Rep Power: 0

Hi,

I have a '98 DX with the D16Y7 that I believe is suffering from spark knock. I don't have a tach, but if I were to hazard a guess, I would say it is most noticeable above 4,000 RPMs in second and third gear. I know it's not a transmission issue, because the noise (like chains dragging) is still present even in neutral.

Are there any common issues that this could be from? The car has 155k on it and I only purchased it this Summer. I don't know what the previous owner used it for, but it is really solid all the way around.

I usually fill up at Getgo, and I've heard some less-than-favorable things about the quality of their gas. Next time I need to fill up, I'm going to head to another station and even up my Octane level. I'll probably add some carbon-cleaning fuel additive as well.

Are the EGRs known for being restricted/stuck? Could mine be so without throwing a CEL? A new one is around $300 dollars so I would rather not spend that much. If it persists after my next fill up I'll try cleaning it before replacing it.

Could this be caused from anything else? Could the timing belt have jumped a tooth and not caused any catastrophic damage?

 
Rep Power: 518

Have you ever HEARD spark knock?
Would you know what spark knock was if it snuck up behind you and screamed BOO?
(Why does spell check not like the word "snuck"?)


Does the engine have some rattle noises and you have no idea what they are?
Or is the noise not even in the engine at all....



I can't think of any that I would describe as "chains dragging" unless it is rotten heat shields on the exhaust.


I would tell you to post a video or recording of the noise, but I already know what to expect from a crappy recording over the intarwebz. Try it anyway.

I expect main bearing rattle from those engines anywhere over 100k miles. Not a big deal as long as they don't suddenly get worse.
But a pro may need to decide what your noise is.

Maybe you need a pro to have a first-hand listen at it.
Maybe you figured out why someone got rid of the car.



Timing belt can jump a couple teeth without severe damage, but most people would notice a big problem with the way it runs. If it jumped toward the advanced position, that really could cause spark knock. But they normally jump to a retarded position, not advanced. Def worth checking though. I would check ignition timing to see......if ignition timing is correct, then cam timing must also be correct. (Someone would almost have to destroy the distributor hold-downs to move it far enough to hide a cam timing problem.)
I would not be popping the top cover and physically checking cam timing unless the ignition timing is wrong, like 20-40 degrees wrong.

 
Rep Power: 0

I've never heard it personally, no.

To me, it sounds like popcorn except metallic. I really can't describe the sound because I've never heard it before. Everywhere I read seems to say the same thing... upon lugging or higher RPMs, it will make a 'chains behind the car dragging' noise. Mine only does it at higher RPMs, but I don't lug the engine.

The best I can describe the sound best is in the frequency of popcorn in the microwave, but it sounds like little metal beads or marbles coming from the driver's side of the engine compartment. I can really hear it in second and third gear.

Tomorrow when I get home I'll put it up and see if any of the heat shields seem loose. I'll also try to record it and post it, but, like you said, I don't know how well anyone will be able to hear it.

I'll get that done and report back, but if I drive 100 miles (about until my tank is empty) I'm going to up the Octane and put some fuel additive in just to see.

 
Rep Power: 518

None of these are spark knock:


www.youtube.com/watch?v=0FEeBwm9qCs

www.youtube.com/watch?v=JIOdS7XbHys

www.youtube.com/watch?v=J9KFJzSozno

These are "death rattles".

 
Rep Power: 0

Minus the turbo noise, this is almost exactly what I hear. That popcorn sound beginning at 3 seconds.

[autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=1325& transactionid=1350274500-671656187&posted_by=98_CivicDX_www.civicforums.com &youtube_video_id=Due7mkTHMlw[/autostream]

Is that spark knock?

 
Rep Power: 518

I'm listening on a crappy laptop.

I can only assume it is, that is why it is titled that way.

If you seriously think you have it, I'd check timing first.
Use a proper shop manual for instructions though.


HTH