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EGR Cleaning

Discussion in 'Engine Compartment' started by amolmane, Nov 22, 2010.

  1. Ganges

    Ganges Esperto

    Messages:
    3,123
    Driver Seat _/
    :
    Grande Punto 1.3
    Thanks Amit for sharing.

    if ECU does it job by correcting the other factors, so do we really require EGR cleaning before Engine check light error ?


    EGR cleaning understanding(correct me if i'm wrong) :-
    Now say i'm having clogged EGR valve now due to this ECU comes into picture and adds the correction which results into some more work required by other components as time prolongs(say after 30K Kms) due to over work done by these components the engine behaves sluggishness,with increase NVH levels or say lazy turbo kick-in but completes the given work(for ex :-acceleration,deaaceleration) as per its sweet/lazy time :D ? ultimately the engine performance slows down gradually ? (this is what i felt after cleaning my EGR valve)
  2. redbull

    redbull

    Messages:
    292
    Bangalore
    This is what Siddharth told me too. I asked to get the EGR deleted completely but he told I might get Engine Check Light if I block it completely. He has seen this especially in the VGT 90HP tune. So he did the next best thing which is to close it partially.

    - - - Merged Post - - -

    I don't understand this reasoning. EGR is supposed to be a regulatory addition to the car (like the catalytic converter) to lower NOx emissions and does absolutely nothing to aid the Internal Combustion Engine. Except for some completely unintended additional beneficial side-effects like lowering the exhaust gas temperature which will extend the life of the exhaust valve, turbo and the catcon. EGR in general will reduce engine efficiency leading to some power loss and lower fuel efficiency. EGR gate will close completely on full throttle so as not to hamper engine performance in demanding conditions. Given this, how will a clogged EGR cause sluggishness, NVH or more wear-n-tear? ECU may put up a Check Engine Light when it detects EGR not functioning properly.
  3. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    As it's a remap, can't the EGR be coded out of the ECU? :confused:

    I don't understand EGR's effect on cooling the exhaust temps+turbo as well ( the reason given for not blocking the EGR). A good remap will ensure temperatures stay within limits always.
  4. redbull

    redbull

    Messages:
    292
    Bangalore
    This particular ECU is not a simple ECU and very difficult to confuse it :) That is what I understood from my interaction with Sid. Yes it can be deleted via a remap and workarounds put in place to prevent the CE light and error codes, but it seems the ECU can override this even. This is a work in progress.

    EGR is meant to lower the combustion temperature to prevent formation of NOx and thus the EGT will naturally be lower. This is a side-effect and not something which is engineered. Anyway, whether the EGR is delete or not, maintaining EGT within safe limits is one of the main concern of Sid's remaps.
  5. Italia-Linea

    Italia-Linea Staff Member Janitor

    Messages:
    2,123
    Pune
    The concept is somewhat like this -

    In a combustion chamber fuel burns with the help of air. Now air contains 70% nitrogen and other parts of different types of gases (we learnt in science :)) This nitrogen when burns under high temperatures combine with oxygen and forms very harmful nitrous oxide.

    So engineers thought of some way to decrease the temperature of combustion chambers. Lowering compression ratios reduces performance. So they designed an EGR valve which can recirculate burnt gases. Now you will say how come hot exhaust gas reduces temp. Acutally the exhaust gas temp is lower than combustion chambers and this inert gases absorbs some temp and it does not burn. It reduces some efficiency but there is no other option.

    EGR remains close on idle and opens on part throttle. We have electronic ECU controlled EGR which opens in % under various conditions that ECU computes. In the background very complex calculations run which take signals from lambda sensor oxygen % , loads, maf, map etc etc. EGR valve opens and closes slightly or more depending on voltages sent by ecu.

    If Exhaust gas temperatures are too high due to EGR delete then there may be valve / piston pitting/ corrosion.

    There is a swirl gasket that can be put between the flow. This is a gasket with holes in it which will enable EGR gases to flow under some pressure to that they dont easily soot up. I am going to experiment it when i get some time, will post the results if any.

    In our MJD EGR is water cooled for better efficiency.
    4 people like this.
  6. bhai

    bhai Esperto

    Messages:
    1,185
    Ahmednagar
    Grande Punto 1.3 90 HP
    @ Italia-linea
    Correctly described! One point remained.
    When we put aircon on, egr is closed to maintain drivability of car.

    When EGR is unnecessary open too much exhaust gas enters in combustion chamber.
    Too much exhaust gas means more air in combustion chamber.
    Air-fuel mixture becomes lean. So overheating,knocking & powerloss is there.
    1 person likes this.
  7. Just to add tho the point of discussion 76HP and 90 HP(Punto/linea) uses different ECU.it is easier to disable EGR in 76 than 90HP.
  8. Ganges

    Ganges Esperto

    Messages:
    3,123
    Driver Seat _/
    :
    Grande Punto 1.3
    Then its better to run with a Clogged EGR and comply with the emission norms :confused:
  9. The gist of the matter is kind of right.
    If Exhaust gas temperatures are too high due to EGR delete then there may be valve / piston pitting/ corrosion. this statement is wrong. The EGR valve automatically closes at higher RPM. Where load is highest therefore producing the highest combustion temperatures. The Engine can easily sustain those temperatures without damaging valves / piston etc. So closing the EGR earlier at lower RPM does increase the combustion temperature at that RPM band (1000 – 2300 RPM) but is still below the peak temperature at high load,( 2500+RPM) when you are driving on highway.

    I have seen many cars driven in highway ,may be upto 80% being in better health than cars driven city again 80% of the time. It is easy to disable EGR in DI engined Indica, I see cars are running with two Lakh ODO with no change to Cylinders/Piston/Valve or cam shaft.

    hope this makes sense

    - - - Merged Post - - -

    World is full of choices sir:)
    Last edited: Dec 21, 2012
    1 person likes this.
  10. Ganges

    Ganges Esperto

    Messages:
    3,123
    Driver Seat _/
    :
    Grande Punto 1.3
    i was expecting an technical reply :)

    After reading the discussion i came to know the EGR operation,now i will have options of the choices 'disable it,enable it,how to comply with the norms' :D .
    Its always good to keep our cars clean either interior,exterior or engine compartment or its ancillaries.
    2 people like this.

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