My wife's 2002 Automatic P5 has 59,000 miles on it ad has just started pinging on acceleration (not all of the time though). She runs 87 and has tried different bands but on some days it does it often. Sometimes fuel booster doesn't help. She is too cheap to buy premium or 89. Her car just has a CAI and extended reach plugs (thinking about a colder heat range though). I know what causes detonation, but is this a common problem on extrended mileage P5s? I thought they had a more sensitive knock sensor than this.

I don't think it is the loose VTCS screw problem people have been having, as it is just intermittent (A plug inspecion [upcoming] would tell). Fingers crossed...

 

fwiw, my wifes mustang (99 V6) had horrible detonation problems that we could never correct. Ended up selling it and buying a 3S, now it's detonating!!

Octane test is KEY. she'll need to either fill up with 91-93 to see if it stops OR she can have at least 6 gallons of 87 in the tank and add a gallon of 100% Xylene to the tank to see if that fixes it. That would give her 7 gallons of 91 octane for about $5-10 as opposed to filling up with 91 octane. IF the octane increase fixes the problem pull the plugs and inspect for burning or white heat marks. Now would be a good time to add a can of "BG's 44K" to your gas tank to help clean the foul system. After checking/replacing the plugs, adding the bg's your next step would be cleaning/replacing of your EGR valve (if it's faulty).

check it out and let me know what you find.

 

I've added Regane and redline injector cleaner. Has been long though. Where do I get the BG stuff?

 

it's kinda hard to find. I've only found it at dealers. My local honda dealer has it for about $12/can...it's real good stuff but a little pricey. I also use this to vaporize into my intake to clean out the carbon build-up around the valves and TB....

If you can't find any in your area let me know and I'll ship you out a can.

 

I have read that the NGK long reach plugs can cause detonation, so when I swapped mine I started using 89 octane immediately and have no problems. I have since added an MP3 ECU but stuck with the 89 and still no problems...

 

oh yeah i forgot about his plugs....

 

yeah, go back to the regular plugs. shouldnt be necessary to run high octane gas

 

That was my original thought. It started as the weather got warmer. Might try a colder extended reach first.


Roddimus, I think I'll try the Ford Injector/Fuel cleaner. I used to use it years ago, but haven't for a while. It is a little more expensive, but is concentrated as hell. (Same thing they use when the pressure clean the injectors)

 

yeah, so is the BG's 44K I was talking about. I use an IV drip to vaporize it into the engine and it works wonders. Use what you're comfortable with man. I was just making a suggestion.

 

Why do you use extended reach plugs?

 

That's cool. I just think I will try the Ford stuff because I can get it locally. Nothing against your suggestion.

 

They REALLY DO smooth the idle and help the pull at the top of the rev range.

I' believe that a 1 step colder heat range in this plug will prevent the pingging. If not, I'll put them in my car next plug change (already running extended reach with the MP3 computer and 93 octane).

I just wish my wife wasn't so cheap with the gas (she only has to drive 1 mile to work )

 

I use the "extended reach" plugs and have had them for a full year down here in Houston where the humidity is over 100% and the temperatures and reach over 100degrees aswell and have had no problems with detonation. I use 87 octane gas on every tank. Of course my car only has approx. 13k miles on it so might not be the best comparison to a high milage car.

 

Yea, carbon build up etc. makes a big difference.

 

Drove it around saturday (in the rain) with 89 in it an heard no pinging. Of course it was hard to hear with the rain and my wife blasting Pantera