give a preliminary report on mpg. with the vacuum activation of EGR 2.8CRD diesel disabled:--
There is no dramatic change in fuel consumption, but the small improvement was more obvious in city traffic, by about 1 to 1.5mpg at 28mpg/city. The computed readout was very accurate this time and agreed with the brim-brim. City traffic on test was especially bad with lots of roadworks and delays. On the other hand, ambient temperatures were not cold.
Highway/motorway driving did not show any discernible improvement.
All in all I thought the manufacturers had done a reasonable job with EGR regarding fuel consumption, but I have concerns that EGR may clog up the injectors more rapidly than without EGR. Clogged injectors inevitably degrade fuel consumption, and the hotter they run the better as regards clogging. Carbon cannot be dissolved away as any proper chemist will confirm, sheer heat being the best to burn it away. The whole point of EGR is to cool the combustion, thereby not burning the carbon away as effectively. Therefore I shall keep an eye on fuel consumption as there could be a gradual improvement over a much longer time period. I will of course report if this be the case.
I have a feeling that the city mpg improvement was down to better cold running mpg as was so indicated by the computed readout. Right from startup the instantaneous reading was better. This is logical if the combustion temperature is hotter without the EGR. This effect might even explain poor fuel consumption generally with diesels in cold weather.
Leedsman.
n.b. Physically removing the EGR equipment is a different operation, and I understand there is a "restrictor" in the air input to this engine, which commercial firms remove and substitute with a non-restricting pipe. Of course, whether going to the trouble of physically removing EGR equipment is cost-effective or not is a moot point.
As we all know, good mpg is a matter of attending to the little things that affect it, and I see EGR as one of those little things, along with tyre pressures, no brake-bind etc. See to all these little things and the cumulative effect and saving is worthwhile. I won't say anything about style of driving as that's a big thing...
Addendum 28/05/15.
It's now becoming more obvious that less fuel is being consumed during the warm-up process. The engine is not warming up any faster according to my own temp. gauge on the cyl head, but it's using less fuel doing so. It is using less fuel just getting about in city traffic too. So it appears that no EGR is better for the most difficult fuel consumption areas, warm-up and city traffic. I shall keep an eye on it over the next few months to see if the injectors become more efficient with less soot deposit now.
As every complaint I've heard on tv about diesel pollution is about the soot production and its effect on asthmatics, it would seem to me logical that stopping EGR by whatever method, and thereby reducing soot and other unburned hydrocarbons production, will be beneficial to the health of city/town dwellers. Also it's logical that better fuel consumption in towns and cities will result in less CO2 production. But then, since when did logic come into these kind of matters?
Yes, I know all about NOX production, it's not a problem here in UK.
There is no dramatic change in fuel consumption, but the small improvement was more obvious in city traffic, by about 1 to 1.5mpg at 28mpg/city. The computed readout was very accurate this time and agreed with the brim-brim. City traffic on test was especially bad with lots of roadworks and delays. On the other hand, ambient temperatures were not cold.
Highway/motorway driving did not show any discernible improvement.
All in all I thought the manufacturers had done a reasonable job with EGR regarding fuel consumption, but I have concerns that EGR may clog up the injectors more rapidly than without EGR. Clogged injectors inevitably degrade fuel consumption, and the hotter they run the better as regards clogging. Carbon cannot be dissolved away as any proper chemist will confirm, sheer heat being the best to burn it away. The whole point of EGR is to cool the combustion, thereby not burning the carbon away as effectively. Therefore I shall keep an eye on fuel consumption as there could be a gradual improvement over a much longer time period. I will of course report if this be the case.
I have a feeling that the city mpg improvement was down to better cold running mpg as was so indicated by the computed readout. Right from startup the instantaneous reading was better. This is logical if the combustion temperature is hotter without the EGR. This effect might even explain poor fuel consumption generally with diesels in cold weather.
Leedsman.
n.b. Physically removing the EGR equipment is a different operation, and I understand there is a "restrictor" in the air input to this engine, which commercial firms remove and substitute with a non-restricting pipe. Of course, whether going to the trouble of physically removing EGR equipment is cost-effective or not is a moot point.
As we all know, good mpg is a matter of attending to the little things that affect it, and I see EGR as one of those little things, along with tyre pressures, no brake-bind etc. See to all these little things and the cumulative effect and saving is worthwhile. I won't say anything about style of driving as that's a big thing...
Addendum 28/05/15.
It's now becoming more obvious that less fuel is being consumed during the warm-up process. The engine is not warming up any faster according to my own temp. gauge on the cyl head, but it's using less fuel doing so. It is using less fuel just getting about in city traffic too. So it appears that no EGR is better for the most difficult fuel consumption areas, warm-up and city traffic. I shall keep an eye on it over the next few months to see if the injectors become more efficient with less soot deposit now.
As every complaint I've heard on tv about diesel pollution is about the soot production and its effect on asthmatics, it would seem to me logical that stopping EGR by whatever method, and thereby reducing soot and other unburned hydrocarbons production, will be beneficial to the health of city/town dwellers. Also it's logical that better fuel consumption in towns and cities will result in less CO2 production. But then, since when did logic come into these kind of matters?
Yes, I know all about NOX production, it's not a problem here in UK.
Last edited by Leedsman; 05-28-2015 at 09:51 AM. Reason: Bad spelling.
#24
05-24-2015, 01:54 PM
Just a little interest here as I'm doing some servicing work and repairing rattles. The EGR valve is at back of engine and not so easy to get at. Looking up from below am I right in assuming that the delivery pipe from EGR runs around engine and is bolted to underside of inlet manifold at front. So is blanking it here not the easy option.
#26
10-05-2015, 08:48 AM
Small update with my disconnected egr. Its been while now and done alot of driving. Now my EGR is back in action. Done one long trip aswell. It was 400mile .. After all that time i realized that drive is smoother ..noise is little bit lower and and fuel economy is good. This 400 miles costed my under £ 60. My sat nav said it will cost me £54 and it was close . Im happy with results. It stays connected at the moment. Little bit more smoke is back but thats fine .
#27
11-21-2015, 11:27 AM
A little update from me, 2003 2.5 CRD I pushed a Ball bearing into a piece of spill pipe cut the Vac hose that goes to the EGR control valve on the front of the engine from the Servo and put in this spill pipe to join the plastic pipe, I have been doing tank to tank driving to record the mileage, I cant give town and motorway mileage as we live in a regeion of France where mixed driving of town fast roads and huge mountains are an every day event, what I can say is over all the mileage has improved by about 3.4MPG the engine has more torque, and extremely more drivable, I suppose I was lucky and the EGR Valve was able to stay shut and was not jammed open.
#29
11-22-2015, 02:13 PM
Seconded ...................... much missed ...................Last Activity on this site: 07-24-2015 09:51 AM
Congratulations John Norrish, that's a good return, most people I read of seem to get 2-3 regardless of the particular marque since the then [1992] to the 'Euro 6'. Each year manufacturers get more and each year our legislators steal any improvement we the people who pay may have benefited from.
Congratulations John Norrish, that's a good return, most people I read of seem to get 2-3 regardless of the particular marque since the then [1992] to the 'Euro 6'. Each year manufacturers get more and each year our legislators steal any improvement we the people who pay may have benefited from.
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