Hey all I’m new here so I hope some of you guys can help me out, so I bought a used 2010 G37X 7AT with 97k miles at a sheehy Infiniti dealership in annapolis, and after owning it for a few months I noticed the throttle is laggy and it doesn’t get up and go like it doesn’t have any low end torque, I get beat by corollas and econo boxes all the time after a red light and it’s annoying lol, and a knocking noise after I accelerate from a stop or a complete stop in general, it won’t happen all the time just after a complete stop, I’ve changed spark plugs, cleaned MAF and throttle bodies but it’s still the same, even changed the oil to PP 5w30 with a plb14612 filter but everyone praises redline so I changed it as well 5w30 with the OEM gtr filter, It feels like it has no torque below 3k, but at 3.5k she moves and revs all the way to redline with no issue, it has 103k miles on it now after a year and half of ownership and she hasn’t died on me once so I’m wondering if it’s just some sensor or something major, there is a knocking noise in front of the engine but it’s not loud like rod knock, sounds like tapping when it’s cold or hot, I have post maf tubes, drop in filters and a muffler delete if those mods even matter, hope anyone can help me with this issue.

 

Change diff trans fluid along with plugs and 2 cycles of bg 44k

 

I haven’t changed those except the plugs to OEM denso 3457, I have used at least 5 tank fulls of Lucas octane booster witch stopped the noise for a while but came back but it’s not that noticible as before but the hesitation was still there, I even installed a catch can and new PCV valves too, I haven’t seen any good tutorial on how to change trans fluid on the AT trans, unless I get someone to do it. I’m still not sure about the slight knocking up front on the engine, I heard the same noise on a YouTube video and the owner said it was a belt tensioner, the drive belt was replaced by the dealer where I bought it before I bought it, not sure if it’s the tensioner or a worn pulley.

 

Are you throwing any codes?

 

Nope, no codes at all, I heard it was just the hot temperature so I’ve been plugging my obd2 scanner when it was hot out and never saw any codes pop up, if I remember right in the heat the engine coolant stays around 210 and when it gets cold I see it around 200, but yea never popped a code since I bought it

 

Check your catch can

 

I have, there’s not much there, I don’t drove the car a whole lot, it’s only been 2k miles I had the catch can on, I even replaced both pcv valves to see it helped, it did for a bit then came back noise wise

 

You could be suffering from a mild crack to the gallery gasket, loss of oil pressure at low rpm. At 3k it should be past 45psi which is enough for cam timing and lift to activate and vrooom.

Another possibility is worn chain and guides that create too much flex changing the timing all the time making it run retarted.

If oil additives quiet the noise then you can assume it has to do with the lubrication and you add that to loss of power and you can start assuming it has to do with oil pressures and timing components

You should open your next oil filter to see if you find any metal shavings.
You should also check your oil pressures as infiniti has specs on what they should be, anything lower and it's the gallery gasket. If this is it then prepare your wallet as your chain and guides are probably worn out also.

 

I got a quote from a shop near by me that has done it before and cost $2400 witch ain’t bad, plus I have saved money to pay for some repairs because I heard of the galley gasket issue but I have heard of people with 13 g’s having the same noise when accelerating and having lower miles than mine, but I find it weird that sometimes it feels fine below 3k when the engine revs around 700-800 rpm at a stop light and when accelerating from a stop, will adding a oil filter with higher PSI by pass valve help? Like adding the rx8 oil filter? Prolly stupid to ask but just curious.

 

At this point it's not worth it increasing the oil pressure will more likely result in more leaking of oil pressure, You need to have the car properly diagnosed. These are some of the issues that it could have.

 

Interesting question, but nope.

The bypass valve in the oil filter doesn't have any impact on the system oil pressure. That valve is a safety device and it opens if the oil filter's flow is restricted or plugged and prevents the oil filter from splitting due to over pressure.

System oil pressure is determined by oil viscosity and engine RPM, until the oil pump's internal bypass valve starts to open at about 100 PSI.

If the system oil pressure is low, generally a cam position code will be set. (P0011 / P0021)
To put your mind at rest, you might want to have a shop check the oil pressure.
Here is the process:

 

[QUOTE=GiGGity37;4265894 I get beat by corollas and econo boxes all the time after a red light and it’s annoying lol, and a knocking noise after I accelerate from a stop or a complete stop in general, it won’t happen all the time just after a complete stop, [/QUOTE]
What happens if you are stopped and then floor the throttle?

Our engines don't make a lot of power under 3,000 RPM, and I'm wondering if you are used to a car that has more torque at lower RPM.

It wouldn't hurt to scan for codes, even it the check engine light (CEL) is not on.
The CEL is only turned on if the engine control module (ECM) has determined an increase in emissions.
It is possible for a code to be stored (like knock sensor) that can impact performance with no CEL.

 

Well I have driven my dads is250 and I rarely rev it past 3k because of the low end torque, and I have checked codes with OBD fusion and theres is no stored codes at all, engine idle rpm at 650 and coolant at 195 F, I drove it to work today and it felt fine, less throttle lag and it had enough torque and no rattle noise, also from a stop and floored it, it accelerates like it should.