Ok, I'll try this question again. There have to be numerous people with the tech knowledge on this site to help. I have a 2006 mt base model with no mods. When in 6th gear at about 75mph and about 2700 rpm, if I push the throttle to pass a car I hear a rattling noise from the engine. Yes, I always use high octane gas and the oil has been changed on time or early. I can get this noise in any gear if I'm accelerating below 3000 rpm. My dealer has no idea. What do you think this is?

 

i had this very problem with an 05 G35 coupe... dealership was of no help and accused me of running lower octane fuel... i had never put anything less than 93 octane in the engine, so i tried the n00b thing and put in octane booster and chevron techron fuel additive... this did exactly nothing to help the issue... so, i decided to do some research on my own... here's what i found:

the pcv system on the VQ35 motor is notorious for dumping oil into the plenum... at idle, it's under major vacuum...enough to collapse standard fuel hose (this is important and i will explain why later)... so, i decided to take apart my plenum (i was putting on the Motordyne MREV+, anyway) and what did i find? a plenum FULL of oil...and this oil was going down the runners and directly into my engine... this small bit of oil was diminishing my fuel's octane rating and causing the pinging... so, i cleaned my plenum, went to Home Depot and purchased the necessary items to create the home-made catch can...and VOILA! no pinging after the installation of the catch can...

now, granted, someone will debate this post...but, do yourself a favour and try it... make sure you clean the inside of the plenum during the install of the catch can... the following thread should give you the details on what parts to buy and how to create your own catch can... i suggest getting fuel INJECTION hose as it is lined with plastic on the inside and does not collapse at idle...

good luck and post up your results... i'm tired of hearing people say it's bullshiz...

LINK:

https://my350z.com/forum/showthread....ight=catch+can

 

PROVE IT!







...JK

I couldn't resist!


.

 

HA! you know, i WAS going to recommend that the OP pick up the Motordyne MREV2 to keep from having to clean his lower plenum... but, NOT NOW!

 

I finally managed to get rid of my 06's pinging when I traded in my 06 for an 07.

Glad you found a cheaper way to get rid of it

My wife's 06 rev-up barely pings at all even with the MREV2 and spacer

 

neither the MREV2 nor spacer cause pinging... it's the bloody oil causing diminished octane rating...

though, i should get back at tony for his above post and say that it was the MREV's fault!

 

I thought anything that leaned out the mixture more might contribute to pinging. But I don't know much...

I did notice oil in my MREV2 lower collector when I took it off my 06 to put it on my wife's 06.

 

interesting, my 06 pings like crazy. I think Ill buy one, or do the homemade one.

 

Thanks for all this. However, I'm not really qualified to do your fix especially with a car still under warranty. I'll try to take a test drive with the dealer. They just don't seem to be much more knowledgeable than I am.

 

leaning out the A/F can cause pinging... but, the MREV doesn't lean the vehicle out since it's just a lower plenum... the spacer, on the other hand, does allow for leaner conditions, but i've never heard of anyone having pinging after putting it on...

the oil in your plenum was the cause for your pinging... if you had of used the home-made catch can, i'm sure it would have stopped... it's odd how some cars have mad pinging and a lot of oil in the plenum, and others, like your wife's may never have oil in the plenum...

 

the catch can WILL NOT void your factory warranty... you will not be splicing / destroying anything OEM and will retain the one OEM hose removed... all of the parts for the catch can are aftermarket and can be easily removed and replaced with the single OEM hose removed during the process... it takes five minutes to replace the OEM hose if you ever want to do so for warranty work...not that it would be needed...

where are you located?

 

I'm in the Kansas City area. I just spoke with another dealer in town and he's going to take a ride in the car next week.

 

ahh... i was going to extend the offer of installing the catch can for you if you were in the Atlanta area... good luck with the dealership... but, honestly, i doubt they will be able to resolve the issue for you... be sure to mention the pcv system and oil in the plenum theory... they'll scratch their chins and say "naw..."

 

Unfortunately the fuel pump sticker ws placed on the pump by marketing.....plus the average octane can be manipulated by raising the RON number [a RON point costs <1/3 of what a MON point costs at the refinery].

Ethanol is high in RON blending points but lower in MON blending improvements.

http://www.btinternet.com/~madmole/R...RONMONPON.html


By the way these octanes are measured at a maximal rpm of 900 which doesn't correlate well with high performance engine with multiple valves and high compression.

93 may be good enough for most AVERAGE engines until the air temperature rises.............why most ecu decrease ignition advance as the air and coolant heat up or the AC is turned on === all indicators of above normal temperature.

 

summer fuels are always of a lesser octane than winter fuels, as well, due to what you describe... but, my problem occurred during winter months at colder temps... issue was VQ35 pcv system and oil in the plenum...