# 3.5 Altima PINGS



## vq35 (Sep 5, 2005)

My 2002 3.5 Altima pings at part throttle around 1700 rpm. I've used only 91 since I purchased the car new. It has always done this since I purchased it new, I notice it more now that I've been driving more conservatively.

Any known soloutions for this would be appreciated.


----------



## Asleep (Jan 19, 2003)

vq35 said:


> My 2002 3.5 Altima pings at part throttle around 1700 rpm. I've used only 91 since I purchased the car new. It has always done this since I purchased it new, I notice it more now that I've been driving more conservatively.
> 
> Any known soloutions for this would be appreciated.


im guessing its out of warranty by now huh? if its not, you need to take it in - detonation can kill an engine.


----------



## vq35 (Sep 5, 2005)

*Some Predetonation is Normal?*



AsleepAltima said:


> im guessing its out of warranty by now huh? if its not, you need to take it in - detonation can kill an engine.



Thanks for the reply, I took my Altima in today (9-30-2005). I told the advisor that my 2002 V6 Altima pings when hot, under part throttle around 1600-1800 rpms.

He says that many customers complain about the pinging in the 3.5 V6s. They have contacted Nissan about the problem in the past and each time, he says, that Nissan considers some predetonation to be normal. He himself has a Nissan Titan, which of course has the V8, which also has some predetonation. He suggests using Mobile, I use mostly Chevron 91. 

I suspect an overlean mixture under these particular conditions. It doesn't ping under cold conditions when the ecu is providing a extra rich mixture. 

Back in the 80's I installed a BAE turbo charger on my 1980 280ZX. Their instructions required me to change the fuel pump and compress the spring on the fuel regulator by squeezing it with two sockets and pair of channel locks until I had the recommend fuel pressure. They also placed a resistor in series with the temperture sensor. The resistor fools the ecu into thinking the engine is cold and squeezing the case of the fuel regulator provides an increase in fuel pressure by increasing the preload of the diahpram spring. This was a shotgun approach to richen the mixture for the turbo. 

The Technosquare ECU for the Altima reduces the compensation reaction of the ECU to the oxygen sensor. There may be some hope here for pinging 3.5s.

http://www.technosquareinc.com/altima.htm


----------

