Why do I Still Have Ping?! It came back...

[Wolfie_85]

Alright, it warmed up outside, and I haven't been using addatives in my fuel. When it was still cooler out, it pinged a little, but nothing like now. It's not constant, but accelerating between 2 and 3k RPM, it's there. I'm thinking temp related. No overheating, though.

Steps I've taken so far:
New MAF (wiring looked ok, have new connector just in case).
Pulled octane shortening bar (STILL pinging)
The head gasket has been replaced recently (this SHOULD rule out intake manifold gasket and carbon buildup).

Temp sensor? The one that goes to the PCM, could that be it? Dunno where to go next. EGR? Vacuum seems ok. Gonna pull codes tomorrow, even though it's not throwing a CEL. Could a belt tensioner mimic the sound of ping?

 

[Anime]

Have the rocker arms ever been replaced?

The stock rocker arms were made of softer metal than they should have been, so they get indentations where they contact the valves. The pushrods also wear where they contact the lifters due to poor oiling.

This kind of wear will give valve clatter that is light at first and similar to engine ping, but will eventually be loud, full blown valve clatter at 2-3K RPM under load.

That and lifters that are slowly getting "stuck" in the lower position can cause noise they worse they get.



Poor quality fuel can also cause ping, both from clogging up the fuel injectors and having poor combustion. Sometimes fuel injector cleaner helps but the long term solution is using Top Tier brand name detergent fuel. Stuff like Chrevron, Shell, etc. that has plenty of cleaning agents to keep injectors, valves, etc. clean is the way to go, even if it costs a few cents more per gallon than cheap gas.

 

[Wolfie_85]

I might have to look into the rockers. But this is so intermittant. Sometimes barely there, other times unignorable. It seems to worsen in warmer weather. Around here, we have BP as a brand name for gas, and little else.

Fuel injectors were a thought. Would a bad oxygen sensor do it? I'm just picking things off a list at this point.

 

[Anime]

The clatter from worn rockers is still intermittent - they can be serverely worn down and still quiet when driving around but clatter super loud under load, say when hitting the gas accelerating up a hill or when the cruise control surges to maintain speed on the highway.

Keep in mind that outdoor temps affect things like the oil viscosity, so an engine that is quiet in cold weather can get noisier in warmer weather. Of course once the engine is at operating temp, the oil should be close to the same viscosity no matter what the outdoor temp is, but it's still a factor, since the outdoor temp affects the cooling system, which regulates the engine operating temp, and the oil cools a lot faster in cold weather since the oil pan and engine block is exposed to the cold air.

Bad or dirty oxygen sensors can cause issues, but you'll usually get a check engine light. Still, if the sensors are original replacing them can often give a slight performance bump, but replacing them with cheap aftermarket stuff can also cause more problems.

You may want to try just using BP gas for the next few weeks/months and see if that affects anything. Also be sure you're using 87 octane and not something like 85, and try to avoid E10 or ethanol fuel if you can. Anything like E15 is bad for an engine not designed for it. Ethanol in general gums up fuel systems and causes issues, so it's a good idea to try and run ethanol-free fuel when you can to flush the ethanol gunk out.
It can take awhile to do, just like cleaning the injectors, fuel system, etc.

 

[Wolfie_85]

Ahh, therein lies the issue. I kinda feel as if the rockers might not be too bad, as when the head gasket popped, zero noise. What tipped me off was the climbing temp gauge. I just have to track down what the issue is.

As for gas, ethanol is hard to avoid here. BP's fuel here has ethanol in 87 and 89. The only one with no ethanol is 91. Which I have used from time to time.

I've never tried any gas like the E10 or 15. I just wish I could track this down. I might do some digging under the hood tomorrow. Check vacuum lines and wires. Something has to stop it.

 

[acschilling]

Something really simple that may be causing a ping when accelerating could be slack in your throttle cable. Put the gas pedal to the floor and see how far the butterfly on the throttle body opens. I pulled the slack out of mine about 4 yrs ago with a single zip tie and it needs it done again. It gives me a pinging knock if the temp outside is pretty warm.

I did think about starting a thread about my valve cover gasket replacement and how it cured my cold thru warm-up knock that would eventually go away. I checked for play in each rocker arm while I was in there and nothing jiggled or tapped but the old gasket would flop over on it self at the edges. Replaced with the hard rubber Fel-pro and the knock nearly disappeared. It does it briefly now but it still has older oil it it. Ran 5w-20 this winter.

Check that thottle cable slack! I'm doing mine today

 

[Wolfie_85]

That's something I never thought of. I'll check that too. Thanks!

 

[Anime]

If you've got a climbing temp gauge and the engine still runs hot/warm you should probably change the thermostat. The engine running hot can causing pinging. Did you change the thermostat when you replaced the head/intake gaskets or no? Did you use good coolant and a 50/50 coolant/water mix?


E10 is ethanol, the standard 10% variety. You don't need to use 91 even if it's ethanol-free, but if you ever find a station with ethanol-free 87 that'd be good to try.

 

[Wolfie_85]

Yeah, it got a new thermostat. And I did find a place with ethanol free 87. The temp stays in the normal range now, but I meant when the head gasket went, the hint I got was a climbing temp gauge. Clue two low coolant, I had a bad feeling and checked the oil. After that I said some bad words.