I'm having pinging/knocking issue right now. I took my car to the infiniti dealership for an oil change and coolant flush at 69900 miles and a random check on the valve cover (removed coil pack #3 and no oil drip). After that I started to notice knocking and pinging, and then after 70000 miles it start to ping and knock like crazy. This happened under load when driving. If I give it gas, I will hear loose metal chain type noise, then after that it I will hear a distince pinging sound. I had brought it to the nissan dealership for a fuel flush and 2 degree timing adjustment. The pinging and knocking is less, but is still there.

I always used 93 octane. Before I brought it to the dealership, I tried Shell Nitrogen gas (93 octane also). I wonder if that had anything to do it. I'm on a different brand of gas right now (first tank since pinging started) and I'm still hearing knocking. I have only used up 1 or 2 gallons maybe.

I hate it because this happened when my power train warranty over. I driving 05 6MT by the way. I have read up on the other pinging thread started "Bythabay", but there was no solution.

Is it a bad batch of gas? Should I change the spark plugs now?

 

The manual clearly states using other fuel then specified will effect your car. Not sure if the nitrogen fuel is to blame. Could be a bad tech that messed with your timing. And when you drove the car, it fuked something up.

 

This may be a silly question, but did you check your oil level? Oil starvation will cause a really awful pinging/chain grinding noise from your engine. Granted you got your oil changed 100 miles ago, but service technicians goof too. If it is indeed oil starvation, most likely the engine could be severely damaged.

 

Yes I checked the oil level and it was full. I have been driving the truck now to avoid any further damage and try to find a fix. I'm hoping it was a bad tank of gas.

 

^ Possible bad gas if been in stations storage tank loong time = degraded oct rating. Is kinda weird right after dealer visit pinging started though.

Have them run A/F 'alpha' numbers under load with their consult. Normal range on bank one and two is 95%-105%. If below or above those, something not right and causing your issue. I'll guess a O2 sensor might be going but not enough to throw a MIL. Have them check mv's on your O2's to see if in acceptable output range as well.

G/L

 

I also own a Max that I use as my DD. Anytime I use anything less than 93, it's pings like the dickens. Never mind ever going up a hill. Not trying to start a discussion here but, our engines are highly optimized when it comes to performance, straight from the factory. Seems like even one bad tank of gas will make this engines ping. I suggest you empty it asap and fill it up with a fresh tank of Shell 93, or Exxon.

 

I don't understand why is it that the manual says that the sedan can use 87 octane and the coupe can't. I understand the 6mt has 298hp but the AT coupe and sedan are identical specs so what is the difference?

 

try seafoam. I love it.

 

Culi,

I've got the same problem. Did you ever find out what the issue was? Did you ever get the issue resolved?

 

The actual brand will make little difference since it is tightly regulated and in many if not most cases actually comes from the same spigot. What probably is more important is to purchase from a high volumn dealer.

The cars also learn so if running on something higher in octane than required and switching to something less it has to relearn.

They should however under low loads handle most changes without issue.

 

Unfortunately E10 may show a decent octane ON AVERAGE but be grossly inferior on the Motor Octane Test due to blending chacteristics with base fuel.

If a splash blend of 10-20% racing fuel stops the problem, you better find a better quality refinery.

May be cabon fluffed intake valve stems from previous bad gasoline?

 

the 5AT sedans have a different TUNE obviously...thats why 87 octane can be used and why their power is rated lower. Its also why after tuning sedans make coupes cry.