Pinging? Valve tap?

[EVOL_TURBO]

I am experiencing some sort of pinging or valve tap. Its been doing this from the day I bought the car a year and a half ago. I bought the car bone stock and have put 30k miles on it with no problems. The motor currently has 150k miles on it but it was supposedly rebuilt at around 90k.

THE NOISE ONLY HAPPENS WHEN THERE IS NO LOAD ON THE ENGINE. When sitting still and when first letting off the gas when moving.

It does not ping/tap at all at idle. Nor does it ping/tap under load or boost.

 

[Talonman86096]

Are you using 93 octane? I know ive heard before if you just use 89 or even 91 thats sometimes it will ping or tap. You should only run 93 in turbo applications. Also could be the lifters. You could try adding some lucas with your next oil change and see if that helps it at all.

 

[EVOL_TURBO]

Well, I live in Cali so I can only get 91. I think I'll try some octane booster and see if that helps at all. I think its kind of loud to be the lifters. Thanks for your input

 

[aacordon]

lifters are actually really loud, had to replace mine with 3rd gen. try some sea foam as well

 

[IceMinion]

Hey guys, I'm having something similiar to this.

-Metallic pinging at idle from cylinder #1
-very loud.
-Trips the knock sensor.
-Seems to go away somewhat when I rev the engine. too loud to tell for sure.
-Noise goes away completely when I unplug the plug wire

4g64 weisco/eagle 8.8:1 built by QPR
Compression numbers are all around 220 -/+20 on my craptastic tester.

checked for cylinder contamination, didnt see any bolts/nuts/shavings/midgets in the compression chamber.

I have also replaced the injector.

My guesses are lifters or maybe a blown exhaust gasket.

 

[jayson427]

over time cheap octane booster can gum up your injectors and such. if you want 93 your better off getting some sort of race fuel and mixing it with 91.

 

[sciondan]

Can you get an audio clip? Are you sure your not mistaking pinging for piston slap?

 

[jayson427]

If it was piston slap he would hear it more during boost.

 

[KewlWinter]

Sounds like lifter tap. You probably have the original valve lash adjusters with the 1mm hole. There are a couple of things you can do to stop this annoyance.
1. Make sure your oil is clean and you are using the lowest weight for your climate and driving conditions. Thinner clean oil has a better chance of making it through the lifters.
2. Make sure you dont have some cheapy oil filter installed that doesnt have the anti-drain valve. This valve keeps the oil from draining away from the engine after shutdown so that it is present at startup. If you do the $14.95 quick oil changes, chances are you need to replace it with an OEM type oil filter.
3. Clean the valve lash adjusters.
or
4. Replace the valve lash adjusters with the improved version with the 3mm hole.

I had this annoying tapping and doing options 1 and 2 solved my problem.

I realized after I replied, that you did have a rebuild. It is possible that if enough material has been milled from the cylinder head or engine deck that the above options may not be enough to totally make the noise go away. You might have to perform the 2g head oil mod to restore proper oil flow to the head.

 

[IceMinion]

KewlWinter, Thanks for your reply. I'm really lost on the whole oil pressure flow issue, the engine is together and running, what should I do. I have no way of knowing if the oil porting was done during the engine build, QPR Performance doesn't exist anymore.