detonation?

[HURTNEM]

If it's the Cats you can lie on the ground will the car us idling and you should hear some of the rattling. Also, have a buddy rev the engine for you and you should hear it more. You can usually hear the sound at the back of your tail pipe too if the cat is blown. It sounds like aluminum foil is rattling around in your pipes when you've blown a cat. I pray it's something that simple!

 

[1wild-horse]

not exactly. a/f may still be wrong too, timing too far advanced. bottom line is if you dont want to hurt the motor, get a dyno tune or get a wide band and tune it yourself. Expensive mistake not to.

 

[1wild-horse]

lets work through this logically. Did you put the pulley on, load the tune and noticed the noise right away? A noise that wasnt there before? If thats the case, it's deto. and you need to tune it. My diablo dealer/ tuner even told me the canned tune is no good.

 

[MoKo_03SVT]

well....i put the pulley on....installed the tune....but didnt notice the noise right away. didnt notice the noise until about a day later (yesterday). the first time i heard it i thought my back tires were slingin rocks up into the fender wells or something....so i decide to see if i could replicate the sound again...and i could/did. but this time i noticed it sounded more like it was coming from the shifter area, and noticed i could pretty much make the noise happen at will, now.
never heard the noise before the pulley swap. and like i have mentioned...its not loud at all and someone that has never rode in the car prob wouldnt even notice it. but you know how it is if its YOUR car...you hear/notice every little noise...new and old.
i just hope im just being paranoid

 

[Nautilusvt]

Put the car on a dyno... if you're not sure what detonation sounds like don't f*ck around because it doesn't take much to hurt these motors if the tune is off.

 

[UFGatorGuy20]

If it were MY car, I would stay out of boost and take it to a tuner. Simple as that. Don't mess around with throwing torco in, etc. Stay out of boost... drive as slow as possible, shift as low as possible. Hell... trailer it there if you have to.

 

[Jimmysidecarr]

Do you hear the rattle/tin can noise when you rev the engine or only when you're WOT? Reason I ask is a blown CAT makes the same noise you desrcibe above. This could also exlain why you feel the noise is coming from your shifter area as your CATS are right under your shifter area. Seems simple, but may be something as simple as that. I've replaced blown CATS twice and they made the sound you decribed.

This is extremely easy to diagnose:
Jack car up cold, put jack stands under the front(both sides) slide under and bang on the cat with a gloved hand, using the soft side of your fist.
If it rattles inside you have bad cats.
Just so you know stock cats are more robust than high flow after market cats and cat failure is less common.

Check your pump for the heat exchanger. Make sure the water in the tank is moving around. That was my problem. If your air intake temp is too high the computer will mess with the timing and cause detonation.

This is also becoming more common as these cars age. It would be semi intermittent since it would need to be hot/warmed up and after a boosted pull. Pull #2 for example. Though the pcm will usually pull a massive amount of timing and you will usually feel the car "lay over" and feel doggy.

Here is what I recommend doing immediately:
This is assuming you have already put fresh 91 or 93 octane gas in and you are not running around on stale stored(over the winter) gas.
Take your Predator and adjust your fuel as rich as it will let you go.(on my Xcal2 it was only 14%)
Then drive the car to reach operating temperature and in a safe place do a hard(WOT) 3rd gear pull. If it still pings immediately let off!!! and do no more wot pulls until problem is resolved.

If it does not ping audibly I would leave it just like that until you can get to a reputable, hopefully local, tuner and have a safe tune installed and CHECKED.

Detonation is a devastating destructive condition that is not always audible.
If you can hear it IT'S BAD!!
One of the reasons a lot of Terminator owners run a normal platinum plug is so they can change them more often with out breaking the bank for Iridiums each time. Once you have your tune rock solid the NGK Iridiums are a great plug!
The reason for changing to fresh plugs usually is not because the are worn out or dirty.

They are a fantastic indicator of combustion conditions and close examination of the porcelain will reveal tiny metallic specs if you have ever detonated.
So if you have made a correction in your tune or made a change some guys will throw a set of normal NGKs(or whatever) in and drive it and pull em out and read them, to see if the detonation is gone.

Correcting detonation will not remove metal specs from previous events. Hence the new plugs.

Does that help??

EDIT: DO NOT PUT RACE GAS IN... Unless it's all gone when you re-tune it can skew results

If the richer fuel adjustment fails retard the timing in addition.
On mine I merely had to add some fuel and I was golden.

..

 

[WhiTriCobra]

^+1 and whatever one else said. Not worth crapping out your engine. With your diablo tuner, i would add some fuel and take out some timing and drive easy to a dyno. Just like others said, a canned tune is a band-aid till you get to the dyno tuner.

 

[MoKo_03SVT]

This is extremely easy to diagnose:
Jack car up cold, put jack stands under the front(both sides) slide under and bang on the cat with a gloved hand, using the soft side of your fist.
If it rattles inside you have bad cats.
Just so you know stock cats are more robust than high flow after market cats and cat failure is less common.


This is also becoming more common as these cars age. It would be semi intermittent since it would need to be hot/warmed up and after a boosted pull. Pull #2 for example. Though the pcm will usually pull a massive amount of timing and you will usually feel the car "lay over" and feel doggy.

Here is what I recommend doing immediately:
This is assuming you have already put fresh 91 or 93 octane gas in and you are not running around on stale stored(over the winter) gas.
Take your Predator and adjust your fuel as rich as it will let you go.(on my Xcal2 it was only 14%)
Then drive the car to reach operating temperature and in a safe place do a hard(WOT) 3rd gear pull. If it still pings immediately let off!!! and do no more wot pulls until problem is resolved.

If it does not ping audibly I would leave it just like that until you can get to a reputable, hopefully local, tuner and have a safe tune installed and CHECKED.

Detonation is a devastating destructive condition that is not always audible.
If you can hear it IT'S BAD!!
One of the reasons a lot of Terminator owners run a normal platinum plug is so they can change them more often with out breaking the bank for Iridiums each time. Once you have your tune rock solid the NGK Iridiums are a great plug!
The reason for changing to fresh plugs usually is not because the are worn out or dirty.

They are a fantastic indicator of combustion conditions and close examination of the porcelain will reveal tiny metallic specs if you have ever detonated.
So if you have made a correction in your tune or made a change some guys will throw a set of normal NGKs(or whatever) in and drive it and pull em out and read them, to see if the detonation is gone.

Correcting detonation will not remove metal specs from previous events. Hence the new plugs.

Does that help??

yes, very helpful! thank you! :rockon:

i plan on doing this as soon as i get home from work in a couple of hours!

 

[Jimmysidecarr]

Do let us know how it goes... we worry about you kids.. LOL! J/K;-)

 

[MoKo_03SVT]

most definately =]

will have an update posted by this evening

:beer:

 

[SpectorV]

I put on my 2.93 put in a full tank of 93, ran my tune (not a can tune) and everything was fine on the dyno, no hint of detonation audible or on the dyno graph/data. I loaded the updated tune (mine was 10.9 a/f so was rich) both tunes were 23 max timing.

Driving later with the new tune I heard it ANY time I would get on it as soon as it went into boost, sounds like marbles bouncing around from the engine. I loaded the tune from the dyno... still did it. I loaded a tune with 2 degrees less timing.. still did it.

I waited (no boost at all just normal driving) on the tank of gas to be used up and filled up fresh (also my IC pump died sometime in this process so replaced that) and no more detonation at all. I am going to dyno it again soon to ensure its good then hopefully I am good to go. The dyno soon will tell and I will check the plugs as well to double check.

So for me it was bad gas it seems.... will a dyno see detonation where it cant be heard?

 

[1wild-horse]

[ will a dyno see detonation where it cant be heard?
/QUOTE] I dont think so but dont know. I want a knock guage like my buddy's GN but we dont have knock sensors:shrug:

 

[MoKo_03SVT]

I put on my 2.93 put in a full tank of 93, ran my tune (not a can tune) and everything was fine on the dyno, no hint of detonation audible or on the dyno graph/data. I loaded the updated tune (mine was 10.9 a/f so was rich) both tunes were 23 max timing.

Driving later with the new tune I heard it ANY time I would get on it as soon as it went into boost, sounds like marbles bouncing around from the engine. I loaded the tune from the dyno... still did it. I loaded a tune with 2 degrees less timing.. still did it.

I waited (no boost at all just normal driving) on the tank of gas to be used up and filled up fresh (also my IC pump died sometime in this process so replaced that) and no more detonation at all. I am going to dyno it again soon to ensure its good then hopefully I am good to go. The dyno soon will tell and I will check the plugs as well to double check.

So for me it was bad gas it seems.... will a dyno see detonation where it cant be heard?

when this happened to you, could you tell for sure the sound was coming from the engine? like...it didnt sound like the sound was in the car, or near the shifter area, did it?

 

[Romans8:28]

Have you pulled you plugs and examined them?

That's a simple method to diagnose detonation.

 

[Jimmysidecarr]

Have you pulled you plugs and examined them?

That's a simple method to diagnose detonation.

Truth!

 

[MoKo_03SVT]

alright....so here is the update...

i know for sure its not my cats. i did some engine reving with my head out the door (while the car was stopped obviously) and didnt hear anything from the cats.

its not the heat exchanger/intercooler because the fluid still bubbles and moves around.

i didnt have time to change around my tune and go make WOT pulls yet, but will be doing that this weekend, for sure.

last but not least....i MIGHT have found what the problem is. found out my plugs are stocker motorcraft 22's. definately need to change my plugs, but....do you think thats what the problem might be? wrong kind of plugs?

i did a little research and found on another cobra website (modular fords), and found a thread where it said there are 3 different kinds of stocker plugs, and 2 out of 3 them they said "should be okay" with the pulley swap. the 22s which are the ones i have, were listed as 1 of the 2 that should be okay. i dunno...what do you guys think?

 

[MoKo_03SVT]

anyone know if these plugs are okay with a pulley?

 

[1wild-horse]

cooler plug is a must w/ a pulley swap. I also went to copper plug NGK ?br7es? i'd have to confirm that #. Copper will burn a little cooler and take the hot spot off the top of the piston. Rule of thumb has been 2 heat ranges cooler. As i stated and other people too, that canned tune is no good. get her dynoed soon...

 

[DocB]

22s are the midrange stockers and are OK. But since they are out I would put some new ones in there. Copper, V Power, TR6. Can't go wrong with these.