Nxf0

I don''t think this is related catalytic converter. I don't know I could be wrong.
but I hit a jackpot with my car , I also have the catalytic converters noise.
here is the link : but even for a faulty cats dealer won't do anything. I was told that warranty will not cover anything because there is no code / check engine light , and my car used to be in north east and has some rust under. I was quoted $3500 to replace the cats and exhaust.

mjunod

If you look at the thread "Infiniti Consumer Affairs - poor experience" around page 15,16 I posted what caused the pinging noise I had on my 2008 G37S, which was related to a gasket causing low oil pressure to adjust the timing. It was originally diagnosed broken exhaust heat shield and then stones caught in same heat shield but eventually different dealer found the issue which seemed to be occurring on a number of G37's. My repair was covered under extended warranty, but I posted what parts they replaced. Problem never returned and now am at 156K miles.

Weilun Sun

thank you so much for your post
so the dealer check your oil pressure then replace the gasket?
did u have any engine code or any oil light flash or something?
i suspect my oil indicator and header because recently i use WD40 spray my shield bolt and inside and also adjust my oil indicator (there's a little curve) it's also reduce the noise happen
maybe after trying these i'll replace my gasket

carzak

So, it sounds like the noise people are experiencing is actually rod-knock due to low oil pressure caused by a failing gasket. Amazing. I'm not sure anyone realizes the significance of this. If your car is making this noise, there is metal-on-metal contact, which means engine damage, and you are in need of a $2-3000 repair. I mean, that's what it sound like here.

This was critical information. I know to stay away from any of these cars unless they've had the gasket changed, or preferably if they're 2012 and up when the gasket was revised. I can't believe a modern luxury car is experiencing rod-knock because of a bad gasket, and a paper gasket of all things....

Eugenius

Here is something from nissan's forum where people are sharing similar experience with VQ35. Looks like couple of guys were able to fix it by cleaning carbon buildup.
VQ Engine Ping / Knock - Nissanhelp.com Forums

antirice

iTrader: (2)

Ever since I changed my power steering fluid last week, I haven't noticed this noise. Just reporting my observation here.

Eddie Ex

I'm at 130,000 now and I'm running into a spark knock issue. The sound is like a loud knock coming from the engine out of the blue when the car is warmed up and around 1500rpms it'll come loud as ****! And then go away??? From a cold stop. But if I mash the gas harder it won't do it. The dealer said it was because I was using sunoco 93 they have crappy gas and to use shell or Exxon bp mobile one because we dont have Chevron or Texaco in Philly. I did 5 fill ups of Exxon and though the car runs much better but the sound came back. So when I got my car back from the dealer the I couldn't duplicate the sound again after I switched the gas. Now the sound came back.

Eugenius

It can not be "metal-on-metal contact" as you driving it will be always oil film between cylinder wall and piston.
I bough an engine oil pressure kit from harbor freight, and will do the test within a month. I have the same sound more than year and half.

Eddie Ex

The dealer said its spark knock which is due to using bad quality gas like sunoco and luk oil and wawa gas... since I started using Exxon the noise is not as much but still makes the noise less frequently. The oil pressure loss would trip a code wouldn't it? Because I have no oil or engine lights on it

Eugenius

The knock might be due to carbon deposits on piston heads, spark plugs, injectors, valves and etc. I also get worst knock after fill up at Costco Gas Station.
But there is another theory, and you can read some post above, that the knocking is due to failing or already failed gallery gasket. The simple test to exclude or confirm would be the oil pressure test.

Sergio Ortegon

slartibartfast

iTrader: (7)

That's vòila. Pronounced "walláh" in English.

Oil is not the issue unless your crankcase is almost empty and you have rod knock. Oil selection only makes a difference regarding VVEL noise. As for pinging, as long as you're running mid-grade or premium, you will not experience detonation under the conditions you described. Look at exhaust heat shields, or sway bar end links, or brake dust shields.

Sergio Ortegon

Eddie Ex

heat shields and dust shields where the first thing we check and its definately not that...

Eugenius

Ok, here some results.
Yesterday I was trying to test the oil pressure, but the oil pressure port for AWD version is located in a very tight place.
So I had to use several adapters, and as the result it did not seal properly and oil was leaking little during the test. I spent 4 hours trying to make it work. Darn...
So the results are inconclusive, because I did not have fully sealed lines.
At 92C ECT temperature from my generic OBD (should be 80C Engine temperature based on video from Motorvate's) I GOT 11psi idle, 40 psi at 2000rpm

BUT, I do not have any noise almost a month, as I was using Techron Complete Fuel system cleaning every 1500 miles for last 6 months and using only Exxon gas.