Rep Power: 0

I have a 2004 Honda Civic EX 5-speed MT, 54k on it. I've noticed that, for some reason, the idle just doesn't sound right. The engine does not surge or lose revs, but I swear I hear it misfiring. If you listen to the tailpipe, you can hear it. Rather than a drumroll sort of sound, every so often it sounds like a cylinder has a bad detonation. The plugs (NGKa) have less than 5k on it. My mom had an old 86 civic that made the same sound but much more noticeable and my old man (mechanic) said it was prob. burnt valves. Just wondering if I could have the same problem.

Notes: The car isn't throwing any codes at all. Still get about 32 mpg with mostly city driving. No smoking from the tailpipe. Use middle grade gas. But here's the important part: the first owner (I'm the second) drove the car with a bad O2 sensor for quite some time. I've heard that doing that could burn the valves.

Any thoughts or suggestions you guys might have would be appreciated. I just wanna know so I can fix it before it gets serious. Is it expensive to change the valves?

Again, thanks!

 
Rep Power: 188

You would have to get a vacum test and a compressoin test done to really figure it out.The exhaust Valve is usually the most common to "burn".

If you do it yourself it might not be to expensive but it is a lot of work. Do you plan on doing the test, and or repairs yourself?

 
Rep Power: 285

+1 it's inexpensive, but a lot of work of very technical work. The head needs to be completely removed and disassembled.

 
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thanks guys, and yes, I plan on doing it myself with my dads help of course if it does turn out to be a valve issue.

Couple more questions:

1) if it had a burnt valve, wouldn't the car be showing a code for some sort of misfire?

2) could the sound just be poor valve adjustment. I don't think the car has ever had its valves adjusted or checked.

Again, I really appreciate it guys.

 
Rep Power: 285

1. Codes aren't 100% reliable.
2. Possibly, post a video of the sound.

 
Rep Power: 254

Ill have to agree without a video its hard to tell. However a bad O2 sensor wont burn a valve, it might however destroy the catalytic converter maybe thats the funny noise you hear. I am just going out on a whim here.

 
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Here's the vid! Hope it's clear enough. Audio sucks. I'll try put up a better video later but I just wanted to get something up here to see what you guys think. Idk, maybe it's a clogged/bad injector or a bad coil pack. Maybe it's just me...haha!

[autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=1116& transactionid=1322947807-501133695&posted_by=em2maxamillian_www.civicforums .com&youtube_video_id=8NmQZYL3oo8[/autostream]

 
Rep Power: 235

Let's see a vid of the engine bay while running just to confirm but, I think you just need a valve lash adjustment. Don't wait till 100K miles like recommended by Honda. Usually you need to do it every 40-60K miles.

EDIT: Yeah, I can definitely hear the valves in the background.

 
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Sorry it took so longer, but here's an under the hood clip. It prob. needs adjustment. What do you guys think?

http://www.youtube.com/watch?v=ZdYnj...el_video_title

 
Rep Power: 235

Yep. The rapid clicking is the valve chatter.

 
Rep Power: 254

Nothing to lose sleep over they dont sound that bad. Adjust them when you can.

 
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Thanks guys, I'm gonna get them adjusted next week. It's my daily driver, so ya, I wanna get it done soon because I can hear the valves tapping a but when I accelerate. Is this a common issue with Hondas? I've had a couple friends who have had Hondas most of the life and I remember them getting their valves adjusted quite often.