Rep Power: 0

Have 2003 Civic Si hatch and for a few weeks it's been making a tapping noise in the engine compartment. My husband says "valve job uh oh" but my mechanic says "nah, sounds like an injector, they make noise after you get a few miles on the car" (car has 160K). Taps at idle and taps faster with acceleration. Drives me nuts so I keep the radio loud but don't want to ignore a serious issue. Was also told by two mechanics that this model does NOT need timing belt changed as it has a timing chain to last the life of the car. True or false?

 
Rep Power: 367

uhn...

not an introduction, rather an issue...

moving to right forum sections...

 
Rep Power: 519

Use a stethoscope to pinpoint the source of the noise?

 
Rep Power: 119

If you can hear a Honda injector without a stethoscope or similar device then you have a serious issue.

As too the timing chain, it has a tensioner and as that chain wears out it gets longer and the tensioner stops being able to hold it and you will start getting noises and if left to progress, damage up to catastrophic.

Yes those chains can last 2-300k miles, but neglect proper oil change intervals and I seen them worn out under 100k and chattering.

 
Rep Power: 224

I had an '03 Si at one point, it made it 150k miles before the timing chain tensioner gave out. The engine jumped time and ended up bending 8 valves. Definitely replace it if it hasn't been done.

I also had an '07 Accord with a 4 cylinder (similar K series engine), it went 280k miles before the chain stretched so much it was eating through the chain cover and the tensioner couldn't keep it tight.

 
Rep Power: 229

Why not unplug each injector at a time and see if the sound goes away?

You'll have to clear the CEL codes after for a misfire.