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CRAZY READINGS: COBB AP V3 is showing all kinds of Knock issues! HELP!!! HELP NOW!!!

8K views 29 replies 4 participants last post by  EJ257 
#1 · (Edited)
So, just as the title says, I'm getting strange readings. I never had a protune done before, I just bolted on some parts and flashed the ECU with the Accessport. :confused:

Vehicle Information:
2008 STi
105, 677 Miles
103, 440 Last Oil Change
103, 879 Spark Plug Change
104, 789 Last Coolant Change w/ Super Coolant (50/50) and Conditioner

-Parts:
COBB SF Intake
NGK Iridium Spark Plugs gapped at .028
Nameless Muffler Deletes

-Tune:
Currently- Stage 1 + SF Intake 91Oct (OTS) [Changed due to issues = temporary fix]
Previously - Stage 1 + SF Intake 93Oct (OTS)
Experimented with Stage 1 Economy Mode (OTS) [had a long trip wanted log changes in MPG, if any]

--------

Background Information:

I took a long trip from Northern New York to Philadelphia, PA (289 Miles) on Stage 1 Economy Mode (OTS) just to see if any changes to MPG would surface... Starting suspect that I am going to regret this decision. :unhappy: So, going down, was no problem at all. Upon coming back up, half way through my trip, I noticed "sputtering" in the sense of a jerking due to a loss of power during acceleration in 5th/6th Gear. Noticed huge drops (increase depending if you perceive negative values) in Feedback Knock (as low as -11.80!!! :unhappy: ) and Fine Knock Learning ( as low as -11.77!!! :confused: ). At one point, the DAM dropped to 0.550!!! I noticed that whenever Boost was being dumped, the FBK and FKL would make those huge NEGATIVE VALUES. I suspected that it was my map and Changed back from Economy Mode to Stage 1 + SF Intake 93Oct IMMEDIATELY!!! :shakehead: I waited around 15 minutes at the toll booth because I was nervous, then pulled off and had very minor "sputtering" instances but not as much instances as huge negative values as before.

As I further did some investigations, I figured it was time to change those Spark plugs. I was right. The old ones were completely brown and had tons of carbon build up. Installed the NGK Iridiums gapped at 0.30 (for longer life expectancy) and things ran smoothly for a few days. Then.... the "sputtering" again. :mad: It caused extreme negative values and I knew that I needed to regap the Plugs to the factory 0.028, I realized that the mistake must have been a foolish move. Damn, I'm starting to second guess everything I'm doing!!! :mad: Upon regapping, I realized that the Coil Pack on Cylinder 1 had loosened since the last Spark Plug Change!! HOW?! Again, my face: :mad: At this point, I'm about to take a sledge to my motor... but wait... that's not what makes a Subaru owner a Subaru owner.... :pray:

So, I fix the gapping issue, and it ran ****ing great for a week! No negative FBK or FKL values lower (or greater, again, depending if you read negative values appropriately) than -2.8. No power losses, neither in 3rd Gear WOT's or Highway Cruising (65 to 78 MPH). Then, the "sputtering, jerking, no-boost-gain-acceleration-that-pushes-you-into-the-seat-feeling, and low rumble (not-as-throaty-or-loud-out-the-rear) noise" came back to rear it's ugly *&^%!#@ head!!! :mad: :mad: :mad: It's about to be a RIP RIP on this motor and my patience for it.... But, again, WWASOD (What Would A Subaru Owner Do?) :pray:

Finally, I give up and read a ton of articles on these extreme negative values from COBB posted on their website that someone transcribed and posted to NASIOC [ Click Here: https://forums.nasioc.com/forums/showthread.php?t=2711703 and do a search/ Find In Page for "extreme negative values" ]. So, it seemed to be a Boost Leak issues.... But, really??? REALLY?! Hmm... :confused:

I called COBB, but they're taking forever to review the email I sent them with the Datalogs and I need answers!!! Recently, the DAM has been dropping and the FKL has been dipping again into the -5 to -9.8 range. :eek3:

I'm going to post the Datalogs and see if anyone can offer me answers, and preferably, SOLUTIONS!!! :pray:

Thanks ahead of time!!!


FILES
WOT 3rd Gear Pull w Low DAM and POS FKL : https://drive.google.com/open?id=0B4draOa__qd7ZUZpbmNTT2hWZnc VERDICT?!- :D
HIGHWAY DRIVING 91Oct w SF OTS Map : https://drive.google.com/open?id=0B4draOa__qd7M3BuOHdxS0FNUXM VERDICT?!- :confused:
Regular City Driving w Jumping FBK and FKL : https://drive.google.com/open?id=0B4draOa__qd7ZXVPWktZX3FqbTQ VERDICT?!- #$&! :mad:
 
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#4 ·
I wouldn't keep driving it until you I'd the culprit and put a timing belt on the car. Typically timing belts don't show signs of wear with misfire, they just break and on an interference engine like ours total the valve train, pistons, and combustion Chambers in extreme cases.

My personal plan of attack is find a shop to do the timing belt, while there have the intake tract from the maf to the block tested for vacuum or boost leaks, I would also have compression and leak down tests performed.

If everything comes back positive you know it's a sensor, fueling, or coils.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
#5 ·
G.O.A.T. !

That's some great points you have there. I've been so caught up with everything else that I been completely disregarding the belt issue.

Thanks for putting some perspective and clarity to my frustrations. I wasn't thinking clearly and overlooking the obvious.

I'll get the timing belt changed and do the EVAP/BOOST/VACUUM Leak test just to clear everything up.

Did you happen to take a look at my logs and notice anything else crazy?
 
#6 ·
I am not an expert at data logs. I would not feel comfortable giving you advice off of what I read there. I understand enough to know what the numbers mean, but not enough to feel comfortable providing advice about it.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
#11 ·
Your timing belt is an issue. But it is not causing any of these problems I wouldn't think.

Your car is pulling global timing, that means knock is a serious issue continuing with a damn less than 1 is bad news.

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#12 ·
Mmm... I already anticipated this being a bigger issue than just a belt and Boost Leak...

I'm guessing it may be a catastrophic failure of some sort... Ringland... Head Gasket... Cracked Piston... etc. etc. etc.....

RIP RIP!!! Well..... It was a good year....
 
#13 ·
Just curious: Have you owned this car since new?



Compression / Leakdown tests
Boost leak test

See if there's a mechanical issue you need to address.
 
#16 ·
The numbers I read in your data logs lead me to a few observations. Unless something is wonky on my reader your throttle position never reaches 100, you have low boost pressure, and global timing pull.

This is all indicative of a continuous serious knock.

Sent from my SAMSUNG-SM-G935A using Tapatalk
 
#17 ·
There's either a high point in your timing map around 1.1g/rev and 3200rpm, or the knock sensor is picking up exhaust noise at this point, which is what happened to my car.

Use the "adjustments" on your AP to pull a couple degrees of timing from the map globally, and take a driving around log. If your still getting knock events at the same points, its a faulty reading, if the knock goes away, get a pro tune
 
#25 · (Edited)
cruandco said:
Cool, then, I'll give that a try and upload another Datalog as soon I pull it.

I suppose you're right, at this point she is pretty old.

Thanks for helping me get to the bottom of this.

I'm going to make the adjustments and make another post in a couple hours.
Get the mechanical stuff checked out. Continuing to datalog could cause irreversible damage.

Verify there isn't a mechanical issue before doing ANYTHING with the calibration. If you absolutely have to drive the vehicle, do so in vacuum. If you can afford to flat-bed it to a shop, do so; roadside assistance on your insurance policy or AAA could also cover it. I've seen where people had a bad fuel pump fuse, so their car wouldn't start (a regular jump didn't fix the problem), and they needed to get towed home after a night out. After some minimal diagnosing in the driveway during daylight the next day, and a $1 fuse later, they were back driving again.
 
#26 ·
I wish that I would have seen your reply before I did what I've done. :whoa:

I could get it towed to a shop and see what I can get done, but I'd have to wait until Saturday. It's my daily, so I need it for work and taking my kid to and from school.

Damn.... Well, it's too late to take it back now, so maybe you have more input after reviewing these following logs.

*THESE ARE TAKEN WITH A -5 TIMING RETARD*
DATALOGS
3rd Gear WOT with -5 Degree Timing Retard : https://drive.google.com/open?id=0B4draOa__qd7NlExejc4dS04Y1U
Accelerating from STOP to WOT in 3rd Gear with -5 Degree Timing Retard : https://drive.google.com/open?id=0B4draOa__qd7REdYaDlNWm50Nzg
 
#30 · (Edited)
cruandco said:
I wish that I would have seen your reply before I did what I've done. :whoa:

I could get it towed to a shop and see what I can get done, but I'd have to wait until Saturday. It's my daily, so I need it for work and taking my kid to and from school.

Damn.... Well, it's too late to take it back now, so maybe you have more input after reviewing these following logs.
All honesty, I'm not even looking at your logs, because it's not worth reviewing based on the information you're posting...

If your car is pulling timing globally via DAM below .875, it means there is a 95% chance it is a mechanical issue, if you're following the map notes, which per your posts, you are. Whether that mechanical issue is a motor problem, leak problem, heatshield rattle, or sensor problem.

A rental car is cheaper than an engine replacement. If your DAM is getting down to limp mode status (~.5), which means that .875, .75, .625 didn't solve the problem, stop driving the car.

Verify the mechanical integrity with the three tests I suggested earlier before any further datalogs. If you're still having issues, then we can look at the knock sensor being the problem, but to keep testing that theory without verifying other underlying issues aren't present is stupid.
 
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