Phantom Knock, Very Frustrating

[GRace]

I'm getting screwed by phantom knock. As soon as I press the throttle any, I get 15-16 degrees of knock retard in park. This happens at any and all rpms no matter the condition, in gear or not. The only time I don't show knock is when the car is idling with no throttle.

I've tried hitting the intake manifold with a hammer and the knock sensor doesn't show anything at idle. But for some reason right when the gas is pressed slightly, 16 degrees retard. I have a new engine with 3g lifters, 8 month old knock sensor from autozone, says mitsubishi on it. I've tried loosening the knock sensor but it didn't help.

I checked the base timing and it lines up perfectly. I do hear some slight chattering in the head but I figure that the lifters will make some noise during operation. My mounts are now filled with window weld and I think that didn't help any.

I set ecmlink to ignore knock until 2500 or more but every time I hit the cutoff, huge knock retard no matter the condition. Any help would be appreciated.

 

[tron2119]

Are you sure you got the right knock sensor? I called up autozone and the said they don't carry a knock sensor for a 6 bolt. Maybe you got a 2g knock sensor? Unless they somehow are available in your area and not in mine. Also someone correct me if I'm wrong....but I believe the 2g KS will plug right into a 1g plug. I THINK. If you somehow did get a 2g KS that's going to be your problem as they are setup differently in the ecu (more or less sensitive...I forget which way it is.) I'd check the part # on it.

 

[GRace]

Are you sure you got the right knock sensor? I called up autozone and the said they don't carry a knock sensor for a 6 bolt. Maybe you got a 2g knock sensor? Unless they somehow are available in your area and not in mine. Also someone correct me if I'm wrong....but I believe the 2g KS will plug right into a 1g plug. I THINK. If you somehow did get a 2g KS that's going to be your problem as they are setup differently in the ecu (more or less sensitive...I forget which way it is.) I'd check the part # on it.

It looked exactly like a 1g knock sensor should, it had goo in the back. Its part number is SU3303 and it had a mitsu sticker on the plug. I might be able to get another on warranty but I'm not sure if the sensor is my problem.

 

[Jankenshank]

Aim asuming that it drives fine with no issues?

the only time i have had that much knock is when my valves were hitting my pistons....

 

[GRace]

Aim asuming that it drives fine with no issues?

the only time i have had that much knock is when my valves were hitting my pistons....

Yes, it drives really good out of boost with the knock being ignored by ecmlink. I've put around 2500 miles on this engine.

 

[tron2119]

Unplug the knock sensor and drive it around on a safe tune. See how she does. It has all the signs of phantom knock.

 

[laserspeeddemon]

No wonder you're red. When the engine retards the timing does it still show knock? It's possible you have a bad knock sensor.

 

[tron2119]

No wonder you're red. When the engine retards the timing does it still show knock? It's possible you have a bad knock sensor.

I didn't say go rip on it. I was refering to Turboglen's post in another thread that the stock knock sensors are basically worthless. "Welll, as many people have pointed out in other places in the past the OEM knock sensor is about equal to or less than the value of a rabbit turd in worth."-Turbglen

I didn't make myself clear enough I suppose.... I just meant unplug it until you get another to replace it so it doesn't keep pulling a shit ton of timing.

 

[GRace]

No wonder you're red. When the engine retards the timing does it still show knock? It's possible you have a bad knock sensor.

Yeah it shows knock until I let off of the gas. Maybe I should order a new one? It has a 2 year warranty through autozone so It won't cost me anything.

 

[red1993gsallmt]

DONT UNPLUG ITTTTT! But make sure its in the right spot

 

[GRace]

DONT UNPLUG ITTTTT! But make sure its in the right spot

Yeah I definately won't unplug it. I would burn the car if the engine blew. I have it pretty close to where the cylinder head meets the block on the back side.

On my old engine, it was closer to the bottom of the block, a lot easier to get to. Where I put it now, I have to take the starter off to get a wrench on it. Does any of that make sense? I have never found a definative answer on where it goes.

Actually, on my old engine, same knock sensor, I could actually tune out small amounts of knock that would pop up here and there. I really need to figure out what hole the knock sensor needs to be in...

 

[AlaskanDsm]

"The knock sensor is lcoated in the engine block directly below the intake manifold." -Haynes Manual

Basically is goes right below the intake in about the middle of the block.

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[GRace]

Yeah that looks like the place I have mine... I was hoping it was something easy like that.

 

[tron2119]

Ya....phantom knock is not going to blow your engine...nope.I stated unplug until you get your replacement and DO NOT drive the balls off it. Why is everyone freaking out. I've done this twice when my KS failed. The car sucked to DD because it was pulling so much timing....for nothing... hence "phantom".

 

[laserspeeddemon]

The problem is "you or I" don't know enough about the car to see if it's really phantom knock. In an extreme case, what if the car is running 10.5:1 compression pistons and running a tune designed for 880cc injectors with stock 450cc injectors.

"Ignoring the problem" that could blow the motor is never a solution, even if temporary.

 

[rowdygst]

i have the same problem, and have gone thru 3 ks and it has not fixed the problem... i had dsmlink timing -10 so it wouldnt knock , if i tried to advance timing alittle bit it would go crazy...

 

[GRace]

The problem is "you or I" don't know enough about the car to see if it's really phantom knock. In an extreme case, what if the car is running 10.5:1 compression pistons and running a tune designed for 880cc injectors with stock 450cc injectors.

"Ignoring the problem" that could blow the motor is never a solution, even if temporary.

I know just about everything there is to know about this car mechanically, that's what makes this so frustrating for me. I'm running 7.8:1 pistons with 660cc injectors. Everything is set up in ecmlink. I'm idling at 14.7:1 afrs. I'm running 91 octane and my iats have been around 45 degrees. Not that it really matters much when free revving at low rpms.

My problem is I am having knock in park. Whether I slam the pedal or barely tap it, it retards a ton of timing at every rpm above base idle. I get that same knock when I drive around.

I'm going to pick up a new knock sensor tomorrow but I don't expect anything to change. I just don't understand how there are so many fast dsms that don't have phantom knock problems like this but mine gives me so much trouble after so much work and money.

 

[tron2119]

I would try another knock sensor, possibly from a friend that is known good. That way you should know if the knock sensor is your problem or if there is a bigger problem.

 

[spoolin ddub]

Did this just start? You say you only see knock when the gas is pressed. Look for when you drive to speed. Does it then show knock upon deceleration with your foot off the gas? If it does most likely your sensor is working. It hears pinging just knot from knock. If it does it in park by just tapping the gas , not good. Sounds like it may be very serious engine noise. Get another sensor asap to verify. Hopefully it doesn't react the same. Even though the car drives well your motor may be hurt.

 

[GRace]

Ok, I got a new knock sensor. I'm not sure if it is an OEM Mitsu sensor, but it looks exactly like some I have seen. I just want to make 100% sure that I am putting the knock sensor in the right place because I have heard different viewpoints on where the best place to put the sensor is.

I have two holes on the block, as in my pic, that would take the knock sensor. Where the sensor is in the pic is where the sensor has been while getting phantom knock. I have heard that it is better to put the knock sensor closest to the combustion chamber which would be the upper hole but the pic from the manual, posted above, shows the sensor in the current location.

Which hole do I need to put the sensor in? I know this is remedial, but I need to cover every possible problem.

 

[turboglenn]

Can you post some logs of driving with it both knocking at off idle like you describe and with it cruising like everyday normal driving would show? That might help a lot for determining what's up, but the OE knock sensors do suck, and i personally prefer system that ignore it as long as i know the engine is in good health and do what i know to be a safe tune for the build on the motor. Then i'll just read plugs and look for other signs of det/pre-ignition when doing pulls on the road or dyno

edit; where you have it is the OEM location, and actually the best place to mount one is down on the "lower deck" of the engine on the same plane with the main bearing journals

 

[GRace]

I made a log, I set the knock ignore to 700 rpms and 0 percent throttle at the beginning of the log. I had to change it to 10% throttle and 1000 rpms to even get the car to move after I pulled out of the garage.

The wideband reading is .2-.3 higher on the log than the wideband is actually reading so subtract .2-3 to get the actual afrs. I just wired in the wideband and haven't calibrated it yet.

I changed the globals around a few days ago to get my afrs in open loop closer to the afr-est and haven't had a chance to compensate much so the tune really isn't right but in closed loop everything should be fine.

The knock is crippling without knock ignore activated. Maybe the log will shed light on a possible problem.

 

[turboglenn]

So far i'm not seeing a lot, the maxoct table has a rather high timing attack rate right off idle which could cause some extra iston slap (as well as what's probably there from age/wear on the engine) I also get some off idle pickup on my J&S which is designed to be very picky about distinguishing real and phantom knock. the idle and off idle goes from 7* to 18* and higher in the very next cells. personally i run a lot of timing at idle and still don't have as much timing as you by 1500 RPM because i could hear it ping at higher levels.

Also, youre settings show the KS shouldn't even be active till over 2700 RPM and 20% TPS so i imagine it's a glitch of sorts. the tohr times i saw knock while at a LOW rpm cruise with a small TPS change also looked like piston slap or picking up noises that aren't in the engine.. knock at those low of levels usually isn't knock but soething else resonating through the engine being picked up by the KS.. if it's not kncking above 3500RPM when you get into boost i wouldn't worry about it and would maybe contact ECMlink and see why it's picking it up when it shouldn't even be active yet.. That s the reason' i'm betting more on a glitch than anything to worry about.. hell, My monitor for the J&S shows me every piston slap in the engine now that i've moved it back to the OEM location instea of on the lower deck plane in the hole that now holds the left CV intermediate shaft (the owner of J&S said this is thebest place to hear true knock as it will resonate through the rods, transfer to the crank and thn to the main journals, best being heard on the same plane as them which is the metal in the area the oil pan bolts to, and why i chose the old location to be where thenow AWD left CV shaft is bolted in.. that was the most reliable place to listen, i got a reading when there WAS knock and non when there wasn't.

Now and in the past with it in the OEM spot i can drive slow in parking lot constantly turning the AC pump on an off with the button on the dash and every so may times it will pick up that clutch noise and pull a full 10* from all cylinders (i have it setup to pull no more than 10* and only from the individual cylinder that knocked (not all 4) but the AC compressor noise will fool it

i'd say you're good to go, how about some 2nd/3rd gear half to full throttle pulls into boost (unless you get crazy knock, but still logs help the most)

 

[GRace]

I think everything is good now. I got a new ecm, which fixed a lot of things. I no longer get the crazy knock right when I press the gas. I get a little bit at low throttle, maybe 4 degrees on and off but I figured that is normal with window welded mounts.

As soon as I can make some wot pulls, we'll see if the knock is really gone.