4.08 VLSD, NICO 8-way ECU, full exhaust with custom headers,
Tokico Blues with Eibach springs, Stillen FSTB, 20mm RSB, 255 rear rubber.
Of course I forgive you. That is your God's function. Your crime is forgiven.
However, your stupidity requires a response." -Leto Atreides II

Basically there is a rattling sound on randomly, not very noticeable though, during acceleration especially on hills. I have to turn off the AC / music before I could hear it.

Maybe a loose part under the hood? Sound will not come on at neutual/park even at high RPMs...

How should we start troubleshooting?

http://forums.maxima.org/showthread.php?t=484940

"its the timing chain hitting the cover. a lot of us have the problem.

two causes -
low oil (the tensioner need oil pressure to work and keep the chain tight)
tensioner itself is bad"

Thoughts?

1. Oil level and tensioner is good
2. Occurs only when is warm out (70+)
3. Occurs only under load, especially hills

He suggested running BK 44K or has the fuel system professionally cleaned for under $100. What do you all think?

Engine is 40,000 miles... been running on 92/93 Techron since 32,000... Not sure what the previous owner used though.

For $100, what does the "fuel system professionally cleaned" include?

I'm a big fan of BG products. I highly recommend using th BG44K just as a part of your regular preventative maintenance.

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Get your pimp gear here!

Will ask more details about the fuel system cleaning

I just join this forum to seek answer to the same problem with my 2004 I35.
Around 1800-2300rpm, at any speed, I would hear the rattling/pinging/ ticking/ dieseling noise. Basically, the cheap-gas noise. But I have been using only premium since new and have been changing oil (Mobil1 10W-30) every 5-7000 miles. From what I can gather on-line, I used SeaFoam in 1 tankful, then had Pepboys did a fuel system clean for $107. Then I "cleared" the ECU by leaving the neg battery post unconnected overnight. The noise is now reduced to a narrower band, b/w 2000-2100rpm but it is still there.

I also read about SeaFoam through the PCV and cleaning the MAF. But where is the MAF? Is it inside the air induction system? Is it easy to do for a non-mechanic? Will these 2 steps get rid of the problem?

Other posts also mentioned bad O2 sensor? How do I test mine? The
"Check Engine" light does not come on in my I35. Other posts still said that
the noise could be from timing chain hitting the cover. I wonder what is the
percentage of VQ engines have this problem. The Infiniti dealer was no
help. They only want to push for 60k, 90k service and without engine light,
or code, they think it's ok. One guy even tells me that "it's designed that
way!!!" Well, I have a Nissan Quest with 218k miles and it's certainly not
designed that way. So yes, I'm down on Infiniti right now. If I can figure
this out, I'm going to write Inifiniti about it, then trade the thing in for a
Lexus.

Thanks in advance.

Did you notice the noise happens more frequently when it is warm outside? I do on mine. Recently is getting quite cold here in Seattle (low 30s to high 40s) and the noise is almost completly gone.

Others have suggested it is a heat shield rattle sound which I have not checked it out in details.

I'm going to have to wait till this weekend to locate & clean the MAF sensor.

A lot of us have reported the noise occurs more frequently when it is warm out. If it is the MAF, I doubt the variation in air temperature will make so much difference. my .02

Thanks

Rod Erenburg

I wonder if rubbing alchohol would be gentle enough?

That is exactly the same problem have had with my 2004 I35 since it was about a year old. I'm on 75K now, and everytime I go up hills, or keep it under very light power just to keep speed on highways, it sounds like a can of marbles is loose in the car.

So, from what I read here, it seems like the best solution is to get a fuel system cleaning and clean the MAF?

I did see a few mention a fuel filter, but I thought I35s had a built in, non-changeable filter?

would appreciate any help i can get thanks.

Quote, originally posted by bekker109 »

Help! Infiniti i35 in safe mode won't go over 2500RPM/ 60mph lights say "slip" "TCS Off" Check Engine Soon Paid $130 for dealership diagnostic they say Mass Oxygen Sensor cost $750! Anyway to cut this cost. Can it just be cleaned? TKS Bekker

The Mass Air Flow sensor is located in the intake tubing. You can try cleaning it with electrical contact cleaner. Just lightly spray the cleaner on the inside of the sensor and let air dry. If you need a new one a quick search of one of NICO's sponsors came up with $393.04 + shipping.