Undertow74

iTrader: (45)

ummm interesting without hearing the vehicle.......but let me ask you this, you say it is at higher RPM's......do you have Cats on your car....because if so, the platinim honeycomb inside might have broken apart, and at those higher RPM's is rattling around inside the housing......i say this from experience i had a friends ride that was rattling and thats exactly what it was, just a thought let us know!

jdhedman

iTrader: (31)

I am no help. Just wanted to say that you have one sick ride and I hope you get it figured out

Rybar

iTrader: (11)

Thanks for the replies. few different things apply vs a 4th gen F-body. The exhaust is full custom stainless with no cats.

I also had it taken to an exhaust shop to re-check and tighten the entire exhaust.

We also pulled half the dash, heater controls and gauges apart, still nothing.

LS6427

iTrader: (2)

Don't know how a TB can cause this issue.....but anythings possible.

Well, this can all be checked at once by removing the heads. At least you have nice room under that hood to work compared to the new F-Bods.

Bent stuff will cause it.

The blown head gasket can certainly cause detonation but you would see a loss of coolant and possibly white smoke out the tailpipes. Probably overheating and boiling over of the coolant too.
*****Coolant system pressure test might be a good idea to do first....if you lose pressure and have no external leaks....you might have found the problem......Coolant is leaking into a cylinder(s)........
NOTE.....if this happens, DO NOT start the engine afterwards. You need to remove all 8 spark plugs and see which cylinder has the coolant in it. Or take all 8 out first, then do the pressure test. If you start it and there is coolant in a cylinder you could hydralock it..and heavily damage the engine.

Simple scan will tell all with the 02's.

????

Rybar

iTrader: (11)

Thanks for the reply, I will do a coolant system pressure test and scan the computer for codes.

The power steering pump idea I found by doing some google/youtube searches.

BTW the motor's compression is about 11.5:1 and I run 94 octane pump gas. Plugs are new. I've tried octane booster with no luck. The power of the motor feels 100%, there is no rough running or power loss that I can notice.

Rybar

iTrader: (11)

Hey guys, finally did a scan with HP Tuners. Can somebody check the file and tell me if they see any problems??

Only went WOT for a small burst once since the clutch and trans are brand new. I noticed the knock retard when the car was colder, but once warmed up it didn't retard. I also shut the car off once, and it died at a stoplight a second time.

I guess the main thing I want to know is if it's detonating.

Let me know what you see, if anything.

Ryan

Rybar

iTrader: (11)

Here's a couple vids, the noise is hard to hear.

http://www.youtube.com/watch?v=QI3E41FWN6c

http://www.youtube.com/watch?v=xBXcqGDRaq8

Rybar

iTrader: (11)

and a second scan file

Rybar

iTrader: (11)

I now see the most KR I had was about 3.9

The noise seems to be something mechanical rather than detonation.

These screenshots of the KR may help:

djjonesivs

iTrader: (2)

do you have a wideband?

did you tune this your self?

those are crazy high fuel trims.

Rybar

iTrader: (11)

Well I should have updated this, the issue ended up being a mechanical one. My shifter was tapping the side of the tranny tunnel hole. Not sure how this just started happening but the shop that was doing some work on my car found the problem.

As for the above questions, car was dyno tuned by a friend who does tuning. We used an Innovate LM1 handheld wideband kit.

BETEP

How did they fixed it? I think I have the same problem just started. Noise coming right from shifter hole.
Thanks

Rybar

iTrader: (11)

Sorry, problem is back. I'm having another shop investigate it soon. It drives me bonkers.