I have a 94 Integra GSR with about 230K miles. In the last month or so I get what sounds like valve ping when I take my foot off the accelerator. Originally it didn't make this noise when accelerating, but it does now a little bit. I checked the valves, which needed some adjustment, but it didn't make any difference. I made sure the oil was not low. I've searched this site and the Internet and haven't found anything. Anyone know what can cause this problem? Timing, vacuum leak, etc.? I'm wondering if it's an initial sign of the engine wearing out.

 

As an unseated/bent valve would have the same effect as lowering the valve stem. It could sound like a loose rocker.
Easy way to check is to put a straight edge across all the valve stems(Yes,without the rockers) and look for the short one.

 

maybe cylinders has lots of carbon. maybe a bad knock sensor.

 

Thanks to those who provided suggestions. Here's a follow up. Last Friday my car wouldn't start. It would turn over but wasn't firing. I thought it was the timing belt, which was within a few 1000 miles of needing replacement. But the timing belt was okay. The ignition coil was bad. The secondary resistance was less than 10K. I replaced the coil and timing belt. I also replaced the distibutor cap and rotor. The rotor was way over due for replacement because I couldn't get the damn screw out. But since the car was dead I didn't care if I trashed the rotor to get it off. After I did all that, the car started and the valve ping I mentioned in my original post went away. So it seems the pinging was due to a failing coil or possibly the excessive wear on the rotor. By the way I got an Autozone Duralast coil. I was concerned because the spec for the primary resistance of the Duralast coil is 1.0, whereas the OEM spec is between .6 and .8 (I think). But it seems to work okay.

 

I've seen the coil read out of spec, and still work. Mine was reading way high, but still worked.

You could have been getting the pinging from a misfire or a weak spark, or bad gas, or a combination of both

 

Glad everything's looking peachy :goodjob:

The primary reistance always seems to read differently from oem spec. in my experience. At least when it comes to Civics and Integras, it's apparently normal for the primary to read as much as double the spec resistance.

It's the secondary that's important, where if it's out of spec you have a problem (and normally the coil no longer works at all if the secondary resistance is over spec).