2008 G37s 6mt Accerleration

[JDeeze]

Hi,

I recently purchased a 2008 G37s 6mt and I must say, that car makes driving a great experience! The car had ~19k mi when I first bought it. I did run into an issue around 21k mi where the slave cylinder went bad and had to be replaced. I was pretty upset, but got over it since it was completely covered under the mfg's warranty.

1.) Has anyone ever heard or experienced a slave cylinder going bad so quickly? Could the previous owner have possibly driven the car so hard that it caused this type of failure?

The real issue that I would like to address is the car's overall performance. When I first bought it, the car had amazing acceleration and speed!!!! Especially when you hit 3rd-5th gear, it felt like when you hit the gas, the car suddenly just let loose an explosive burst of speed!!! Lately, I've noticed that it doesn't have quite the same "kick", especially in 1st gear. If I'm at a stop light and begin to accelerate it seems to have some hesitation before accelerating. The technical spec on the car claims 0-60mph in ~5.5s, but I can tell you mine feels more like 0-40mph in ~5.5s.

Technical Info:
When I had the slave cylinder replaced the Infiniti dealer performed a Multi-Point Vehicle Inspection and noted that the In-Cabin Microfilter and Engine Air Filter were dirty and recommended that they be replaced. I did not replace either at that moment. Based on my reading it sounds like the Engine Air Filter plays a big part in vehicle performance and efficiency. The inspection was performed when my car had ~21k mi. It now has ~23.5k mi.

2.) I plan to bring it in for service this week (replace engine oil and filter, engine air filter, etc) and wanted to know if there are any other recommendations to improve my car's performance?

Based on my research, it's recommended to:
-add fuel injector cleaner every ~3-5k mi (although this is debatable based on the Owner's Manual)
-keep spark plugs clean
-keep tire air pressure ~3psi higher than recommended
-keep all air filters clean
-keep clean oil in the engine

Thanks

[audtatious]

Welcome to NICO

Parts go out on a car, nothing new. Brakes, clutch, etc. are all daily use parts that you cannot assume will last a long time before maintenance is needed. While 21k seems short it's not really something to get upset about and without speaking to the prior owner there is no way for you to know what type of abuse the vehicle may have had.

The engine is an air pump and the more efficient this pump works the better performance you will have. The in-cabin microfilter won't cause a performance problem. Having dirty or clogged engine intake filters can cause a problem with allowing the engine to breathe. While I would not think there would be that much dirt in a filter at 23k miles (to me...because most of my travel is highway) it's dependent on where the car has been driven. If a car is driven in a dusty place then you will need to replace the filters quite often. Pull the filters and replace them. It won't hurt to do so.

What kind of gas are you using? While the G will run on cheap gas you won't have the same performance as 91+ octane.

for the rest....

- Higher quality fuel has detergents already, no reason to add injector cleaner
- Change spark plugs based on factory recommendations (or a tad earlier) otherwise there is no need to mess with them
- Higher air pressure than normal may make the car feel lighter and it _may_increase mpg slightly. It will hurt handling performance and may lead to center-tire wear
- Yes, regularly replace air filters based on factory recommendation or earlier if needed
- Follow standard oil change schedules as described in the factory manuals

[joe603]

Nissan slave cylinders seem to suck...I had mine replaced on my 05 G35 coupe.

[JDeeze]

Hey thanks for the feedback guys. I did take my car for service and had the engine air filter replaced. I mentioned the hesitation in 1st gear and they mentioned that it felt like the clutch does feel worn. Their recommendation was to not hit the gas too hard before completely releasing the clutch. It does seem to help and feel less hesitation when I apply just the right amount of gas. Every car I've ever owned was a manual so I thought I knew what I was doing, but I guess every car requires some adjustments to how you handle shifting...go figure

Thanks again

[audtatious]

I've driven a couple of 6mt's, both stock and boosted, and have not had to do anything special with the clutch. Maybe it is simply that worn and not holding.

[joe603]

There was a "safety mechanism" in my 05 that would not let the car engage the clutch if the engine rev'd past 4k RPMs. The pedal would just stick to the floor. Between that and the lightweight flywheel causing extreme powertrain noise (sounded like a dump truck) It turned me off enough that my next G was an AUTO...