Engine knock on stock tune?

[jas11151990]

So I was logging my car and initially found the car was pulling a max of 3.8…..tried a tank of Sunoco 93 instead of the 7/11 gas and logged and had a peak of 4.25. Im bone stock power wise other than GT500 axle back. Anyone have any input? I cannot hear any exhaust rattling either.

 

[charba951]

Is it a negative number or positive?

 

[fulanititoo8198]

Post up a log

 

[jas11151990]

Positive, what's the easiest way to post a log?

 

[by9468840]

pulling 3-4* timing with stock tune? have your car properly tuned by VMP, AED etc. before we get another cylinder #8 post here.

 

[Funny5.0]

pulling 3-4* timing with stock tune? have your car properly tuned by VMP, AED etc. before we get another cylinder #8 post here.

Ive never heard of any reports of a stock or tuned 13-14 N/A melting a #8. The knock sensors should keep his motor in check (as long as they are left on), that is what they're there for.

Not saying Knock is ever a good thing, but some knock with the stock tune is normal. Ive seen +1.0 in mine on a short datalog session just driving around. +3-4 does sound high, OP must have some majorly garbage gas in his area!

 

[jas11151990]

pulling 3-4* timing with stock tune? have your car properly tuned by VMP, AED etc. before we get another cylinder #8 post here.

My car is STOCK, I have been logging with Shaun and this is what we discovered. I will try another station but using Sunoco should have helped when I relogged. I just want to figure this out before going and voiding my warranty if there is an issue.

 

[denali33]

JAS did you load his tunes yet, if so your ecu is already fingerprinted lol. Use a different gas station, I am using Chevron. I had the same issue with VPOWER

 

[jas11151990]

I haven't loaded any tunes just logging my car. I used 7/11 and Sheetz 93 gas when it hit 3.8 and Sunoco 93 when it peaked 4. I will try one more time after I hear back from Shaun.

 

[helli217]

My car was a little lean on the right bank stock, but after my AED tune is pulling 27 degrees max and the computer is adding timing almost all the way through the revs. AFR's are perfect.

4 degrees pulled stock seems a little high but only in my experience, which has been with my car.

You could try an octane boost (Torco, Lucas) to see if that causes the car to pull less timing. That might indicate poor fuel quality/low octane.

 

[YouGoGlenCocoa]

I had the same issue with my stock tune... Potential #8 failure. Had a compression test that showed everything was good. Shaun tuned it and everything is great. Now no chance of #8 failure.

 

[jas11151990]

Well I am glad that the computer is picking it up and keeping everything safe so that their is not a failure. I would like to figure out the cause though.

 

[GearsNBeers]

If you have been driving around on junk fuel your car has adapted to being protective of itself. When you bought a new tank of good fuel did you datalog right away or did you drive it for awhile?

 

[5.0jake]

I had the same issue with my stock tune... Potential #8 failure. Had a compression test that showed everything was good. Shaun tuned it and everything is great. Now no chance of #8 failure.

From my understanding, #8's were mainly caused by tunes with the knock sensors disabled. If not we'd be seeing tons of FRPP tuned cars melting #8's as that tune knock's like a mofo for the majority.

 

[YouGoGlenCocoa]

Shaun @ aed explained on a thread before about a possible lean condition at WOT with the # 8. It showed up when i logged for him getting ready for my tune while i still had my factory ford tune

 

[GearsNBeers]

I think I remember that. Certain coded ecu's had a wacky parameter in them under certain conditions commanded a protect the cats situation that was nasty for people's motors that had off-road pipes.

 

[cb900f]

Add some Torco and see if it goes away. If it doesn't go away, then it's picking up knock from something else.

 

[yngrshr]

From my understanding, #8's were mainly caused by tunes with the knock sensors disabled. If not we'd be seeing tons of FRPP tuned cars melting #8's as that tune knock's like a mofo for the majority.

Who the **** would disable a knock sensor?

 

[jas11151990]

Data logged later on that day after filling up. I'll try to stick with a good station and see if it improves before I go to carlilse. If not I'll try some 100+ and rule out fuel as an issue if so.

 

[scotmach]

Who the **** would disable a knock sensor?

Bama.