Okay Peeps,
I have an 86 CRX Si and here's my situation: there is a somewhat pinging sound coming from the engine. It is not loud and during idle you can hear it... Its weird cause as im driving it doesnt always ping. Sometimes it will ping louder than other times. So i drove it around and i noticed it pings most when im accelerating...but just like i said it doesnt do it all the time. And im not sure if this has anything to do with it, but when its parked and idleing and if i rev it up and let it go it will want to drop lower than normal idle then pick back up in a second(back to mormal idleing). If you have any suggestions or dianostic test that i can run i can use the advice. Thanks...

 

there are lots of things that can sound like that, and lots of causes for each sound, so without being there, or you knowing what each noise really is, it will be tough to give you a solid answer.

anyhow, to start, stock motor? how many miles? stock timing? what grade of gas are you using?

if you are using regular, go fill it up with super and let us know if it is still making the same noises. pay particular attention to when the motor is really working hard- for instance, while going up a hill or when you floor it in a higher than optimal (meaning that the rpm's are lower than you'd want them to be to make good power) gear.

try that before you get gas, and then after and note any differences between the two grades. If it starts pinging hard during the tests, back off so that you don't destroy your motor and get it home, and we'll go from there.

 

If it's detonation, you probably won't hear it at idle, or if you do, you will hear it all the time. Detonation sounds like a metallic buzzing, can be pretty quiet, it kind of sounds like you have a washer or nut rattling around in the engine bay at high frequency. If you're running a stock motor I doubt that is your problem, mine has 12.5:1 compression and I drove it (very very carefully) on 93 for a couple of days on a stock Z6 map, and didn't get pinging (again, I was driving it super careful, NO hard accelerating).

 

Damnit greg my car is in your avatar!

 

haha. i suppose i should update that.

how about this- when the car is no longer 40% mine i'll get the avatar straight i should have written "all interest to be paid in full by way of fun runs" in the receipt.

OP- while my first post was to rule out detonation (the ping is an improperly timed flame front literally ringing your motor, and sounds like a metallic ping or click), a stock motor with stock timing is pretty unlikely to have detonation issues, as tom is pointing out. as far as anything RATTLING at the engine speeds you are describing i'd put 5 bucks on the catalytic converter heat shield (the one attached to the cat, not to the tunnel).





Modified by rsca_crx at 11:14 AM 8/30/2006

 

i had a 92 cutlass supreme and what started out as a ticking sound in the engine turned into a tin can bouncing in the engine sound.. then a few short days later the engine siezed up. you might want to check for something in the valvetrain that might have broke.. in any case, if something did break, you could be looking at a new head and valve train.. but no one will know until you tear the head apart.. and if you have the time, nothing wrong with checking the pistons and rings to make sure they are good. how many miles does this thing have on it anyways? if its getting high like 2k or so, might as well think about a swap. or replacing said engine with one of like kind..

 

cant pinging come from the valve barely tapping the piston. give that timing a chekc asap

 

ALRIGHT GUYS.....THANKS FOR YOUR HELP. I HAD MY BUDDY COME OUT AND CHECK IT OUT...MY TIMING WAS OFF JUST A LITTLE BIT BUT ENOUGH TO CAUSE THE PINGING!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IIDIEIV619 &raquo;</TD></TR><TR><TD CLASS="quote">ALRIGHT GUYS.....THANKS FOR YOUR HELP. I HAD MY BUDDY COME OUT AND CHECK IT OUT...MY TIMING WAS OFF JUST A LITTLE BIT BUT ENOUGH TO CAUSE THE PINGING!</TD></TR></TABLE>

glad it got worked out without any real trouble