Ok I did a bit of research on here and figured I would post my results for others to read as well as get input from other members.

So I am getting a heck of allot of spark Knock in the upper RPM range in all gears but most prevalent in 3rd and 4th gear. I think I can just hear it better in those gears.

Possible Causes of Spark Knock From Research

Bad Tune
Bad Gas
Carbon Build up on Pistons / Valves
Excessive heat in cylinder
Restricted Fuel Filter
Funked up Spark Plugs
Oil Being Sucked into intake through PCV

Did I miss any?

I have had the car Tune Checked about 4 months ago... Knock was not as bad then and did not appear on Dyno...
Been through 10-15 Tanks of gas Not that
Did the Decarb procedure 2 times.... No change Still Knocking
Consistently at 190 in DIC Motor seems to have this at all temps ...
Have NOT done a fuel Filter yet.
Replaced the Plugs ... No Change
Have done Nothing with PVC system

So.... I am going to try a fuel filter tomorrow....
If its not that Should I do the catch can install? I do not see how this could be the Sole cause of my spark knock
Any Other Ideas?

 

The other is if its running too lean... from your tune?

 

I will run it back up to the Dyno after i fix all the Knowns

 

IT may be something that is getting worse all the time.... eliminated the carbon so maybe its this fuel filter passing less and less fuel

 

Running lean can be caused by fuel sock clogged, fuel pump failing, fuel pump getting lower voltage on hot or ground side, injectors getting clogged, improper tune. You can have too much ign timing, blown head gasket, incorrect heat range plug, too large combustion chamber, too small head gasket bore in addition to the things you mentioned. You didn't mention your build. Is the engine stock? Tell us everything you have in the engine and everything you have done. Start troubleshooting the knock. Try higher octane fuel. It would really help if you had something like HPtuners to log your knock retard and see how much timing you're running and a wideband to see if you're running lean.

 

My engine is the stock 2002 Z06 In regards to heads and block crank pistions. Heads have not been off the car but I have installed a Cam and a set of Shorty Headers. Also have stock intake with removed lid (Zip tie mod) I am going to do the fuel filter tonight. Will update after that .....

 

 

My ideas...

Possibly an un-metered air leak going into the intake?
Dirty MAF sensor?

 

Might just be the tune after the cam install.

Did even more knock start when the outside air temps started getting cooler? The MAF reads cooler IAT's which translates to "more air" causing a lean condition if VE and MAF are not providing enough fuel. Could be other stuff as well as mentioned above....

Best to have someone with tuning software (and knows how to use it) do a scan while driving around then have a look to see whats causing your KR issue.

My guess...Cooler air making things worse. VE table needs work? MAF table needs work? Spark tables need tweeking? PE table to lean? ect. ect. ect.

 

How would I clean the MAF?

 

a company named CRC makes a goood MAF cleaner. Google it. It runs from 4.99 to 10 bucks. Many of my local auto parts stores carry it. Over oiling your K&N filter will cause a MAF problem.

 

We may be on to something ..... If I had to put it on a time table its possible that the date of my last K&N filter cleaning would come close to an increase in ping.....

 

The problem with cleaning and oiling K&N filters is that when you do your best to fully coat the filter, one can't help but over do it. What I do is wash it, oil it and then lightly wash it again. There is still enough oil residue left to protect. I have seen people's oil dripping off the filter after being oiled and sitting for a few hours. Not good. They wonder why they just cleaned and oiled their filter and the car doesn't run as good as it did with a dirty filter. The oil doesn't allow air to flow very well and becomes quite a restriction. We first discovered this on our 4-wheelers where it was really noticeable. You might just be in for a real treat!

 

I removed the MAF housing. Sprayed an electrical cleaner on it. Then I used a Q-tip with some electrical cleaner on it and VERY CAREFULLY and VERY LIGHTLY wiped the gunk off the two sensor wires.

 

Thanks..... I am going to get some of the CRC stuff tonight and give it a whirl. Guess puttin her in the dishwasher is out of the question lol.

Another queston
MAF ... Mass Air Flow Sensor ? Does it tell the computer total volume of air and what temp the air coming in is at? Does it check density?

MAP Sensor ??? what is this ... Do we have one?

 

MAF - Volume, yes. Temp, no. That would be the job of the Internal Air Temp sensor.

MAP - Mainfold Air Pressure. Measures the barometric pressure inside the intake. Used to calculate te AFR. Yes, we have one.

HTH

 

Also add knock sensor malfunction to the list

 

Ok..

I have cleaned the MAF and still got some Knock...... So guess I will get the ole fuel filter..... Tried it with motor cold (coolant at 100F) and had same knock above 5K RPM till progressively getting worse till I lift at 5.8K


On the knock sensor could it be bad and not throwing any codes? Those are under the intake correct?

 

The air temp (IAT) is measured at the MAF (built in) on the later C-5's.
01 -04's ??? The IAT sensor is located in the drivers side of the middle of air bridge of the earlier C-5's, it's seperate of the MAF.

 

Thanks for the clairification.