fsp31

Do these conditions sound similar? Is "pinging" a precursor to detonation? I'm picking up some valve noise under boost at about 3500+ revs, but I don't know whether it's "pinging" or simply valves in need of adjustment. Any advice? Thanks!

edit: I know what noisy valves in need of adjustment sound like, but I don't know what pinging or "knock" sounds like. Right now, what I'm hearing sound exactly like valves in need of adjustment...


[Modified by fsp31, 3:50 PM 12/18/2002]

JT

Why not simply adjust the valves and see if you still have the noise? If the noise persists, then you can concentrate on getting rid of the ping issue, or other possible source of the noise. process and elimination...

fsp31

That's my plan, but I was hoping for an indication either way in order to reduce my stress level until I get a chance to adjust the valves. I have a good bit of driving to do before I'll have the opportunity to spend an hour or two on the car.

mos

Pop the hood and back off t he timing a bit. That might help if it is indeed pinging. Only takes a few minutes with a 12mm wrench. Lots faster than doing the valve adjustment.

rjardy

what do you have to manage your timing?

try pulling out some timing and see if its still there, easier than a valve job.


Rob

fsp31

>>try pulling out some timing and see if its still there<<

Thanks! I'll give it a try. I'm pretty sure the timing needs to be retarded a bit anyway, but I never would have connected the valve noise with ignition timing...

b16ahybrid

Also pull your plugs to see if your runing lean or not...
Is it constant or does it go away after a second or two?

D16A6Turbo

Pinging sounds like crackling or small BB's randomly bouncing around underneath your hood. Depending how bad it is, it can be very obvious or just slightly audible. If your valves are out of adjustment, you can hear the constant tick,tick, ticking at idle...you don't hear pinging at idle...I'm not too sure you can hear out of adjusted valves at higher RPM's...

Pinging is caused by:
1. Too much timing
2. Too low of an octane rating
3. Too hot of a plug
4. A lean a/f mixture

fsp31

I'm sure the plugs have something to do with it. They have the tell-tale signs of being too hot. I ordered some NGK's the other day that are 2 steps colder than what I have now (stupid small town auto shops don't have squat). It may be a fuel problem too since I'm running the DSM 450's on a stock fuel pump. There's probably a drop in fuel rail pressure when those injectors really get going, although my A/F meter (crappy narrow band sensor) isn't complaining.

The gas is Exxon 93 octane so I'm thinking that's ok for 7 psi. I also retarded the timing a bit. The pinging is still there but very faint and only at full boost. Guess I'll wait for the plugs, then get a Walbro 255 if they don't do the trick.

Thanks again for the advice and ideas!

D16A6Turbo

don't stop there...keep retarding the timing...til it goes away...

b16ahybrid

93 octane is good ...all i can get is 92 octane...I run 7psi on 92 with timing retarded to 12 degrees....no pinging...try going a little further because on 93 octane you should be able to run a little more timing then me,

BTW what engine is this? what turbo is it?


[Modified by b16ahybrid, 9:53 AM 12/29/2002]

BigD+Itsuki

I believe I am experiencing the same problem. At 4,500+rpms I hear a quite loud ticking. From what I have heard of pinging its usually pretty quiet this ticking I can almost hear with radio on. Right now im running a D16z6 with a greddy kit complete with blue box at 5psi, colder plugs and slightly retarded timing maybe around 14. Ive been drivng the car with this combo for around 6 months. During the summer with 90+ degree temps and a large Trust type 31 intercooler I believe I never heard this noise. I have never run my car less than 93 octain. Now im experiencing this ticking at freezing temperatures. I don't know when the vavles have been adjusted last but I have put 40,000+ miles on the car and 125,000 on the car all around. Any other advice other than retard timing and looking at plugs?
Thanks

P.S. I do not hear this ticking at idle...

b16ahybrid

Depending on how bad the detonation is you will definatly hear it....it sounds like bb's in a pop can being shaken up....
Could be the colder more dense air leaning out your air fuel mixture.Who knows anything is possible..

fsp31

>>BTW what engine is this? what turbo is it?<<

It's a 98 hatch with a D16Y8 and a internally waste-gated T25 from a 2nd gen Eclipse. The car is specifically for autox. That's why I selected a small turbo. The way it's been performing, I'm more than satisfied with what a T25 can deliver. I get full boost before 3000 rpm's, and it's still pulling hard at 6500. I don't know why people are having problems with these turbos giving up at 5000 rpms. Maybe they're having some weird waste gate issues...

Ok, I'll go ahead and keep moving the timing back. Just didn't wanna get to crazy with it since I won't get to a timing light this week.

I've also heard ping called "dieseling" because it sounds a little bit like the noises a diesel motor makes. It's a fairly faint sound. You have to listen for it when you're boosting or going fast.

Thanks again y'all!

b16ahybrid

Dieseling is when you turn the engine off (and remove the key) and it trys to keep runing.It continues to fire and turn over a few times...

With that set-up you shouldn't be detonating, Pull your plugs to see if your runing lean.If you are having detonation it's either to much timing or to little fuel.I'm runing 7psi on a b16a with 10.2:1 compression and 92 octane with no detonation so you should be fine...