Excessive spark knock
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Joined: May 2005
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From: San Antonio, TX
It will knock, almost like a stick in spokes at WOT (once it's over 4500 RPM)...some times.
Then it will knock to a lesser degree when under load at lower (2200-2500) RPMs....sometimes.
Usually a jab at the throttle will cause the truck to downshift and the knock will go away.
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Joined: Oct 2006
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From: SE Texas
JL
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Joined: Mar 2007
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From: Pa
It will knock, almost like a stick in spokes at WOT (once it's over 4500 RPM)...some times.
Then it will knock to a lesser degree when under load at lower (2200-2500) RPMs....sometimes.
Usually a jab at the throttle will cause the truck to downshift and the knock will go away.
I get a slight ping in my 04' when the engine is loaded good under 1500rpm. Its a lot easier to hear with the headers on than the stock manifolds. I pretty much exclusively run Sunoco fuel and when on a trip try to also but I really don't notice much of a difference in fuel here. Canada fuel however smells different but still runs good.
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Joined: May 2005
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From: San Antonio, TX
Chevron used to be my brand of choice, but spark knock is the worst with that fuel right now.
Shell is pretty good. Exxon, not so good. We recently got a Texaco in town, might have to try them again. That used to be my brand of choice.
I don't think it makes much of a diffence anymore though. Most of the fuel is delivered to all stations in this areais by MidTex or Coastal, with additives added at the wholesale rack or upon delivery to the in ground tanks.
I mostly try to use a newer station or one that does a lot of business to avoid stale or contaminated fuel.
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Joined: Nov 2003
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From: Oxnard CA
I have a 2000 F250 SD 4x4 automatic and have had the pinging/knocking under acceleration ever since I bought the truck. Recently I had a check engine light with a code P0174 - Lean left bank. I would clear the code and after running the engine for a few minutes the code would come back. One day I heard a hissing/whistling noise from the engine and discovered that the Positive Crankcase Ventilation (PCV) hose, that connects to the intake manifold underneath the throttle body, was cracked. I taped the crack closed, cleared the code and the code didn't come back. My tape-up job didn't last very long so I replaced the hose with a fuel rated 3/4 rubber hose and hose clamped the other end that connects to the hose for the PCV. The other day when I accelerated up a few mountain roads, I didn't hear the pinging/knocking. I'm thinking that the PCV hose line to the intake manifold was sucking in additional air that would cause the fuel system to run lean. Anway... it seems to be working for me. In all my discussions with Ford tech, they never brought up this possibility.
Postmaster
Joined: Oct 2006
Posts: 4,171
Likes: 12
From: SE Texas
I have a 2000 F250 SD 4x4 automatic and have had the pinging/knocking under acceleration ever since I bought the truck. Recently I had a check engine light with a code P0174 - Lean left bank. I would clear the code and after running the engine for a few minutes the code would come back. One day I heard a hissing/whistling noise from the engine and discovered that the Positive Crankcase Ventilation (PCV) hose, that connects to the intake manifold underneath the throttle body, was cracked. I taped the crack closed, cleared the code and the code didn't come back. My tape-up job didn't last very long so I replaced the hose with a fuel rated 3/4 rubber hose and hose clamped the other end that connects to the hose for the PCV. The other day when I accelerated up a few mountain roads, I didn't hear the pinging/knocking. I'm thinking that the PCV hose line to the intake manifold was sucking in additional air that would cause the fuel system to run lean. Anway... it seems to be working for me. In all my discussions with Ford tech, they never brought up this possibility.
JL
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