Viper Panda said:

im wondering if the inlet pipe is blocked causing the engine warning light and flagging and egr fault?

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Of course, it does !

Check the voltage on emitter of transistor (behind diode). On idle it shoult be the same as at the cutted wire at MAF. Then check on 1000/min, 2000/min, must be still the same. Some resistors has different resistance than should have. It couses wrong voltage on emitter and ECU read error.
I had error "too high voltage from MAF", I check and there was 4,5V instead 2,25V I connected potentiometer and now can regulate resistance.

PS: sorry for my English. :worship:

bogo78 said:

Of course, it does !

Check the voltage on emitter of transistor (behind diode). On idle it shoult be the same as at the cutted wire at MAF. Then check on 1000/min, 2000/min, must be still the same. Some resistors has different resistance than should have. It couses wrong voltage on emitter and ECU read error.
I had error "too high voltage from MAF", I check and there was 4,5V instead 2,25V I connected potentiometer and now can regulate resistance.

PS: sorry for my English. :worship:

Click to expand...

Ok so wire on maf connector should rear 4.5v? and on the circuit at the transistor after Diode it should rear 2.25v?

near 2.25v on MAF, and at the transistor the same.
4.5v was in my case too high.

g8rpi said:

Hi,
The purpose of swirl / restrictor plates is not to reduce the amount of exhaust gas recirculated, it's to improve the mixing of the exhaust gas and inlet charge.

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Where did you get this information from...??

So many EGR problems occurs on older jtd engines, Fiat and Bosch engineers had no other option than to reduce the amount of exhaust gas passing the EGR by fitting a restrictor plate...
It wil not mix anything, but even if it should, it wouldn't make any difference in fouling the engine at all...!!

Btw, VW, Audi, Seat and Skoda can tell you what's legal or illegal on Diesel engines for sure...

Peter Pick-Up said:

Where did you get this information from...??

So many EGR problems occurs on older jtd engines, Fiat and Bosch engineers had no other option than to reduce the amount of exhaust gas passing the EGR by fitting a restrictor plate...
It wil not mix anything, but even if it should, it wouldn't make any difference in fouling the engine at all...!!

Btw, VW, Audi, Seat and Skoda can tell you what's legal or illegal on Diesel engines for sure...

Click to expand...

There are plenty who won't agree with me, but I HATE the EGR system. It is nothing but trouble, and there are more efficient ways of doing the same job.

The EGR system is designed primarily to reduce NOx (Nitrogen Oxides and Dioxides together). NOx is produced in a diesel engine at very high temperatures - such as at peak milliseconds within the combustion chamber.

The EGR valve recycles exhaust gas, which is basically an inert gas mix, along with pollutants such as partially burnt fuel and its related solids - and this dirty mix, pouring into the combustion chamber, lowers its temperature. It’s the lower temperature that reduces NOx formation.

Unfortunately, in lowering the combustion temperature more particulates are produced, because the lower temperature makes for incomplete combustion. This reduces engine efficiency, increases wear, dilutes and acidifies the lubricating oil with carbon particulates that wash past the rings, and also shoves particulates down the exhaust pipe.

So a DPF is installed in the pipework, which in theory catches the pollutants. Crazy thing is, a DPF wasn’t needed before the advent of the EGR. In practice, the DPF blocks up, so it has to go into a ‘regen’ cleaning cycle which uses neat fuel and very high temperatures and pours out a concentrated dose of pollutants that you can see and smell! And every so often you have to buy a new DPF. Some tuners now suggest that if the EGR is deleted, there is no need to remove the DPF because it will not block prematurely.

What about the CAT? It is fitted to convert carbon monoxide and hydrocarbons (your dreaded partially burned fuel) into less harmful carbon dioxide and water. It is not an ideal solution because CO2 still adds to the problem of global warming.

Unfortunately, due partly to the actions of the EGR valve, the CAT also gets blocked up. As it gets blocked you lose power, and then you compensate by using a heavier right foot. This burns more fuel and the whole cycle gets worse and costs you money. (An easy way to check for a blocked CAT is to measure the temperature of the pipework immediately before and after the CAT with a probe. A big difference indicates a failing CAT).

So from an environmental viewpoint the EGR system has poor long-term value because it is without doubt responsible for premature wear in a number of components, which all have to be manufactured and replaced. That is why many owners go for an EGR delete. You then get cleaner burn, slightly more power, much longer engine, CAT and DPF life, together with cleaner oil and less fuel use.

Rant over.

Reply to Peters comment,

The EGR valve is proportional, not just open / closed and the control is closed loop (on the mJTD 16V at least using PWM electrical drive) so putting a restrictor plate in causes the valve to open further to pass the required amount of gas. As the valve is spring loaded closed, opening it further increases the forces involved making it less likely to stick.
If the plate was just a restrictor there would be just one hole, not 4 (or 3 for the 8v). 4 small holes with the same flow is higher velocity than one and as it's a thin plate there is turbulent flow which promotes mixing of the exhaust gas and inlet charge. Mixing the gases promotes even burning, letting the exhaust gas do it's job and improving engine efficency as if it's not mixed properly the burn will be uneven.
And as VW have found out, mssing with the emission control system IS illegal.

Robert G8RPI.

Sweetsixteen said:

...... It is nothing but trouble, and there are more efficient ways of doing the same job.
.......
a DPF wasn’t needed before the advent of the EGR. In practice, the DPF blocks up, so it has to go into a ‘regen’ cleaning cycle which uses neat fuel and very high temperatures and pours out a concentrated dose of pollutants that you can see and smell! And every so often you have to buy a new DPF. Some tuners now suggest that if the EGR is deleted, there is no need to remove the DPF because it will not block prematurely.
.........

So from an environmental viewpoint the EGR system has poor long-term value because it is without doubt responsible for premature wear in a number of components, which all have to be manufactured and replaced. That is why many owners go for an EGR delete. You then get cleaner burn, slightly more power, much longer engine, CAT and DPF life, together with cleaner oil and less fuel use.

Rant over.

Click to expand...

Hi,
The more efficent way is a selecive CAT. This need additional nitrogen which is typically suppled by injecting urea (AdBlue) more cost and more to go wrong.

Why do you say DPFs were needed because of EGRs? DPFs trap particulates which are produced with or without EGRs. DPFs are just anoter steo in reducing emissions. You don't "have" to buy a new DPF, they are not a service item and do not need replacing if the car is used and serviced as intended. The main cause of DPF failure is blocking by ash that comes from the engine oil, not the EGR.

Were is your evidence for all these EGR deletion benefits, particuarly "much longer engine life"? EGR has been around a long time, The first car I had with it was built in the early seventies (2l 16V sports car). Yes there are issues with some implementations, but tthe majority of cars, petrol as well as diesel, now have it and run just fine.
We have to reduce th polution we are causing, so until we are using electric and or hydrogen internal combustion powered cars with the electricity and hydrogen produced by fast neutron nuclear powerplants, we will just have to put up with the emission control equipment on our fossil fuel burners. Oh, a mJTD with EGR and DPF is still more powerful and economic than a typical 1.9l engine of 10 or twenty years ago.

Robert G8RPI.

I ran an official 4 hole restrictor plate in my Alfa GT jtd for about 6 months, didn't notice any difference at all.
After removing this 4 hole gasket ( to fit a closed blanking plate) I was amazed about the huge amount of sooth that was build up around those holes, just shocking..!

Looking at the post from Robert (G8RPI):

'You don't "have" to buy a new DPF, they are not a service item and do not need replacing if the car is used and serviced as intended.'

What does ‘used as intended’ mean? My brother runs a VW Golf diesel. His motoring is all short journeys. VW Service Manager tells him to go for a long hard blast every week, because otherwise the EGR will gum up and the DPF will block. His reply, ‘I drive my car responsibly. Why should I have to make extra journeys, using fuel, adding mileage, increasing wear, and polluting the planet, just to free up my EGR and clean out my DPF?’ Is that ‘used as intended’?

I also run a Mercedes diesel. At 123k miles the DPF had to be replaced due to blockage, and the EGR had to be stripped and cleaned out. That was an unnecessary bill of £1000 for a ‘non-service’ item. Since then I have deleted the EGR. The car now runs better than ever at 156k miles, and Mot tests show the exhaust is very clean.

'Mixing the (EGR) gases promotes even burning, letting the exhaust gas do it's job and improving engine efficency.'

Not true. The EGR system works against maximum efficiency. It reduces NOx by deliberately lowering the optimum combustion temperature. It introduces inert and dirty recycled exhaust products, which interfere with the normal compression-ignition process. The engine runs at reduced efficiency and produces more particulates as a result.

'The main cause of DPF failure is blocking by ash that comes from the engine oil, not the EGR.'

Also not true. Plenty of low ash oils about. Low SAPS oils are prefixed with a C, and when you use the manufacturer recommended oils that’s what you get.



Look at the photo here. It is of a Merc inlet manifold. That muck is caused by the EGR system - not ash from sump oil. On the Merc, BMW and other cars, swirl flaps are fitted to the inlet manifold. These jam because of EGR dirt, and the engine then runs rough. When they jam, the actuator motor seizes and burns out. This throws a limp fault, and if you’re far from home it means a breakdown service, another filthy and unnecessary strip down, clean-out job and new parts. More pointless expense. That’s why I said that the EGR system makes poor environmental sense. It’s crude and inefficient.

True, the EGR system reduces Nox, but in doing so the trade-off is a lot of extra grief, extra cost and more pollution elsewhere.
Both the motorist and the planet pay heavily for it.

Hi,
If it's not ash that blocked the DPF on your Merc, what was it? Don't say muck from the EGR because the exhaust gases go through the DPF with or without EGR. Yes they are supposed to use low ash oil, but note "low" ash, not no ash. Was your Merc serviced by a main dealer? Are you sure it was always filled and topped up with the correct oil? I've experienced at least 3 main dealers putting the wrong oil in my car, in one case with immediate effect on the car.

My comment on mixing the gases refers to the improved mixing promoted by the "restrictor" plate over the poor mixing without it. I've never suggested that EGR improves performance in any way,

You say "True, the EGR system reduces Nox, but in doing so the trade-off is a lot of extra grief, extra cost and more pollution elsewhere." Explain the "more poution elsewhere"? Apart from a slight increase in CO2 due to the small reduction in efficency, NOx is is worse at a local level than CO2. MOTs won't indicate that an exhaust is cleaner with regards to NOx, Diesels are only tested for smoke and petrol engines for CO and hydrocarbons.
Have you told your insurance company that you have deleted the EGR on your car?

Robert G8RPI.

Robert is absolutely correct in what he is saying.

Proper functioning of the EGR system is necessary in order to control NOx emissions, and even then, cars using this technology generally produce far more NOx in real world driving than would be permitted in static tests. If we are to continue using diesel engines in passenger cars and meet EU targets for urban air pollution, I suspect it will prove necessary to introduce SCR systems similar to those currently used on trucks and buses.

There are some relevant technical references in this post.

IMO deleting an EGR is an environmental crime on a level with flytipping asbestos.

The sooner that testing for the presence of a correctly functioning EGR system (where originally fitted) becomes part of the MOT, the better.

jrkitching said:

IMO deleting an EGR is an environmental crime on a level with flytipping asbestos.

Click to expand...

The same could be said (and our government soon will) for owning a diesel, full stop.

There seems to be some data everyone's missing.

We all know what EGR operation does, but how efficient is it at doing what it's meant to? Yes one will reduce nitrogen oxides, but by how much?

Seems work has been done to measure the reductions and it isn't as big as everyone thought without fudging the results (looking at no one in particular) and there are trade off in increases in some other harmful emissions. (carbon monoxide for one)

EGR flow isn't a constant, it increases and decreases with engine load, the closer to 100% load, the closer to 0% EGR flow, that's why they open and close.
So the NOx produced under these 100% conditions would be the same.
No EGR flow and no EGR results in the same NOx emissions.

EGR operation works better (but not completely) at partial loads.
Research (available from West Virginia University, yes those pesky thorns in VW's side) concludes the reductions with EGR between 40 and 80% load are still very harmful to life. (no surprises there then)
Under this load EGR operation again isn't active, so results are similar with and without.

So the area we're all interested in is the reductions in NOx with engine loads between 40 and 80% and their research shows there is between 0.6 and 2.5 g/kw-hr reduction of NOx between these loads.

Typically at 60% load with EGR operation they found their test engines produced 2 g/kw-hr compared to 2.8 without.

It seems because of this work, they became suspicious of the results reported from certain VW engines.

So basically, there's dirty and slightly dirtier!

The point is that EGR does reduce harmful emissions. How well it does it under different conditions and / or compared to more recent (and expensive) alternatives like selective CATs, is irrelevant. If EGR is fitted to our car we have to live with it.
The term "dirty" is subjective. In terms of particulates, my '06 1.9 Diesel Croma with DPF puts out less than a new "Ecoboost" 1.8l petrol Ford Focus. Particulates are an issue with the latest direct injection petrol engines.

Robert G8RPI.

It's not irrelevant and you don't have to live with it, you can always scrap your car and buy a bicycle or walk, but billions all around the world aren't going to.

The emissions problem has more or less always been the same vehicle to vehicle, sure there have been some successful attempts to clean the engine up, but what's changed is the amount of vehicles producing them.

A "little" whatever out of one exhaust now needs to be multiplied by billions, where not long ago it was admitted more out of the pipe, but only multiplied by millions.

Just a thought, anyone on here has already swapped an internal combustion engine for an electric?

Goudrons said:

Just a thought, anyone on here has already swapped an internal combustion engine for an electric?

Click to expand...

:yuck:

Better wade in again here, as I seem to have started this.

My point about the relative ineffectiveness of the EGR system was that, in reducing Nitrogen Oxides and Dioxides - like Medusah's heads - it produces problems elsewhere which unfortunately add to global pollution and wasteful use of ever-scarcer resources. I stand by that. It is a crude arrangement, quite probably cobbled together by manufacturers to beat EU Regs.

As Goudrons suggests, until we learn to properly manage our planet - maybe by lowering our expectations, walking (remember walking?), cycling, or harnessing 'free' power for our transport needs - pollution of one kind or another will stay with us.

While greed and profit are in the driving seats, we will not achieve these goals.

Goudrons said:

It's not irrelevant and you don't have to live with it, you can always scrap your car and buy a bicycle or walk, but billions all around the world aren't going to.
Just a thought, anyone on here has already swapped an internal combustion engine for an electric?

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Diesel vs. electric...

That wouldn't have happened to a Tesla!

It would have been long gone!

I guess what I was trying to say is that we choose or are lead to believe in certain things.
Even though we all know there are too many cars, producing too much harmful emissions, we'll choose this one because it has a device (that may of may not work very well), so we're lead to believe we'll only add "this" much to this massive problem!
Where in reality, it's a tiny drop in all the oceans and seas put together and if you were that concerned, you wouldn't have one.

My bugbear at the moment is this plastic carrier bag tax.
5p will not sort out all the damage they have caused and will continue to cause for years to come, it won't stop people using them either.

We're just lead to believe the 5p is going to help someway, it's a slight rap on the knuckle for being naughty and using one to make us feel better!

It's just a ploy to make us feel like we're contributing, while filling a pocket somewhere.

So why not ban them completely?
There are viable alternatives after all and most are just as cheap.
But no, put your hand in your pocket, you'll feel better!

You can see where personal transport is heading.
You'd like to think they'll be a break through, where free, clean, limitless power will move us around where ever we want? Hardly!
What about limiting what we have, say carbon tokens so we all get a share of the limited resources that are left? Blah!
What about being lead to believe paying more tax will prolong these resources and make burning them safer and cleaner? Bingo! We have a winner.

The sooner we subjugate those that live on top of it and the quicker we burn it all, the less "fines" we'll pay for using it and the sooner we'll get used to not having it.
Only then will a proper alternative be found.