Pinging and P0330 (1 Viewer)

[racethepilot]

My 97 lx450 has been having a slight knocking (pinging) issue all summer.

The pinging only happens under medium acceleration AFTER the engine has been running for a few minutes after startup. Sure enough, after a few minutes, P0330 pops up, the timing retards, and the pinging does not go away.

I only run 91 octane.

I’ve been through 4 OEM knock sensors so that’s not the issue.

I’ve deleted the EGR system.

I’ve also retarded the timing to the factory 3 degrees of advance.

Spark plugs look great.

Throttle body is cleaned.

MAF sensor looks brand new.

Looking for guidance on what to troubleshoot next. Any help would be greatly appreciated.

 

[mudgudgeon]

You should not need to run anything but standard pump gas in a standard engine.

Get under the hood/ under the car with a sthethascope or long bar and listen to the engine block and head while someone gently revs the engine for you.

If you're hearing a knock concentrated in the bottom of the block you've probably got work rod or crank bearings.

Have an oil sample analysis done. If it shows bearing metal in the oil, this also points to a rod knock, not pinging

 

[racethepilot]

You should not need to run anything but standard pump gas in a standard engine.

Get under the hood/ under the car with a sthethascope or long bar and listen to the engine block and head while someone gently revs the engine for you.

If you're hearing a knock concentrated in the bottom of the block you've probably got work rod or crank bearings.

Have an oil sample analysis done. If it shows bearing metal in the oil, this also points to a rod knock, not pinging

You should not need to run anything but standard pump gas in a standard engine.

Get under the hood/ under the car with a sthethascope or long bar and listen to the engine block and head while someone gently revs the engine for you.

If you're hearing a knock concentrated in the bottom of the block you've probably got work rod or crank bearings.

Have an oil sample analysis done. If it shows bearing metal in the oil, this also points to a rod knock, not pinging

Haven’t put a stethoscope to it but have had an oil analysis done and came back clean. I should say, most of the engine was rebuild about 40k miles ago.

I’ve tried replicating the noise like you’ve described but without load the engine actually revs fine. No issues or noises at all.

 

[mudgudgeon]

Haven’t put a stethoscope to it but have had an oil analysis done and came back clean. I should say, most of the engine was rebuild about 40k miles ago.

I’ve tried replicating the noise like you’ve described but without load the engine actually revs fine. No issues or noises at all.

That sounds promising.

Exhaust leak? At manifold/ head?

 

[racethepilot]

That sounds promising.

Exhaust leak? At manifold/ head?

Honestly haven’t tested it. Had an exhaust shop fix an exhaust leak by the #2 o2 sensor but I’m not sure they tested anything around the head. Let me see and give an update.

Would that be causing that p0330 (knock sensor) code to be thrown though? I guess an exhaust leak could send a wrong reading to the o2 sensors and mess with the fuel mixture.

 

[mudgudgeon]

Yeah, doesn't really explain the knock sensor code.

An exhaust leak at a single port on the manifold can sound like a ping though, and may only be audible at higher revs or in acceleration

 

[ppc]

I’ve been through 4 OEM knock sensors so that’s not the issue.

I would start looking for a problem with the wiring harness. The knock sensors use a shielded wire that caused a similar problem with my 87 Supra

 

[LongDuck]

The knock sensor may also be working just fine, and as a microphone, it's picking up whatever your ear is also hearing. My bet would be to pursue the pinging sound and get to the bottom of that and THEN see if you're still getting a P0330 for knock sensor.

Have you done anything on the exhaust side of the engine lately? Any maintenance performed recently?

I once had to take a car back to the stealership for a knocking noise and showed them the rubber mallet they lost in the bay that ended up between the engine mount and the frame rail. That was worth a laugh (*Infiniti!).

 

[landtank]

Check your timing and you wasn’t to run stock plugs. Iridium’s can cause this.

 

[racethepilot]

I would start looking for a problem with the wiring harness. The knock sensors use a shielded wire that caused a similar problem with my 87 Supra

Just checked the wiring leading to the sensor and the shielding has actually been peeled off and a new connector has been spliced in about 3 in from the plug. Could something this simple cause the p0330 code? Never thought about that.

 

[racethepilot]

The knock sensor may also be working just fine, and as a microphone, it's picking up whatever your ear is also hearing. My bet would be to pursue the pinging sound and get to the bottom of that and THEN see if you're still getting a P0330 for knock sensor.

Have you done anything on the exhaust side of the engine lately? Any maintenance performed recently?

I once had to take a car back to the stealership for a knocking noise and showed them the rubber mallet they lost in the bay that ended up between the engine mount and the frame rail. That was worth a laugh (*Infiniti!).

Nothing done recently on the exhaust side close to the engine. I think it’s crazy how hard it is to find a good mechanic nowadays. Past 2 times I took the truck to Toyota they didn’t tighten my oil cap and told me that they “don’t have the tools to grease knuckles or drive shafts”.

 

[racethepilot]

Check your timing and you wasn’t to run stock plugs. Iridium’s can cause this.

You’re saying to double check that I’m running OEM spark plugs?

 

[landtank]

You’re saying to double check that I’m running OEM spark plugs?

Make sure you are running the proper plugs and check your timing.

 

[racethepilot]

Wanted to write an update for anyone following this thread. My issue ended up being a simple exhaust leak where the exhaust manifold meets the exhaust. Nuts had backed off just enough to create the noise.

No issue with the valves. No issue with spark plugs or timing. Something super simple, just hard to see.