1. Introducing the smashing new Team FIAT T-Shirt !! To order yours click here : Team FIAT T-Shirt

Regarding revving the engine

Discussion in 'Engine Compartment' started by drgopusankar, Apr 16, 2012.

  1. hello friends,

    After reading the posts , I used to rev the engine occassionally as it is good to throw off the carbon building up in the system.. What I usually do occassionally is to rev her upto 3000 rpm while running in second and third gear for a few meters. But today a friend told me that it is of no use..rather you should rev her while idling the engine while pressing the clutch... please make clear how we should rev the engine?
  2. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    A big NO NO.

    EGR valve etc can be cleaned at the TASS. The catalyst just after the turbo needs a good long blast on the highway to burn off the deposited soot. Apart from that just drive it normally and avoid lugging as far as possible.

    Cheers.
  3. dear gurjinder,

    so is it ok to blast her for a few meters in second or third gear upto 3000 rpms..as I do.. please suggest your ideas..
  4. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    It's not gonna solve any purpose, mate.

    To burn off the carbon in the catalyst , you need a spirited drive over atleast 10km's IMO. A few metres won't even heat the catalyst to the required temperature. Avoid lugging as far as possible. That's it.

    Just one of the drawbacks of the "Green" technologies. Thank God we don't have DPF's yet.

    Cheers.
    1 person likes this.
  5. sungoa2010

    sungoa2010

    Messages:
    2,878
    Goa
    Gurjinder, Can you explain little further about the problems associated with lugging.
    Thanks in advance.
  6. What about Liva/Etios/Innova D4-D I think they have particulate filters, how MJD is surviving in European emission laws with out them?
  7. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    Sat, i don't think any of the above mentioned cars have DPF's. They would all be having the common catalysts. I have heard some top of the range diesels from MB, BMW, Volvo etc have DPF's installed already. The Indian Emission requirements are not that strict yet to demand DPF's from cars.

    In Europe, some/most versions of the Multijet have the DPF as well as catalyst . DPF and the catalyst are two separate systems.

    DPF is the scarier version of the catalyst. :)

    x-x-x

    Sungoa,

    In short , lugging is us forcing the engine to operate outside of it's comfort zone. In today's ECU controlled engines with Anti-knock control , we don't feel knocking as a result of lugging as we used to, but that should be no reason for us to lug the engines.

    It can lead to faster wear of the main bearings, inefficient combustion ( more soot in exhaust of diesel engine), more stress on drivetrain components etc .

    Cheers.
    Last edited: Apr 17, 2012
    2 people like this.
  8. Gurjider Sir,

    here is extract from carbibles about D-4D
    "Old-school diesel engines used to sound like tractors when you started them on a cold morning, and they used to spew particulates out of the exhaust to the point where the back of the car went black. Newer generation diesels start much less noisily but for the most part still have some issues with particulates in the exhaust. Toyota claim to have solved this with their D-Cat and DPNR system. D-Cat stands for Diesel Clean Advanced Technology and DPNR stands for Diesel Particulate NOx Reduction. The operating principle is fairly sound. D-Cat is an advanced computer-controlled system for cleaning diesel exhaust gasses which relies on the DPNR catalyser. This is a combination of particle filters and normal gas-reduction catalysing metals that remove particulates, sulphur dioxide (SO2) and nitrogen dioxide (NO2) from the exhaust gasses. A sensor measures can tell when these filters are nearly full at which point a fifth diesel-injector sprays a little fuel directly into the exhaust system. Combined with the exhaust gas recirculation system, this results in all the collected pollutants being burned off, cleaning the filter in the process. DPNR requires ultra-low sulfur diesel (ULSD) to work properly.
    Shortly after this system was launched on the D-4D engined 2.0litre Toyota Avensis, the complaints started to come in. Notably, Dutch car magazine AutoWeek (issue 42 / 2006) exposed the problem when their DPNR-equipped Avensis started driving around with a huge cloud of white smoke pouring out of the exhaust. They weren't the only ones to have this problem. Hundreds of complaints were filed in Germany and other European countries for the same thing. The problem was that the D-Cat/DPNR system needs to 'regenerate' as described above. The particulate and gas filters are cleaned via a combustion mechanism in the exhaust, but this only happens at speeds below 160km/h (99mph), and takes about 20 minutes each time. In Germany especially, where they still have sections of unlimited-speed autobahns, people had been driving well over that speed for miles on end, then stopping and turning the car off, only to repeat the cycle twice a day during their commute. When this happens, the DPNR system never gets time to regenerate normally and the particle filters become clogged and the DPNR system forces a clean cycle to happen. This forced combustion results in white smoke as there are too many pollutants trying to be burned off at the same time. And not just a little white smoke. In the AutoWeek test, they thought their Avensis was on fire it was trailing so much smoke. Toyota promised to sort this problem out with an improved version of D-Cat fitted to the higher-spec 2.2litre engine.
    As of 2011 there wasn't much talk about this any more although there is still reference to the problem in a Toyota TSB (White Smoke From Exhaust, DNPR Only)
    "

    Read more: Car Bibles : The Fuel and Engine Bible: page 1 of 6
  9. sungoa2010

    sungoa2010

    Messages:
    2,878
    Goa
    Thanks Gurjinder. Outside comfort zone is applicable to low speed in higher gear as well as high speed in lower gears. Am I correct?
  10. gurjinder

    gurjinder Staff Member Janitor

    Messages:
    3,989
    Punjab
    Sat sirji, i was talking about the Indian Etiosh/ Leeva and Innova diesels. They will definitely not be having any DPF's. Just catalysts. The DPF is a very complex system and the Indian Emission standards do not demand it, yet. Let's see how much more strict the BS5 norms will be.

    Sungoa, revving higher is not a big issue as compared to low revs in taller gears. Engines do like to be spanked once in a while, but not lugged. ::T

    Cheers.
    1 person likes this.

Share This Page