Technical EGR Heaven and Hell

[pondweed]

https://www.fiatforum.com/stilo/163320-egr-valve-remove-clean-modify.html

on Stilo forum - they are rather more advanced than us. Lots of talk of redesigned gaskets too...! Worth reading as lots of pics which are roughly the same as ours.

also lots of references to cleaning the MAP sensor aperture which gets very blocked up - right next to the EGR.

 

[pondweed]

just fashioned a gasket and blocked the EGR flexi entrance to the inlet manifold. Seems to pull better in 5th and no engine light has come on. ('05 115JTD)

 

[Peat]

Well done that man!

Had it not been for the fact that the Singapore GP has been on the box and I'm also an idle Barsteward and prefer to not work unless it's absolutely necessary, I too may have blocked off the EGR.

I still have to mackle(?) a decent piece of metal sheet, don't want it to destruct and find it's way into the engine because it isn't up to the job.

If I had been having issues it would have been done but the car is running tickety boo at the moment. Oh well, there's always tomorrow. Oh no the GP is on!

When I do get around to it I will be blocking the exhaust end.

Once again - Well done.

Peat

 

[pondweed]

hmmmm.... will 'square biscuit tin' top material be ok?? the exhaust has been cooled by then so I'm hoping wont be too hot on 'tother side...

 

[Peat]

It may well be the case as your biscuit tin is located at the 'cool' end but if it's not too great an effort you would be well advised to replace it will a 2/3mm steel gasket.

Remember the 'cool' end is nearest the intake!

That's why I haven't done mine yet, and the fact that I'm an idle git ;¬)

Peat

 

[Peat]

Just to report that I at last got around to blanking the EGR and although I started to do the Exhaust end I resorted to the inlet manifold pipe end as being the easier way to go. You were absolutely right Pondweed top end is the better.

After having completed the blanking with a 2mm sheet I took it for a run of approximately 25 miles and my first impressions are that it's smoother through the rev range, appears to be better on consumption and I swear it's running quieter.

So no more worries about the damn EGR jamming open and embarrassing me with clouds of black smoke and no power should have done it years ago!

Peat

 

[SS069]

I'm seriously considering blanking off my EGR, I have removed it & cleaned + lubricated it, the thing has now got silky smooth plunger movement, but when I blow into either port, there is no air tight seal.......is this normal, if so will the exhaist gasses not make their way into the airfilter box indiction pipework....

I have made a 1mm blanking plate ready to blank the EGR off - where's the best place to blank it off though ???

I had a BMW E46 320d (2000/X reg) & I replaced the EGR with a by-pass (fully open) on that & the car was more resposive & nbetter on fuel too, would this be the case with the Fiat JTD 115 engine that i have in my Multipla

 

[pondweed]

I think the better response probably means that whilst its running more efficiently, that cancels outs any fuel saving. Its going to be physically combusting more on each stroke as there is less inert charge entering...?

 

[BikeDoc]

If it's not running as efficiently as possible though, you'll be using more throttle to compensate, burning more fuel.

 

[pondweed]

isn't this down to the definition of 'efficiently'?
Is introducing an inert charge of mucky gas efficient (as it lowers the effective cubic capacity when cruising) or inefficient as it reduces the potential combustion efficiency of the overall available capacity?!
I'm a bit confused by this...

 

[SS069]

regarding the EGR, I have stripped & it's moving freely now, but whe I blow into the inlet port (from the exhaust side, there is air passing through the outlet side....I'm usong my mouth & blowing through the EGR......is this right or should it be airtight

 

[BikeDoc]

isn't this down to the definition of 'efficiently'?
Is introducing an inert charge of mucky gas efficient (as it lowers the effective cubic capacity when cruising) or inefficient as it reduces the potential combustion efficiency of the overall available capacity?!
I'm a bit confused by this...

From Wiki...

EGR deletion in diesel engines is considered justifiable by a wide range of people, including the environmentally conscious. Although deleting the EGR system results in increased NOx levels, hydrocarbon emissions, Particulates, Carbon monoxide and Carbon dioxide are drastically reduced. Furthermore, EGR deletion results in an increase in fuel economy as high as 25%. Exhaust gas recirculated back into the cylinders adds wear-inducing contaminants and causes an increase engine oil acidity, which can result in an inefficient, poorly running engine. The increased level of soot also creates the need for diesel particulate filters to prevent environmental contamination.

Then further on it seems to contradict this...

In the past, a fair number of car owners disconnected their EGR systems in an attempt for better performance and some still do. The belief is either EGR reduces power output, causes a build-up in the intake manifold, or believe that the environmental impact of EGR outweighs the NOx emission reductions. Disconnecting an EGR system is usually as simple as unplugging an electrically operated valve or inserting a ball bearing into the vacuum line in a vacuum-operated EGR valve. In most modern engines, disabling the EGR system will cause the computer to display a check engine light. In almost all cases, a disabled EGR system will cause the car to fail an emissions test, and may cause the EGR passages in the cylinder head and intake manifold to become blocked with carbon deposits, necessitating extensive engine disassembly for cleaning

 

[pondweed]

thats a good writeup.
an 'increase in fuel economy of 25%' is positive, isnt it? Once again, always a bit ambiguous...

I dont think I'm getting any difference in fuel consumption.

 

[Peat]

Quote from Wiki
"In almost all cases, (1) a disabled EGR system will cause the car to fail an emissions test, and (2) may cause the EGR passages in the cylinder head and intake manifold to become blocked with carbon deposits, necessitating extensive engine disassembly for cleaning"


Taking (1) above, the statement is patently false for the UK as NOx is not measured and numerous people have passed the emissions test with the EGR disabled either by 'blanking' which is IMO the better method, or by disabling by other means which could possibly lead to (2) in some cases.

I have found that by blanking the EGR on my vehicle an '02 110 with 134K, consumption has improved and the engine feels more responsive.

Peat

 

[tinytim]

blanked the EGR on my 1.9jtd 110 Marea some time ago; also removed the butterfly valve; mpg improved from 51 mpg to 54 and better acceleration; never any black exhaust smoke now either; worth doing

 

[demag]

My Citroen Xm failed it's last test on smoke. It was a 2.5td and smoke was always an issue on them. A local diesel workshop blanked it off and he actually told me they are not needed on a diesel, because as Peat said NOx is not tested. Flew through the next day. My son had a Pug 306 diesel that started running awful. Thinking it was the egr I had a look. Well the gunge and crap in the induction system had to be seen to be believed! Blanking the egr made no difference. Took it to the same diesel bloke as above and it turned out the cat was blocked with this gunge. He ground out the cat housing and binned the cat. Rewelded the housing and it passed 2 more mots before he sold it. Apparently cats are not required for diesels either!

 

[st1vo]

Just thought I'd post my EGR 105 JTD experience. (and I'm only on the Wirral!)

I was getting poor fuel consumption 36mpg (no computer, just brim to brim) so plugged her up to the computer, it returned EGR valve.

I stripped it down and cleaned it out (but it was already pretty clean)

After re-assembling I noticed the vac pipe was disconnected at the bulkhead end!! What a ball ache.

Now it's running exactly the same and returning 35mpg.

Stumped!!

So should I make a plate and blank it off at the manifold end?

Surely disconnecting the vac pipe = blanking it off as it will be sprung shut?

 

[Peat]

Yes blank it off at the exhaust end and also get your MAF sensor replaced, if you have had it on for over 50K and ensure that it is a genuine Bosch, the repro units are just not up to the job. Also check the pipes to and from the turbo boost valve for leaks after cleaning it, as well as free movement on the turbo actuator arm on the bottom of the turbo.

Peat

 

[Brian Partridge]

Hi Peat,
Am about to remove EGR from the equation on my 2003 115JTD and just wondered whether your intervention had proved successfull in the long term.
I ask this as I note that the Marea forum seems top suggest that this is a diagnostic strategy rather than for long term running.
I could go down the cleaning route but prefer a long term solution.
Any feedback appreciated and I'll post on the forum in an attempt to trawl opinion widely though your solution appeals to me due to its simplicity.
Regards,
Brian