Please help!!!
I had my car dyno tuned a couple months ago with some large bore heads on my stock displacement LS6. The head and cam combo wasn't very impressive so I decided to change head and cams.

I went with AFR 205's milled .0020 and Patrick G Torque cam. After install the car rans absolutely amazing. I took it back to the same place to have it dyno tuned again. Picked up 30rwhp and 30rwtq!!!

Here is the story.
On the first pull of dyno tuning there was some detonation. According to the guys who tuned my car, there was room for a lot of timing advance because of the large bore heads. The compression ratio was greatly increased with the new heads causing the detonation. Didn't think much of it.........these guys are professionals!!! He punched in some thing on his lap top and dyno'ed it again and sent me on my way.

The car was night and day different after the tune. Throttle response was lazy, didn't feel like a 500HP machine........anymore!

About 150 miles later, check engine light comes on. Car now makes some nasty "clanking" sound at idle-2000 rpm. I take the car to autozone to see why the check engine light is on. It turns out right and left knock sensors are the problem.

Called the place that tuned it and they said it could be an "internal engine malfunction".

WTF??? Any ideas on what could be going on with this thing?? I need some expert advise. I am affraid to drive this thing after I invested over $4K. I have not raced or ragged this thing out. This is a weekend car.

Thank you!!

 

TTT for Lunch.........

Need help!

 

What code did it throw. Its possible the knock sensors or knock sensor wiring are malfunctioning

 

I am on my friends computer and I forgot my password.

According to Autozone it is the knock sensors. What would be causing this?? Should I be concerned and most importantly..........how do I fix it??

Like I said above, there is some rattle in the engine at idle-2000rpm.

What do you think??

Thanks!!

 

Something internally maybe bad. It could be anything. Get the noise checked out. Your knock sensors are going way out of range to compensate for the mechanical knock. The knock sensors are thinking its detenation so the PCM is pulling alot of timing. If it knocks it will pull timing way to far and say your knock sensors are bad. Its not the sensors its something inside. Maybe a collapsed lifter but it could be worse. Could even be the tune being way lean. Take it back, it could have done something bad if they advanced timing too much.
-Alex

 

I plan on taking it back to have them look at it. From what they told me, they backed the timing out a bunch because of the gain in compression. The car ran awsome when I drove it up to get tuned. On the way home from getting tuned it didn't run like crap but didn't run even close to as good as it did up there.

Thanks Alex.

 

Do you know what the tuner changed? sounds like they took a good tune and made it bad.

 

They just said they took out some timing. I wish I knew more, I could call them but you can never get in contact with anyone.

The guy ran it on the dyno, it detonated pretty bad. After that, he went and got his lap top, punched in a couple things, dyno'ed it, and sent me on my way. That was it.

I sent you couple PM's today Patrick. Thanks for your imput.

 

Their are multiple codes related to the knock sensors, I would check and see what specific codes it has stored and go from their. It could be the sensors not working and timing pulled back or the sensors detecting too much knock, etc

 

Could it be you are missing on a cylinder.. You would def get a SES light, and knock sensor codes.
Something stupid......plug wire fell of... check all the wires, make sure they are nice and tight.

I wouldnt run the car. It could be something worse....but look at the simple stuff first.