Why does my car knock so much in the 2-4k range?!
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Registered User
Joined: Apr 2007
Posts: 927
From: Az
Why does my car knock so much in the 2-4k range?!
It's starting to really **** me off. I have pulled my timing tables well below the stock tables and that isn't right in a cammed car. I've pulled a significant amount and it goes away, but why do they have to be SO DAMN LOW!? What's the deal? Anybody have any insight?!
Registered User
Joined: Aug 2011
Posts: 72
Re: Why does my car knock so much in the 2-4k range?!
Without details of the motor we cant answer.
Factors that increase chance of knock:
Spark plug heat range
ignition timing
Fuel Octane
Oil Consumption in cylinder
Piston surface quality (detonation damage leaves sharp edges that form hot spots)
Compression ratio
intake air temp
Knock sensor failure
forced induction
Have you pulled your plug to see what they look like? if your raising the timing without tunign based on the plugs then your takign a huge risk. A wideband is great but its not a catch all tuning device.
Terry
Factors that increase chance of knock:
Spark plug heat range
ignition timing
Fuel Octane
Oil Consumption in cylinder
Piston surface quality (detonation damage leaves sharp edges that form hot spots)
Compression ratio
intake air temp
Knock sensor failure
forced induction
Have you pulled your plug to see what they look like? if your raising the timing without tunign based on the plugs then your takign a huge risk. A wideband is great but its not a catch all tuning device.
Terry
Thread Starter
Registered User
Joined: Apr 2007
Posts: 927
From: Az
Re: Why does my car knock so much in the 2-4k range?!
Without details of the motor we cant answer.
Factors that increase chance of knock:
Spark plug heat range
ignition timing
Fuel Octane
Oil Consumption in cylinder
Piston surface quality (detonation damage leaves sharp edges that form hot spots)
Compression ratio
intake air temp
Knock sensor failure
forced induction
Have you pulled your plug to see what they look like? if your raising the timing without tunign based on the plugs then your takign a huge risk. A wideband is great but its not a catch all tuning device.
Terry
Factors that increase chance of knock:
Spark plug heat range
ignition timing
Fuel Octane
Oil Consumption in cylinder
Piston surface quality (detonation damage leaves sharp edges that form hot spots)
Compression ratio
intake air temp
Knock sensor failure
forced induction
Have you pulled your plug to see what they look like? if your raising the timing without tunign based on the plugs then your takign a huge risk. A wideband is great but its not a catch all tuning device.
Terry
ignition timing less than stock
Fuel Octane 91
Oil Consumption in cylinder dunno
Piston surface quality (detonation damage leaves sharp edges that form hot spots) Dunno. Looked fine last I saw them.
Compression ratio stock.
intake air temp 100'
Knock sensor failure don't know
forced induction No
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Posts: 71,110
From: Hell was full so they sent me to NJ
Re: Why does my car knock so much in the 2-4k range?!
If you had a knock sensor failure, you would have a code. Has the knock sensor ever been changed? If it's overtightened it could cause a problem.
Check for oil in the hose from the passenger valve cover to the throttle body.
Add high coolant temp and lean A/F ratio to the list above.
And you are saying the only mod is a cam?
Check for oil in the hose from the passenger valve cover to the throttle body.
Add high coolant temp and lean A/F ratio to the list above.
And you are saying the only mod is a cam?
Thread Starter
Registered User
Joined: Apr 2007
Posts: 927
From: Az
Re: Why does my car knock so much in the 2-4k range?!
80'C coolant. A/F has more fueling in that area than anywhere else.
Definitely not. Cam/1.6s/tune/LPP TDs/etc.
Registered User
Joined: Aug 2011
Posts: 72
Re: Why does my car knock so much in the 2-4k range?!
Knock sensors can go bad without throwing codes.....dont believe me....its true. Just go hang out with the mitsu guys for a day.
Take the car out and spend some time in that RPM range and shut it down right in front of your house. Cruise it into the driveway and pull one of the inside plugs (3/4/5/6). How many threads from the CC are dark/dry looking and the rest will look clean/shiny. Where is the timing mark on the strap?
If you have anti-sieze on the plug, you will need to clean it off, clean the threads off in the head and try again. You can let the head cool before you reach in but do not let the car idle as it will throw off the reading on the plugs.
Take the car out and spend some time in that RPM range and shut it down right in front of your house. Cruise it into the driveway and pull one of the inside plugs (3/4/5/6). How many threads from the CC are dark/dry looking and the rest will look clean/shiny. Where is the timing mark on the strap?
If you have anti-sieze on the plug, you will need to clean it off, clean the threads off in the head and try again. You can let the head cool before you reach in but do not let the car idle as it will throw off the reading on the plugs.
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