Signs of Detonation

[mspeedpro]

I think it would be nice to start an 'official' thread on all of the simple tell-tale signs yal know of that indicate detonation... I know I have heard of examining spark plugs-- what do you look for? etc. I know a shop can check easily-- what do they look for?? Sorry if some feel this is beating a dead horse but I dont know if a thread has been devoted to it. Lets help me and all the other n00bs here be safe(r) at boost.

Stephen

[AutoBox]

oil everywhere and a nice hole in ur block....oh and the nice paper weight rob that put the hole in ur block :)

[Matthew]

the noise, and i hear you will see smoke.

i cant hear the noise with an open dump though.

[igdrasil]

Detonation...

well...you want signs BEFORE breaking the engine?
Detonation will most likely break pistons this way:

http://www.msprotege.com/members/igdrasil/setup/brokenpiston.jpg

1. Examine the plugs for greenlike or yellowlike colors
2. Examine the plugs for piston debrees (running too hot)
3. Or if the plug is too white.

If you see smoke, then your pistons/headgasket or piston rings are damaged.

Check compression if you can...this will tell if your cylinder is leaking.

My last motor had suffered severe detonation by running lean and advanced timming. 3 pistons were like that. It was smoking bad, but if you vent the PCV valve, the smoking will be gone, some oil may bath the engine a bit and some smoke, but thats all.

Another trick you may do to find out if you have broken pistons is this:

Put the finger to close the hole on the side of the valve cover (obviously remove any hose attached to it). And do the same with the PCV hole in the top of the valve cover...wait 30secs - 1 min. Take out the finger or anything you used to close the PCV hole, it if explodes compressed gasses, you have compression problems.

[KyRaceFan]

your plugs will be "speckled" with white dots....

[mspeedpro]

i dont know if this is related or not but i have found oil on my engine before-- it is on the valve cover and *appers* to be leaking from around the edges of the mazdaspeed logo.... leaking isnt the right word because it is very subtle and small in quantity-- its been been there since stock boost btw--- thnx

[DiscreetSpeed]

if your runnin 93 octane or an excess of 15^psi then i wouldnt worry about it.
being that the car is turbo'd there could be oil in oddest places.
signs of it on the plugs would be beaded insulator...black speckles on it as well.
the electrode could be damage, maybe even bent(deformed). plz do not say listen for it cause if you can hear detonation on our cars id love to shake your hand. our engines are noisey as hell and it almost impossible to the naked ear.
something that could cause it as well is the engines temperature. too hot= possible detonation on 93.
but i have yet to see any runnin 93 octane and boosting 15-17psi.

oh and if you insulator is straight white it doesnt mean that its detonating..may detonate because the system is runnin lean..the problem there would be fuel delivery and not detonation.

[DiscreetSpeed]

i dont know if this is related or not but i have found oil on my engine before-- it is on the valve cover and *appers* to be leaking from around the edges of the mazdaspeed logo.... leaking isnt the right word because it is very subtle and small in quantity-- its been been there since stock boost btw--- thnxthis is odd because the engine cover sits above the valve cover...weird that you have this if this is what you have..take your engine cover off(4 10mm nuts) and check your valve cover gasket.

[AutoBox]

My Cover Has A Oil Residue Also...its Just Residue Form The Heat Blanket On The Hood I Think..i Check Edmy Valve Cover Ans Its Not Leakin

[Rich24km]

if your runnin 93 octane or an excess of 15^psi then i wouldnt worry about it.

plz do not say listen for it cause if you can hear detonation on our cars id love to shake your hand. our engines are noisey as hell and it almost impossible to the naked ear.
something that could cause it as well is the engines temperature. too hot= possible detonation on 93.
but i have yet to see any runnin 93 octane and boosting 15-17psi.

Same here but 14 psi (cool) . If you're really worried, goto a dyno and go through your gears under whatever boost you set and have them listen with an engine stethescope that'll help you feel a little better about it.

Discreet, your car looks like mine(hump)