05WIMustang

Hello board!
New to this website! We have a 2005 Mustang V6 auto, legend lime that we have owned for a year. Awesome car - can't believe we own a Mustang

Couple things/concerns. I have looked on the internet for weeks for some guidance, and would appreciate any assistance possible:

1.) The Mustang seems to have some spark knock, pinging, detonation. I know people (myself) will confuse these words as they can mean slightly different things. The car exhibits the following behavior:
a.) a pinging like noise when accelerating at higher RPM's (4-5k)
b.) a pinging like noise when going up inclines, at steady or increasing RPM's (from 1700 plus)

Those are the only times you can hear it - and its most notable when the windows are up and the radio/fan off.

2.) I also notice that the engine idles very high (like 1500 rpms) when we first start it up in the morning. It doesn't seem to slow down very quickly, and I hate putting it into gear when its that high. I rev it slowly and it does come down. I know the throttle body needs a bit of cleaning since it has "coking" that can plaque electronic throttle bodies.

NOTE: There is NO CEL! Never!

Here is what I have done:
1.) New sparkplugs. Old ones were OK looking other than the gap being larger than it should be (no burnt off tips, abnormal colors, etc.)
2.) Cleaned the MAF sensor using CRC MAF cleaner as prescribed by others (carefully take out, and spray down the wires, let dry, etc)
3.) Chevron Techron (the good stuff - not the cheaper stuff)
4.) Premium gas. I don't remember if it was a full or partial tank - or if it helped.
5.) Resetting the computer by disconnecting the battery after cleaning the MAF

I may have changed the fuel filter, but I don't remember.

Some things I believe might be causing the issue:
1.) Fuel filter if I didn't change.
2.) The car MIGHT be modified - as it had painted calipers in front, and I see the remnants of a NMRA sticker in the front top of the windshield glass (yes I am generalizing, but I am trying to solve a problem)
It might have a tune, and might not have the parts on it now that it had from the previous owner. I've read that some tunes can mean the air/fuel mixture run lean and thus have this issue. I don't know how to tell, other than having the dealership reload the software.

I don't have any smoke, vapor, or burning of oil. No strange noises or bizarre traits that I can observe. No hesitation or misfiring.

Like I said, no CEL's and I cleaned the MAF sensor. Please help!

Nuke

If it's pinging then I'd continue to fill-up with 93 octane (or whatever your highest is) multiple back-to-back-fill-ups. The previous owner may have had an aggressive tune on the car and one fill-up may not adequately bring the tank up to par.

I also prefer SeaFoam over the Techron in these situations. Techron is great stuff and I use it about every 10k miles as a preventive maintenance item but I believe SeaFoam is better for "problem solving".

I really don't think the fuel filter is the culprit but it would be prudent to replace it if you haven't already.

05WIMustang

I let it run almost to E, put Premium 93 grade BP gas in. I also put a bottle of Lucas engine cleaner that I found laying around.

I will buy a can of Seafoam (the spray type) and see what kind of success I have. I see I need to before of the MAF sensor, but that is alot further downstream.

I will report back the results.

kevinmalec

+1 on the Chevron Techron fuel cleaner! Works great and I also get Chevron 93 octane gas!!

If you haven't already, definitely have your fuel filter replaced out.

FYI, It is normal for your car to start up in higher RPM range and then gradually go down.

I would also recommend cleaning the Throttle Body. It is real easy to do. ;-)

Do you have a cold air intake or stock air box? How's the filter?

tx_zstang

Sounds like an aftermarket tune is on the car and expecting 93 octane gas. As suggested, run the fuel tank low (1/4 tank or less), then fill up with 93 octane. Do it a couple times and see if it makes a difference. If it stops pinging, the PCM is probably holding a performance tune.
Someone asked about if you have a CAI? Do you? If so, the car most likely will have an aftermarket performance tune. As such, if using 93 octane makes it stop, you can continue to use 93, or contact a tuner and request a different tune for 87 octane (very good to do for better fuel mileage and lower fuel costs), but it will feel slower when you do that.

I used to have both 93 and 87 octane tunes, and on long road trips, would use 87 octane to save on gas. But when driving around locally, would revert back to using 93 octane and the performance tune for it.
The custom tune for 87 picked up almost 2 mpg better mileage on the highway over the factory stock tune, and 3-5 mpg better than 93 octane tune. Nice little savings on a long trip.

05WIMustang

No cold air intakewhen I bought it. I put in new filters about every 6000 miles and this one is brand new.

I put in a full tank of 93 the other day and will for the next tank as well.

If the tune was used or intended for use with a cold air intake and its not present can that cause problems?

I have a single GT takeoff muffler BTW

05WIMustang

I should add still no cai

Alec

If you have a tune for a CAI but have the stock airbox it will not run right. You'd want to get a correct tune to adjust for the stock airbox

05WIMustang

Ahhh.....an excuse to buy one.....

Does it matter the brand?

Alec

I'd recommend the Bama SCT SF3/X3 tuner. That's what I have on my 05, love it and sell tons of them