Detonation on Stock Motor?

[Fox 5.0]

I created a thread in the Road Kill section about racing an E46 M3 recently. What I didn't mention is at the top of 3rd and 4th, I was hearing pinging, as in detonation. My car is completely stock, like down to stock mufflers and intake tube. I just rolled over 86k miles today. As far as the PO's notes in the maintenance booklet go, she's still rocking the original spark plugs. Could this be the problem? Maybe (from wikipedia) unburned fuel/air mixture beyond the boundary of the flame front is subjected to a combination of heat and pressure for a certain duration (beyond the delay period of the fuel used), detonation may occur. I'm not well versed in detonation but i've rarely heard of a stock engine having issues with it. I always use 91 octane Chevron gas. Any ideas?

 

[bumsoil]

was it a clunk, rattle, did it sound like bottles, or was it something else?

I would guess cats going bad. when they start making noise they can sound like all sorts of things from rod knock to detonation.

 

[Fox 5.0]

Of your examples, I guess it sounded like a rattle/bottles clanging together but very quietly. I've heard pinging before and it definitely had that sound to it. Think the cats could be going bad with only 86k miles??

 

[Prototype007]

Just to make sure I understand you correctly, you're running 17 year old spark plugs and wondering why the vehicle has a miss in the gears that presents higher load on the motor?

 

[me32]

Dude you need a full tune up. Spark plugs/wires, pcv, fuel filter, air filter, clean the maf.

 

[Fox 5.0]

Just to make sure I understand you correctly, you're running 17 year old spark plugs and wondering why the vehicle has a miss in the gears that presents higher load on the motor?

LOL, basically, yes. Although I can't guarantee they are the stock spark plugs, the PO just never wrote in the maintenance schedule that he replaced them. Will put them on the list of things to do.

Dude you need a full tune up. Spark plugs/wires, pcv, fuel filter, air filter, clean the maf.

I've done the PCV, fuel filter, its got a K&N drop in and i've cleaned the MAF. Spark plugs it is. However, do i really need to do the wires as well?

 

[Fox 5.0]

Spark plugs on order.

 

[arayray]

Does it sound like this?

My car sounds like this ever since I installed a BAMA tune on it. Still can't figure it out :fm:

 

[Fox 5.0]

No definitely not like that. Only happens at WOT near redline and definitely the 'ping' sound. I'll see if the spark plugs help and report back.

 

[laddanator]

Does it sound like this?

My car sounds like this ever since I installed a BAMA tune on it. Still can't figure it out :fm:

Sounds like a valve guide

 

[me32]

LOL, basically, yes. Although I can't guarantee they are the stock spark plugs, the PO just never wrote in the maintenance schedule that he replaced them. Will put them on the list of things to do.



I've done the PCV, fuel filter, its got a K&N drop in and i've cleaned the MAF. Spark plugs it is. However, do i really need to do the wires as well?

Yes it needs wires too you have 86k on the car. Over time heat/cold wear the inside of the wires. It causes resistance in the wires an doesnt give the full spark it use have. Take sometime to read on why tune ups are important an what needs to be done for a full tune up.