How do you diagnose a knock WRX?
Rod Knock Symptoms: Subaru WRX The knocking will sound very metal on metal. Almost like someone is beating your WRX’s engine with a hammer. The knocking sound is usually the worst at idle, or when backing down off of the gas. With a rod knock, if you drain your oil you should notice metal shavings.
What causes knock in WRX?
Detonation Knock Most commonly, this is caused by using fuel with an insufficient octane rating for your car. If your vehicle requires premium fuel (such as a turbocharged Subaru WRX), this kind of knock can be caused by accidentally filling up the vehicle with regular grade fuel.
When should I be concerned about feedback knock?
In general, we consider Feedback Knock Correction ~-2.5 degrees or less to be “normal” and not of major concern. If DAM is below the ideal value and there are corrections beyond -2.5, this is good reason for further inspection.
Is fine knock learn bad WRX?
Almost completely safe to say you’re fine, bad gas and/or false knock. Our cars are very sensitive to these things. Just get your gas tank low, fill up with reputable fuel, and your DAM should learn itself back up anywhere from hours to a week from now.
Is knock bad WRX?
Feedback knock is what your sensor registers. Events of -1.41 to -2.81 are normal cruising events. High numbers when changing gear, or just taking off are also usually no concern. You begin to be concerned when you see knock events -2.8 or higher when at WOT.
What is bad feedback knock?
Why is my fine knock learning?
Fine Knock Learning is learned (and thus applied) for specific ranges defined by load and RPM; once a correction value has been learned into a particular range, it will be applied whenever the engine is operated within that range.
Should I worry about fine knock learn?
Under a quality tune, you should therefore NEVER have any Fine Learning Knock Correction. If you do experience it, it’s likely because you have too much timing, or your AFR is off and you’re running a bit too lean. In your case it looks like this happens as your turbo is spooling.
What kind of noise does an engine spark knock make?
Engine spark knock sounds like a metallic knocking; pinging or rattling noise coming from your engine. Engine spark knock is usually heard during moderate to heavy engine acceleration.
How is fine knock learning learned in Subaru?
Fine Knock Learning is learned (and thus applied) for specific ranges defined by load and RPM; once a correction value has been learned iinto a particular range, it will be applied whenever the engine is operated within that range.
How does feedback knock correction work on a Subaru?
Feedback Knock Correction is a real-time timing correction the ECU makes based on a perceived noise. The ECU immediately pulls timing (the amount of the Feedback Knock Correction value) and adds timing back (value rises to 0) assuming no further noise is detected.
What causes a false knock on a Subaru engine?
The Subaru knock detection system tends to err on the side of caution. This makes it common to see “false knock.” False knock occurs when the ECU corrects for a knock event but the noise registered is due to other noises that aren’t necessarily detonation or harmful to the engine.
What should the knock value be on a Subaru WRX?
If this value is anything less than ideal, it’s a quick indicator something isn’t right (unless immediately following an ECU reset/reflash). On an 02-05 WRX the values will range from 1 to 16, 16 being ideal. On all other Subarus, the value is expressed as a decimal from 0 to 1, the ideal value being 1.
Fine Knock Learning is learned (and thus applied) for specific ranges defined by load and RPM; once a correction value has been learned iinto a particular range, it will be applied whenever the engine is operated within that range.
Feedback Knock Correction is a real-time timing correction the ECU makes based on a perceived noise. The ECU immediately pulls timing (the amount of the Feedback Knock Correction value) and adds timing back (value rises to 0) assuming no further noise is detected.
The Subaru knock detection system tends to err on the side of caution. This makes it common to see “false knock.” False knock occurs when the ECU corrects for a knock event but the noise registered is due to other noises that aren’t necessarily detonation or harmful to the engine.