I don't know if anyone has experienced this before, but after the car has been sitting for a while I get this rattling noise when i accelerate in the lower rpm range. it almost sounds like if I spun a rod baring but not as bad. as soon as the car warms up the car though the noise does go away. i dunno!?!

I have heard this on my car a couple of times.

The problem is caused by carbon deposits in the engine - you gotta push the car hard to prevent this! There is an Infiniti TSB out on it.

Start by letting the car warm up fully to normal operating temperature and rev the car in neutral to high rpm's for a few minutes to burn off the deposits.

If the problem persists, the first thing to do is use a bottle of BG44K in the fuel tank. Best way is to let the car get low on gas, empty the 11oz can into the fuel tank (you need a long neck or flexible tube funnel!), fill the car up (at least 13 to 15 qallons - I used to recommend half-tank, but that may be too little) with gas.

Then, drive it - hard - till it gets near empty again before refilling. A long drive is a good way to keep a continuous clean going - but definitely do not dilute it till near the end of the tank.

You can repeat with another can of BG44K, but it is best to wait at least 3000 miles before the third (or more) use.

If the above BG44K tries do not work, a full injector rail flush (not just another can of BG44k - the dealer will simply use the Nissan equivalent of BG44K if all you ask is for an "engine flush" - so ask for a pressured rail flush!) may help.

This should take care of this issue - for a while. So, I'd recommend a can of BG44K, ideally for the tank full just before every oil change, for improved performance on this issue.

BTW, I always let my car warm up idling for about 1 to 2 minutes (till the indicator pin has moved off cold a bit) and then start driving. Helps eliminate the pinging a lot!

Z

SZ to the rescue again!

i tried BG-KK about 2 months ago, but i'll try it again.

you think dealer would cover a rail flush under warranty if i told them about the pinging?

i do let it warm up, but even after it's warmed up it'll do it until i take it into the higher rpm range. but it now all makes sense after what you just said.

Teknic73 wrote:SZ to the rescue again!

Always glad to help if I can!

Teknic73 wrote:i tried BG-KK about 2 months ago, but i'll try it again.

you think dealer would cover a rail flush under warranty if i told them about the pinging?

No harm is asking for it! You may have to push them a bit ... talk to Infiniti Corporate to get some help, if needed. I have a very good working relationship with the local Infiniti dealer (I darn well better, having bought three cars from them over the past 15 years and they always do the servicing on my cars!), so I can generally get them to do anything that I insist on - without having to call Corporate.

Z