False knock at 2000 rpm?

[Robbks]

Talked to the guys at S-Technic and they suggested ASG as the ASG guys are fully equipped with knock sensing equipment and a dyno.
The STechnic guys are really helpful and knowledgeable though and will probably sort my exhaust mod when ready.

So did they look/ hear the car and give an indication on what it sounded like?
or just give advice over the phone..?

[Sheik Jabooti]

Talked to the guys at S-Technic and they suggested ASG as the ASG guys are fully equipped with knock sensing equipment and a dyno.
The STechnic guys are really helpful and knowledgeable though and will probably sort my exhaust mod when ready.

So did they look/ hear the car and give an indication on what it sounded like?
or just give advice over the phone..?

Nah, just told them I was trying to diagnose a knock sensing problem and they said ASG are better equipped to do it. Apparently they both swing business to each other. Sean at ASG has a good name as a tuner in particular.

I did already drive past ASG to get an opinion, and without fully inspecting it (we only idled and revved while watching the knock sum increment) they reckoned it sounded normal (ie. standard noisy late model liberty 2.5T). Really need to get it onto a dyno and listen with the right audio equipment to be sure.

[KiDo_Tuning]

http://www.romraider.com/forum/viewtopi ... =15&t=8509

Logs are consistent with PFKC, not FBKC.

[Sheik Jabooti]

http://www.romraider.com/forum/viewtopic.php?f=15&t=8509

Logs are consistent with PFKC, not FBKC.

I guess the way to be sure is to change the FBKC increment to a 1.01 (or something) and see if it corrects by 1.01 or the standard 1.41? If it changes by 1.01 then its FBKC, if not then its coming from the newly discovered PFKC table.

[KiDo_Tuning]

Correct

[Rome_BRZ]

Geez lucky you didn't go and sell your car!!

[bass_straitener]

Geez lucky you didn't go and sell your car!!

Interesting that his tuner suggested he sell as danger was imminent.

BTW David your LV looks spot on.

[Sheik Jabooti]

Geez lucky you didn't go and sell your car!!

Interesting that his tuner suggested he sell as danger was imminent.

BTW David your LV looks spot on.

Cool, nice to know the LV looks normal. As for the PFKC, yet to be proved. I will figure out how to change the increment and give it a go I suppose. If anyone know exactly which table I'd appreciate the tip. I remember reading a forum on it somewhere...just got to find it again.

And as for selling the car...yeah I thought that was a bit OTT. Best to get to the bottom of it first. Still trying to get through my tank of octane boosted fuel before taking it to ASG and seeing if they can hear any real knock.

[west_minist]

Geez lucky you didn't go and sell your car!!

Interesting that his tuner suggested he sell as danger was imminent.

BTW David your LV looks spot on.

I recommended to him to sell if it becomes a problem to diagnose as he seems frustrated.

If the noise is due to the valve train and he does not want to go that far, tell me...we are all owners. If you do not want to spend a large cost pulling down, changing parts, whats next?

If the car is literally not knocking, but the sensor is reporting noise and causing the car to pull timing, then there is an issue to resolve, which is most likely mechanical. Now one can compensate and change variable to make the car not detect, but that is compensating for a steadily growing issue that you are ignoring.

Some statements are taken out of context and one must understand why some statements are made, even when not palatable.

[west_minist]

http://www.romraider.com/forum/viewtopic.php?f=15&t=8509

Logs are consistent with PFKC, not FBKC.

I guess the way to be sure is to change the FBKC increment to a 1.01 (or something) and see if it corrects by 1.01 or the standard 1.41? If it changes by 1.01 then its FBKC, if not then its coming from the newly discovered PFKC table.

Sheik,

this will be my last response on this matter, as I have posted in another forum you have.

Changes those setting will affect everything else.

THe car will not put those in FLKC, due to setting in the rom which you can change on your own.

My question to you, why do this when the car definitely is getting down and clearance tolerances may need to be check. For example, if your shims are getting worn, just get them replace. SOmetimes these shims can drop out and cause damage. You could always try a thicker oil and see, but the best resolve, have a good mechanic run through the engine. It will cost some money, but at least the car with over 100 000km will be getting a good bill of health certificate

[Sheik Jabooti]

http://www.romraider.com/forum/viewtopic.php?f=15&t=8509

Logs are consistent with PFKC, not FBKC.

I guess the way to be sure is to change the FBKC increment to a 1.01 (or something) and see if it corrects by 1.01 or the standard 1.41? If it changes by 1.01 then its FBKC, if not then its coming from the newly discovered PFKC table.

Sheik,

this will be my last response on this matter, as I have posted in another forum you have.

Changes those setting will affect everything else.

THe car will not put those in FLKC, due to setting in the rom which you can change on your own.

My question to you, why do this when the car definitely is getting down and clearance tolerances may need to be check. For example, if your shims are getting worn, just get them replace. SOmetimes these shims can drop out and cause damage. You could always try a thicker oil and see, but the best resolve, have a good mechanic run through the engine. It will cost some money, but at least the car with over 100 000km will be getting a good bill of health certificate

Ed, Thanks for the explanation and I appreciate the time and effort you've put into trying to figure this out...you've been very tenacious and persistent which is greatly appreciated. I agree that the car needs to spend some time with a good mechanic to figure this out...unfortunately it will cost me $$ to get to the bottom of it. And this is for a problem I didn't even know I had before connecting a tactrix cable to the odb port The FBKC is only intermittent and never lasts more than a few seconds before decaying away. I was excited at putting some hard saved money to mods and tuning...now I'm just throwing it at mechanics to find a intermittent phantom knock issue

And just for clarification the cars only done 40,000km (not 100) of normal city driving, so shouldn't be suffering from too much wear I hope.

[west_minist]

Ok. I look at the log. I sent you an email.

In essence, if the sensor is secured properly, once the car stays in a zone too long under load, especially 5th gear around 60-75kph, then she doesn't like it. You have pinging in low gears just into boost and I can understand that due to AFR and cl-ol. But we did work on that before and it hold a tab and came back.

I am really feeling and its only speculation.

1) Piston ring land issues. You may be finding a little more oil in the intake and intercooler due to a little more engine blow-by from the crank case
2) Piston wrist pin movement
3) Valve clearance issues and possibly some valve leakage which could show up in a compression test
4) And maybe the list goes on

The fact is, it will involve a closer look by an experience trained mechanic and especially one who works on modded engines, even building them.

Once can compensate in tuning and try to turn of the warnings. But is this resolving the issue? NO

Like I said before and I know this from customers. When a car is new and you have an issue that grows and you feel it more, it frustrates the you and when he/she keeps running around to get it solve and no one is taking it serious or just don't know what it is or you have to spend money to really find out what it is, then you reach a point where you just live with it or you sell. Its sad, but its reality. Sorry.

I hope you get it resolve for a peace of mind.

[west_minist]

Yeah I know. When I drive my car, I feel a little flat spot or flat spots. I just drive through them. I have a 2000 Impreza 2.0R which I love a lot.

Boy.....when I put the cable on and I see why I feel what I feel, I don't want tot drive her any more. Sometimes I don't even hear her pinging, but it worries me sometimes she will just had enough one day. An you know what???? she is a Auto and pinging is around 1800-2600rpm. lol.

One thing I have, my shim on #4 piston and I think on the intake is slack and did fall out one time when my timing belt was change. Good thing is that was car was not started.

I can tell you, sometimes the car just feels dead for no reason. Regardless of race gas or racing gas concentrate, she just feels dead and another moment great. I just got to the point, I live with it. It keeps me out of trouble.

[Sheik Jabooti]

*****************FINALLY SOLVED AND FIXED*************************

So after months of chasing this one, Matt from Kido Tuning solved it in 5 minutes. It turned out to be exactly his guess - WasteGate chatter. Here is his expert explanation for anyone who has a similar issue:

Quote Matt:
"It was a combination of the intake AVCS causing lean spool, which generates a lot of exhaust heat(shown in the front O2 sensor resistance) in an attempt to get the engine spooled faster(yet mine spooled faster without it ) and that heat was pushing on the wastegate flap and making it chatter against the turbo."

"WG chatter is the cause, hence why it only occurred at one point and why fuel or timing would not affect it When I pulled timing, it made it worse as it made more heat(more unburnt fuel in exhaust) and in the same breath, more fuel made it worse as it was again, more fuel in the exhaust. So can be diagnosed as a weak WG actuator which is why the mechanics could not hear the knock"

[west_minist]

*****************FINALLY SOLVED AND FIXED*************************

So after months of chasing this one, Matt from Kido Tuning solved it in 5 minutes. It turned out to be exactly his guess - WasteGate chatter. Here is his expert explanation for anyone who has a similar issue:

Quote Matt:
"It was a combination of the intake AVCS causing lean spool, which generates a lot of exhaust heat(shown in the front O2 sensor resistance) in an attempt to get the engine spooled faster(yet mine spooled faster without it ) and that heat was pushing on the wastegate flap and making it chatter against the turbo."

"WG chatter is the cause, hence why it only occurred at one point and why fuel or timing would not affect it When I pulled timing, it made it worse as it made more heat(more unburnt fuel in exhaust) and in the same breath, more fuel made it worse as it was again, more fuel in the exhaust. So can be diagnosed as a weak WG actuator which is why the mechanics could not hear the knock"

My reply was here viewtopic.php?f=18&t=16206&start=45#p272419

Did you solve this weak wastegate actuator that is definitely faulty and stated to be causing such issues?

IN essence AVCS was reduce to close to 0 way below what the car was tuned from Subaru. Ignition was remove to no effected higlighting there was an issue. Fuel was added a bit and afr noted and still issue exist. Therefore the issue was mechanical. I have never see wastegate flutter causing this because this would be fluttering back pressure to the turbo which is pretty small at these boost pressure. This problem could have been fix with knock thresholding, but I was not about making these changes to fix a mechanical issue. You did not stated you heard any boost or turbo flattering noise. If Kido was hands on in this matter being able to see your car personally, then any mechanical issues can be resolved even quicker.

But I am always happen my customers or potential customers are happy with other tuner BUT for me its the principle of how issues are resolve. I will review your email based on my principles for a refund because as we both agree, I spent a long time working with you resolving the small area of pinging.