Car update.

[AJP turbo]

I would not tune the car until all mechanical gremlins are gone...if u disclose that to a tuner up front they most likely won't even touch the car...there are quite a few tuners that require a datalog of the stock tune to verify a sound car before proceeding....this is to protect them from chasing their tail on problems not caused by the tune but when the end user can't confirm either way

[RagingPenguin]

It's apparently a common sound on the F150s under heavy load also. I can't verify but have seen a few posts on the internet about pings being cleared up by tuning.
At this point it's my only course of action. My thoughts are that the exhaust and cold air are to much for a stock setup. Only one way to confirm without replacing everything.

[AJP turbo]

So your contention is that a driveline ping can be cleared up by a tune?......we'll take it easy on your selected tuner when you say it's still shifting funny and clunky and there should be some way to fix it because others have said that a tune can fix it....

Fords stock shifting logic is meant to be smooth and quite and maybe a bit lethargic so if it's making noise now it will continue if u have a mechanical issue..but hey, throw a tune at it and firm up the shifts a bit and run the piss out of it...it'll at least be a good time right?...can't hurt...

[RagingPenguin]

So your contention is that a driveline ping can be cleared up by a tune?......we'll take it easy on your selected tuner when you say it's still shifting funny and clunky and there should be some way to fix it because others have said that a tune can fix it....

Fords stock shifting logic is meant to be smooth and quite and maybe a bit lethargic so if it's making noise now it will continue if u have a mechanical issue..but hey, throw a tune at it and firm up the shifts a bit and run the piss out of it...it'll at least be a good time right?...can't hurt...

Sorry I should have been more clear. They feel it's still some form of spark knock. They've already had my driveline torn apart. They couldn't find anything. I'll still do a full fluid service but so far the driveline feels fine. No odd behavior doing tight turns in parking lots either.
In his eyes if it was experiencing any issues there the hard down shifts should also provide some problems.
The suggestion is higher octane fuel or a tune to try and eliminate the knock. The only other option was to replace the exhaust and intake with factory to see if had any effect but tuning was much more cost effective.
After this they don't even know where to look next. Neither do I.

[FoMoCoSHO]

I feel like tuning your car when it has knock on the stock tune is a horrible idea. This was a dealership that advised you to do that? Why are they not sure it is knocking? They should have a flight recorder available to see if it is indeed knocking....

Have you logged with sct or Torque to see of that is actually what is happening?

What octane fuel are you using?

[AJP turbo]

I highly doubt what u hear or think u hear is spark knock or pinging...the ecu will never let the spark knock get so far as to make itself audible...if it's actually audible spark knock that's really bad...to properly diagnose knock or pinging u need to be datalogging the knock sensor, timing, air fuel and maybe misfire counts....then I'd go from there....this ecu will ride the edge of knock and use the knock sensor to continually adjust timing for optimum performance...stock tune for a Taurus will allow 4 degrees of advance and 5 degrees retard from knock sensor but can go higher or lower based on other compensations....these aren't like the old cars that u can hear pinging from knock....

[RagingPenguin]

Its not a constant sound. I can only replicate it going up seriously steep hills. The kind of hills my F150 would be digging into second gear just to maintain speed.
Even at that its not consistent. On flat ground it doesn't occur anymore.
I agree FoMoCo, its not a great idea but it will offer some insight into the problem, if it clears up then obviously the CAI and exhaust are to blame, if it doesn't... well I don't even know where to look now. I mean now that its got a 6 cylinders the thing seriously scoots now. I was playing with a Skyline R34 on friday coming home. No problems in performance or knock.

I've logged with torque but was getting ridiculous KR readings, apparently due to me using a cheap tool and a cheap program. Fords scan tool couldn't see anything in their testing either. It could just as easily be them just getting me out the door also. 

91 octane. 

[RagingPenguin]

I highly doubt what u hear or think u hear is spark knock or pinging...the ecu will never let the spark knock get so far as to make itself audible...if it's actually audible spark knock that's really bad...to properly diagnose knock or pinging u need to be datalogging the knock sensor, timing, air fuel and maybe misfire counts....then I'd go from there....this ecu will ride the edge of knock and use the knock sensor to continually adjust timing for optimum performance...stock tune for a Taurus will allow 4 degrees of advance and 5 degrees retard from knock sensor but can go higher or lower based on other compensations....these aren't like the old cars that u can hear pinging from knock....

That's what I suspected also but they are insisting its a spark knock. Its very very minimal however. It could possibly be something to do with the torque management?
The only other possibility is the fuel line pressure noises they spoke of are actually a real thing. Car doesn't exhibit any funny behavior at all other than a split second rattle.

I'm at a loss and this is my hail mary pass.

[AJP turbo]

U mean an R35 skyline gtr....r34 is not allowed to be imported nor is the r33 yet

[RagingPenguin]

U mean an R35 skyline gtr....r34 is not allowed to be imported nor is the r33 yet

I'm fairly certain it was a R33 or R34. I'd dare say the R34 as the rear lights look the most similar. I only passed it once before it hit the disappear switch. Both rear lights were different sizes so that elminated the R32 for me. RHD as well.
I could also be wrong though. I wish I had of taken a photo as it was a nice car.

[AJP turbo]

Do u live in canadia? Then maybe...otherwise  only the current gtr and the r32 from 1991 and older can be imported legally to the states...the current r35 is produced for North America so no need to import...all others not in that range can be seized

[RagingPenguin]

Do u live in canadia? Then maybe...otherwise  only the current gtr and the r32 from 1991 and older can be imported legally to the states...the current r35 is produced for North America so no need to import...all others not in that range can be seized

That I do sir.

[AJP turbo]

Ah then u probably know what u saw...I assumed u were from "Merica" ...I forgot how many Canadian folks were here....america is retarded on the importing car laws...we allow all the antique and classic cars to be on the roads with no airbags and 1 side view mirror and people think they are cool cars and they have no cats...but I can't buy a 1995 gtr.....I've tried...they have to have crash certifications that cost a few hundred grand and u need 2 because the first one gets destroyed

[SHOdded]

Back to topic:  You mentioned the occasional split second rattle.  Can you give the occurrences more context, for example, at startup, in those "knock" situations, etc.?  Possibly oil starvation/timing chain if engine related.  If you can, datalog frequently, so the incident can be "caught on tape".  Forgot to mention, check and clear the intercooler while doing the fluid changes also.

[RagingPenguin]

Only under extreme load. High RPM after it shifts at WOT. 1-2 2-3 in my testing. Only on hills can I replicate now.
Cold starts sound like new now