« previous next »
Pages: [1] 2

Author Topic: knock, knock....Who's there? Knock....  (Read 844 times)

Offline Charn Gill

  • Hero Member
  • *****
  • Posts: 668
knock, knock....Who's there? Knock....
« on: November 17, 2003, 06:05:15 pm »
just a question.
I used to think that it was just a small backfire, but then one day i smoked a nice sized pothole and this backfire kept happening when I would shift from 1st to 2nd.
Its happened before, even when I dont hit things, (usually on cold mornings or when im driving slow)
anyways. i get this "knock" kinda sound from the rear of my car, always thought it was just a small backfire, but sometimes it sounds like its too far into my pipe to be a backfire. So now im thinkin, "could it be knock?" but i thought that only happens a high speeds? something to do with fuel cut? i dunno...
so yeah, happens occasionally on cold mornings and when im driving slow and usually happens when I shift from first to second, just as i let off the clutch....
maybe its something....maybe its nothing....
maybe its everything....... 8)


*edit. Okay I read up on it. so gas quality can make the engine retard thus knocking more. I use 94 octane all the time, what the deal?*
Logged
95 GS-T ** 91 RX-7 ** 94 Civic Hatch. - B18-C ** 07 Dodge Nittro ** 90 Isuzu Impulse RS ** 98 Eclipse GS-T Spyder

We all own DSM's so clearly we like abusive relationships - Rob Armstrong

Offline Wade Carlson

  • Hero Member
  • *****
  • Posts: 1201
knock, knock....Who's there? Knock....
« Reply #1 on: November 17, 2003, 06:28:55 pm »
you can't hear if your engine is knocking when u are driveing it
so its not that
Logged
Had a DSM...........sold it............ never been happier

Offline Charn Gill

  • Hero Member
  • *****
  • Posts: 668
knock, knock....Who's there? Knock....
« Reply #2 on: November 17, 2003, 06:43:05 pm »
really? i thought you could. someone from off this site said you could hear it. (ill keep the name anonymous) but a reputable guy...
Logged
95 GS-T ** 91 RX-7 ** 94 Civic Hatch. - B18-C ** 07 Dodge Nittro ** 90 Isuzu Impulse RS ** 98 Eclipse GS-T Spyder

We all own DSM's so clearly we like abusive relationships - Rob Armstrong

Offline Mike Meron

  • Senior Member
  • Hero Member
  • *
  • Posts: 1632
knock, knock....Who's there? Knock....
« Reply #3 on: November 17, 2003, 07:32:33 pm »
you can hear fuel cut, you cant hear knock unless you hear valve ping which is related to knock and detonation.
fuel cut only happens at high revs
knock can happen at various rpm's due to different variables such as timing and octane of fuel compression and carbon deposits
if youre hearing something its not knock.. maybe unburnt fuel entering the exhaust but could almost be anything
Logged

Offline Travis Merrick

  • Hero Member
  • *****
  • Posts: 2394
knock, knock....Who's there? Knock....
« Reply #4 on: November 17, 2003, 07:40:25 pm »
you may have a crack in a weld in your exhaust, an exhaust leak causes a backfire.  Check your cat.
Logged
2 TSi AWD - 14.2@98mph - RIP

85 SJ413 w/ Toy axles

Offline Robin Toor

  • Hero Member
  • *****
  • Posts: 2473
    • http://bcdsm.labattz.com/Robin%20Ride/featured_ride.htm
knock, knock....Who's there? Knock....
« Reply #5 on: November 17, 2003, 09:26:18 pm »
its guarenteed a back fire.... you cant hear knock.. and fuel cut only happens when you really give it and are at high RPMs... and you can FEEL and HEAR that.... yes true shitty gas can retard the timing, but you still cant hear the knock it makes.... most likely your running rich or something and are having some backfiring....
Logged

Offline Chris Andrews

  • Hero Member
  • *****
  • Posts: 2361
  • Good news Everyone!
knock, knock....Who's there? Knock....
« Reply #6 on: November 17, 2003, 09:43:59 pm »
Quote from: "Charn Gill"
really? i thought you could. someone from off this site said you could hear it. (ill keep the name anonymous) but a reputable guy...


C'mon, spit it out.  Who is it?  So we can laugh at them. :laugh:

....or at least post the thread....

I didn't think there was anybody "reputable" on this board....  You all suck.  :P
Logged
92 TSi  AWD 2.4L Hybrid 12.3@113 SoLDINated!!!!
2008 Toyota Tundra. 5.7L
2012 KTM 350 EXC-F
2008 Arctic Cat M8

Offline Andrew Scott

  • Hero Member
  • *****
  • Posts: 2800
knock, knock....Who's there? Knock....
« Reply #7 on: November 17, 2003, 10:18:27 pm »
When you hit fuel cut, you'll know
Logged
Parked: 1989 240sx - Esso 87 octane, Superstore generic 10w30, Japanese automatic climate control, Pioneer AVIC-Z3 navagation, Tien Flex Coilovers, Poly bushings, R34 Brakes (front and rear), Cusco tri-point strut braces (front+rear), 1998 tail lights, rear+side valance, adjustable toe and camber arms, cusco sway bars, helical rear diff, Volk TE37s - For sale!
Daily: 2008 BMW M3 DCT

Offline John Hartman

  • Senior Member
  • Hero Member
  • *
  • Posts: 17539
knock, knock....Who's there? Knock....
« Reply #8 on: November 17, 2003, 10:39:42 pm »
some people swear that they can hear it.  Personally I don't think so, at least not on my car.  I've heard it on others with quieter engine/exhaust for sure.

It could be something completely different(not monty python either) like a loose heat shield, loose pipe, worn ball joint/ujoint/carrier bearing/cvjoint etc.

Or just your airbags/playstation/subs rattling around in your trunk :P
Logged
91 Eagle Talon TSi 5spd awd.  GT-12, TriFlow Cams, 850s, Tial, JIC, Jackal, sticky rubber.
86 Merkur XR4Ti 5spd, rwd, turbo, 91,381km.  Original paint, heated leather. intercooled, big VAM, Full 3" exhaust, Cossie sway bar, 16" tires.
06 Mazdaspeed6 6spd awd, DISI turbo, heated leather HIDs, Corksport, Cobb, Konig, Centric...
2018 VW Golf Alltrack turbo Tornado Red, 6mt, some free mods

Offline Charn Gill

  • Hero Member
  • *****
  • Posts: 668
knock, knock....Who's there? Knock....
« Reply #9 on: November 18, 2003, 12:19:57 am »
I think that the person who told me was reffering to the fuel cut.
John...hehehe you always raggin on robin.. its funny....dont worry, you can chrome out your car too :)
just start with the blank Cd hangin from your rearview... :wink:

what about "faulty knock" or is it called "fake knock"? whats that about?(cant find it in the vfaq's)
Logged
95 GS-T ** 91 RX-7 ** 94 Civic Hatch. - B18-C ** 07 Dodge Nittro ** 90 Isuzu Impulse RS ** 98 Eclipse GS-T Spyder

We all own DSM's so clearly we like abusive relationships - Rob Armstrong

Offline Charn Gill

  • Hero Member
  • *****
  • Posts: 668
knock, knock....Who's there? Knock....
« Reply #10 on: November 18, 2003, 12:23:02 am »
Quote from: "Travis Merrick"
you may have a crack in a weld in your exhaust, an exhaust leak causes a backfire.  Check your cat.

could be. I know for sure taht I have a nice dent in my oil pan. the guys at MR.LUBE always remind me.
Logged
95 GS-T ** 91 RX-7 ** 94 Civic Hatch. - B18-C ** 07 Dodge Nittro ** 90 Isuzu Impulse RS ** 98 Eclipse GS-T Spyder

We all own DSM's so clearly we like abusive relationships - Rob Armstrong

Offline Andrew Scott

  • Hero Member
  • *****
  • Posts: 2800
knock, knock....Who's there? Knock....
« Reply #11 on: November 18, 2003, 03:31:45 am »
Quote from: "Charn Gill"

what about "faulty knock" or is it called "fake knock"? whats that about?(cant find it in the vfaq's)


phantom knock

its when your engine makes knocking sounds (like lifters, or rattling), but it isn't actual knock. Still, the knock sensor picks it up as regular knock and retards timing nicely for you. Quite annoying
Logged
Parked: 1989 240sx - Esso 87 octane, Superstore generic 10w30, Japanese automatic climate control, Pioneer AVIC-Z3 navagation, Tien Flex Coilovers, Poly bushings, R34 Brakes (front and rear), Cusco tri-point strut braces (front+rear), 1998 tail lights, rear+side valance, adjustable toe and camber arms, cusco sway bars, helical rear diff, Volk TE37s - For sale!
Daily: 2008 BMW M3 DCT

Offline Chris Andrews

  • Hero Member
  • *****
  • Posts: 2361
  • Good news Everyone!
knock, knock....Who's there? Knock....
« Reply #12 on: November 18, 2003, 07:38:00 am »
Real "phantom knock" is actually quite rare.

Almost every single case of phantom knock disappears when race gas is put in the tank.
Logged
92 TSi  AWD 2.4L Hybrid 12.3@113 SoLDINated!!!!
2008 Toyota Tundra. 5.7L
2012 KTM 350 EXC-F
2008 Arctic Cat M8

Offline Robin Toor

  • Hero Member
  • *****
  • Posts: 2473
    • http://bcdsm.labattz.com/Robin%20Ride/featured_ride.htm
knock, knock....Who's there? Knock....
« Reply #13 on: November 18, 2003, 09:26:59 am »
Quote from: "Charn Gill"
John...hehehe you always raggin on robin.. its funny....dont worry, you can chrome out your car too :)
just start with the blank Cd hangin from your rearview... :wink:


 :roflf:
Logged

Offline Travis Merrick

  • Hero Member
  • *****
  • Posts: 2394
knock, knock....Who's there? Knock....
« Reply #14 on: November 18, 2003, 10:05:05 am »
Quote from: "Charn Gill"
Quote from: "Travis Merrick"
you may have a crack in a weld in your exhaust, an exhaust leak causes a backfire.  Check your cat.

could be. I know for sure taht I have a nice dent in my oil pan. the guys at MR.LUBE always remind me.


if its a backfire I almost gurantee it man, mine had a small leak in my cat cause of scraping to much, well let me tell you, I was blasting everywhere I went, sometimes on purpose though  :twisted:
Logged
2 TSi AWD - 14.2@98mph - RIP

85 SJ413 w/ Toy axles
Pages: [1] 2
« previous next »