I'm pretty familiar with the Infiniti platform in general but I have something that's kind of confusing/worrying me. My 2011 sedan is running fine, no codes or lights on the dash, but once the engine warms up it loses most of its power under 3kRPM..... The best comparison I could make to how this feels while driving is turbo-lag, but obviously this is an N/A car being a stock VQ. I've checked both MAF's and they're literally the cleanest sensors I've ever seen. I know there's a MAP sensor in the intake manifold somewhere but it's not throwing a code. My coupe ran great even when it was throwing a code for the MAP going bad.

Like I said, this is confusing/worrying me. I keep thinking this could be contributed to heat soak raising intake temps until flow is higher in the higher RPM range, but I never modified this intake system nor my coupe and the coupe never did this.....

Any thoughts? Thank you in advance for any contributions. I really hope it's not something with the transmission or torque converter...

 

Your best bet is to manually shift the car to determine if it's improper gear. Check your plugs also.

Lastly broken gallery gaskets limit the amount of oil going to the VTC phaser and this could be your problem. Either broken gallery gasket not advancing/retarding the phaser or a phaser that "slipped" and got stuck in a certain position and not adjusting as it should.

 

I always have it in manual mode, so that's not the issue. I've heard of the gallery gasket being an issue, but didn't know it could cause this kind of problem. I also had 250k miles on my coupe and it never had this issue. My sedan just rolled over 111k last week so I wouldn't have thought that was the issue otherwise. How hard is it to check the gallery gasket?

 

Checking oil pressure will help you determine if it is indeed a gallery gasket issue.

The lag bellow 3k RPM once the motor gets hot is a common issue on the G that doesn’t appear to have a definitive solution. There is an on going thread on it about it actually. Mainly seems to affect 6MT cars but it’s not limited to those cars only.

I have the issue myself and it’s really a MAJOR annoyance with the car. It literally feels like limp mode but once I hit 3k it snaps back to normal. Some members report a tune will solve the issue, which leads me to believe it is a ECU issue but I’ve done no actually diagnosing of the issue yet.

 

Where can I get an oil pressure sensor? I don't think this is the issue, but it won't hurt anything to check.
I've wanted to get a tune at some point so if the ECU really is the issue, I may just save up for a tune. It's annoying, but not something I'd sell the car over.

 

Here you go:

 

An electronic oil pressure gauge will let you know. You will need to compare your Idle Pressures To see if it's your gallery. Define out if the phasers armistice up you might have to remove both BTC covers while the engine is have top dead center in see if they lineup.

 

Thanks for the vids! I'll have to watch them on my lunch break lol

If the gallery gasket ends up being the issue, is it a big deal where I'd have to take it somewhere, or if you're competent you should be able to do it yourself?

 

You lost me at phasers armistice and BTC covers lol Care to elaborate? I haven't done much engine work so I'm not the most familiar with some things.

 

My apologies (talk to text)
I meant Cam phasers and VTC covers.


These phases are in charger of adjusting the cams in an advanced position or retarded one. OBD fusion has a plug in to check your cam angles.
To my understanding these angles should change with rpm from 0-127 degrees. I currently have my bank 2 stuck at 127 degrees and I suspect this is your issue as well.
I hope that I am wrong in my case being that I did my gallery gaskets/chains/WP/tensioners/etc 12k miles ago. This phaser is not part of that maintenance and these is no avoidance either.

You should look into OBD fusion to monitor these angles.

 

Gallery gasket is major surgery, challenging even for experienced wrenchers.
Whole front end of the motor (and car) has to come off.

Troubleshoot the other possibilities first.

 

That’s some great insight there BULL, I’ll have to remember to circle back and get some data logs to further investigate this.

I had a similar issue on the K20 VTC cam gear not advancing past 25* (whole reason I swapped the K20 gear into my K24 motor). Ended up being a locked up VTC. Lesson learned don’t purchase that particular part used.

 

So...oil pressure loss to the point where the cam phasers don't work properly doesn't set a CEL in these cars?

What a weird fu##ing car...

 

As mentioned previously, no one's really sure what the true cause of this issue is. But to your point, yes that would be very wierd for that kind of issue not to throw a CEL.

 

I've done some digging and I've found one thread (I forget what site it was on) where they solved this issue with new front wheel speed sensors. I haven't found any other thread with a pin-pointed solution. Several threads even go on to say that tunes didn't even work so I don't think it's the ECU alone either.

I'll check to see how much those sensors are. If I get them replaced, I'll update to let you guys know what the result is.