LSPI problem: potential engine blow up

Discussion in 'Fiesta ST Chat and Discussion' started by FiST_To_The_Clutch, Dec 7, 2015.

  1. Hello,

    So came across this video this afternoon, and it sounds pretty scary. The question I have is when it is good to just keep going uphill pushing on the gas a little and when it is time to downshift? :(



    Thanks
     
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  3. Smokin

    Smokin Active Member

    total bullshit but you should keep the engine revs >2500 and run 93 octane.
     
  4. reddog99

    reddog99 Active Member

    It's obvious from listening to him that he doesn't know anything about what he's talking about. He's just parroting things he's heard from other people who also don't know what they're talking about.

    It sounded to me as if he had carbon buildup that the pinging knocked loose.

    There I go! Another uninformed opinion! :woot:
     
    marc89gti and Smokin like this.
  5. Steven Shattuck

    Steven Shattuck New Member

    my knock sensors go off when i apply anything more than 1/8th throttle in 5th and 6th gear and between 1,500 and 2,500rpm.
     
  6. Zormecteon

    Zormecteon Active Member

    Is that on 93 octane fuel? Do you have a tune?
     
  7. Steven Shattuck

    Steven Shattuck New Member

    i have noticed this on 91 octane, (Because thats the best i get out here in AZ) on cobb stage 0, stage 1 and a bit less with a protune, but still notice it.
     
  8. Well here in CA we have a bit of a crappy gas so max I can go is 91 octane which is the only gas my car has ever seen and tasted since birth (at least dealer told me they put 91 for me when I was purchasing it). I'll only put 91 myself, and if the prices go way up I'd rather walk than put anything lower than 91 in my FiST.

    As for the knocking sensor: is it aftermarket sensor? I do not hear anything knocking/pinging at all, and sometimes I give it like maybe 1/4th of the gas while in 5th/6/th gear on the freeway when rpm are slightly above 2,000 and it accelerates and handles just fine, never noticed anything particularly unusual and I do drive with no music on for now trying to listen to the car and noises it makes. Hmm that's alarming to me :/
     
  9. Smokin

    Smokin Active Member

    Never had a problem with knocking so I tried again after this first post on the highway. 60 mph is 2300 rpm. Floored it in both 5th and 6rth gears and heard nothing. I suppose that's what knock sensors are for, you think? As well as variable valve timing? The ECU?

    Of course you don't want to lug an engine, but a 1600cc engine is hard to lug. First of all at 2300 rpm there's not much air coming in or going out so the turbo is not spinning up and won't until rpm increases. I'm sure you can find those dyno graphs on here somewhere, but I doubt there's much torque at 2300......
     
    Last edited: Dec 16, 2015
  10. Can anyone please clarify what sound a knocking sensor would make? I've never dealt with one, and never heard the sound it's supposed to make. Also where would the sensor (or sensors, if there are more than 1) be located on FiST so maybe I can listen in that area while the car idles/drives?

    Thank you.
     
  11. Zormecteon

    Zormecteon Active Member


    It's called PING. It sounds like that.. .It's easy to hear if it's happening, and you're correct, the knock sensor should prevent it. ..

    Soooooo.... If you shift at the lowest point that the shift light illuminates, you'll notice it's about 1800 rpm, which gives 1500 rpm in the next higher gear. I'm thinking therefore that you most likely shouldn't run the car below 1500 rpm for fear of lugging the engine, which in when pre-ignition is most likely to occur. Don't run full throttle below 1500 rpm (in any gear) and all should be fine.
     
    FiST_To_The_Clutch likes this.
  12. But do you know where the sensors are located on FiST (if it even has any), and how many of them?

    And yeah I typically don't go lower than 2000 rpm in any gear normal city/highway driving (meaning I never put more than maybe 1/6 of the gas), and sometimes I go slightly below 2000 in 6th when cars are slowing down ahead but when I accelerate I use maybe 1/10th of a gas. If I need to go faster I always downshift (probably straight to 4th sometimes).
     
  13. reddog99

    reddog99 Active Member

    Actually, the ST is a mini torque monster. The chart I have shows over 200 ft/lbs from 1900 rpm to about 4500 rpm.

    I ran regular (87 here in California) in my ST for a long time (until the prices fell earlier this year, then I had no excuse to be cheap). I would occasionally hear some pinging, but certainly never enough to be worried about. I also commonly floor the throttle at speeds less than 60 in sixth when the traffic demands it. Again, never any pinging. The car just pulls ahead.

    2014 Fiesta ST dyno test.jpg
     
    Last edited: Dec 18, 2015
  14. Zormecteon

    Zormecteon Active Member

    I don't know where or how PING is detected. It's not a new technology, tho. It was first done by SAAB on their turbo cars in the 80's. They were the first ones to figure our how to make the turbos come on at lower speeds to give bottom end torque instead of just a BANG of power at the top end. I believe that the "listener" adjusts advance thousand of times a second. ...

    If you never give the car more than half throttle tho you aren't getting the best possible fuel economy, ... not that that's why we buy these cars. .. interestingly enough, a heavy foot (and shifting at a low rpm (like 2000) will return better fuel mileage... a light fight and shifting at 2000 rpm will get you worse economy than a heavy one shifting at 5000 rpm...! It's not what they teach in driver's school or preach incessantly, but studies show....


    Ok so I just looked up "knock sensor location" on google. .. you can too.. lower engine block..
     
    Smokin likes this.
  15. yeah I often accelerate hard up to 3500-4000 revs during 1st, 2nd, 3rd, 4th gears, but not using full throttle, maybe at or around 3/5.

    Thank you everyone for help!
     
    Smokin likes this.
  16. marc89gti

    marc89gti Active Member

    Like others have said this guy has no clue what he is talking about, he's trying to mimic what others have said but truly doesn't fully understand what he's talking about. In the video I swear he talks about how on the FiST forums lots of people have reported engine or turbo failures. Again this is the first post I've seen about this issue and usually troll around all three major FiST forums and haven't read one thread about engine failure or turbo failure due to this.
     
    Smokin and FiST_To_The_Clutch like this.
  17. reddog99

    reddog99 Active Member

    I once saw someone's signature in an email that said, "The irony of the Information Age is that it has given new respectability to uninformed opinion.". It seems to fit that video pretty good. :)
     
  18. marc89gti, can you name those three major FiST forums please? I'd like to browse through them some time. Thank you!
     
  19. marc89gti

    marc89gti Active Member

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