STI Rod knock sound?

Discussion in 'Modifications And Maintenance' started by Rudy, Jan 1, 2012.

  1. Rudy
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    Rudy Member

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    Hi there, looking for some advice. I have a strange noise coming from what sounds like the driver side of my engine. I don't know very much about rod knock, lifter knock etc so I am hoping someone can explain to me exactly what rod knock on subarus sounds like? I've watched some videos but am also curious about the correlating symptoms - things like when the noise occurs, when it would be absent on the tach, idle, neutral etc.

    I will go through the symptoms of what I'm hearing but I'd like to hear how people describe rod knock and lifter knock first. Thanks for your help. I have to drive 1k miles this week and I'm freaking out.
     
  2. Ronnie@RSmotors
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    Ronnie@RSmotors Well-Known Member

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    Drain your engine oil in a clean pan and look for bearing material.
     
  3. Rudy
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    Rudy Member

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    I just had the oil changed last week, they didn't mention anything, but then again they probably just drained it in a giant collector. I don't see any flakes when I check with dipstick.

    FML. Dealership doesn't have any appointments until Wednesday. I have to leave Tuesday morning at the latest. FMLFMLFMLFML
     
  4. bikerboy
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    bikerboy Subie GOD Staff Member

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    Your not planning on driving your car are you? The longer you drive it the worse it will get until it stops running with or without a hole in the block if it is rod knock.
     
  5. Rudy
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    Rudy Member

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    I'm not sure what choice I have, aside from trading it to a dealership for a beater of equivalent value, in which case I'd be losing equity...I guess that's something I will need to explore in the morning. This isn't a trip I can cancel or delay. I absolutely have to be 1k miles from here Thursday morning. FML.

    Here's a description as best as I can put it into words-

    It sounds similar to( ) , but does not sound off until about 2.8-3k RPM and I can't really replicate the sound at idle/neutral like the video. I haven't had a chance to listen to it while outside the car, but when I do(tomorrow), the noise is far less noticeable in neutral than when in gear driving. Much like I've read on some other sites, the noise drops off when shifting, getting off the accelerator. It also does not seem audible under high boost. If I can hearing it at 3k RPM in 4th gear but then smash the gas it goes away. If I am in sustained cruise, say 5th gear @ 45 MPH, less than 3k on tach the noise is not audible. The noise is however audible if I were to cruise in say 4th gear at 45 with the tach above 3k. It is much more difficult to tell if the noise is audible at freeway speeds because of road noise, but it certainly isn't as loud as when accelerating past 3k at lower speeds if it is there at all. To me it sounds like a malfunctioning BOV that flutters in accordance with tach/acceleration - not audible from 0-3k RPM but audible for the short time I'm above 3k before shifting. Obviously the sound is quite different than any BOV flutter. There are no metal flakes or evidence of material in the oil at this point, though I haven't taken off the pan.

    What do you guys recommend I do? I can't take it to the only Suby dealer in town(where I am) because they are booked until Wednesday as I previously mentioned. I might take it to a local Honda/turbo shop, but even if I determine without question that it is knock I'm not sure what time/money I have to fix it at this point. I know knocking is extremely unpredictable and structurally dangerous and the thing could explode in 10 miles or 10,000. Am I out of my frickin mind to even consider trying to drive it? Not sure what else to do FML.
     
  6. idget
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    idget Want to pokéman? PM ShortytheFirefighter Staff Member

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    Are you away from home now and driving home tuesday or something? If so cant you rent a uhaul and tow it? If at home and you can leave the caruntil you get back in town to deal with later, rent a car, take a bus, buy a plane ticket etc...

    Where are you located?
     
  7. Rudy
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    Rudy Member

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    I'm in Las Vegas driving to Texas...wont be coming back for over 6 months so I can't rent. Hadn't thought about Uhaul, I'll have to check that out.
     
  8. idget
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    idget Want to pokéman? PM ShortytheFirefighter Staff Member

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    Look into long term parking at las vegas airport. Assuming you cant get someone to look at it before you leave vegas and cant take it with you, store it until you can take care of it. Or drop it off at a shipping company, send it home, and deal with it later.

    There has to be a few subaru "tuner" shops in the vegas area.
     
  9. Rudy
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    Rudy Member

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    I would do that but I need a car where I'm going and have a car full of **** that needs to go with me.
     
  10. idget
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    idget Want to pokéman? PM ShortytheFirefighter Staff Member

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    So rent a car when you get there, ship your ****, store the car. Either way you have several options and now you're starting to sound more and more like a drama llama.

    We're talking about a worst case scenario where you pay a few hundred bucks and spend a few hours planning/shipping/storing tomorrow vs grenading your motor and being out $3-8k to get it back on the road... A best case scenario where you find a shop tomorrow, tow it there, and find out it's nothing... Or something in between.

    Anyway, good luck. If you take anything away from this thread I hope it's bikerboy's advise to not drive it until someone can properly diagnose whatever is going on.
     
  11. Rudy
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    Rudy Member

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    Dealership sqeezed me in, quoted me new short block + components. Left with a black '11
     
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