Hello,

I am driving a 06 G35 coupe, with 86,000km on it right now. The car is auto.

Recently I started noticing that the engine is less powerful that it used to be. Specifically this can be felt when going up hill or reving the engine.

I've changed the oil and drive belts since but the problem remains.

I'm not sure how I can diagnose it or quantify it. Any ideas? I'm tempted to do a 0-60 test!

Thanks!

 

Try this first, made a slight difference in mine, even tho it already drove very nice for me.

https://g35driver.com/forums/engine-...resetting.html

 

Try a transmission Flush./Plugs, wires. Its general maintenance that will keep your car feeling peppy!

 

A transmission flush was done less than a year ago! (only 13,000km in that year) Also, it's not that it feels slightly weaker.. it feels *significantly* weaker... more like a 4 cylinder engine.

With regards to resetting the ECU, I am worried if I do that any error codes may be erased.. making it harder to diagnose.

I am thinking it may be related to the spark plugs... I also looked at the engine control system service manual, and it listed these as the most likely causes (all ranked 1).

1. Ignition | Incorrect ignition timing adjustment EC-70
2. Accelerator pedal position sensor circuit EC-502, EC-594 , EC-601 , EC-615
3. Intake valve timing control solenoid valve circuit EC-194
4. Cranking | Battery SC-4
5. Generator circuit SC-22

What is strange to me is that so far I have not noticed any decrease in the fuel efficiency.

 

Your best bet is to find a certified Nissan shop in your area and have them diagnose the problem.
Let them do the leg work.

 

My issue is not if I should take it in or not. I just want to understand the problem so that I know I'm not damaging the car by driving it. The dealership is 40mins/30km away. I have an appointment for tomorrow morning.

Today I noticed something new. There is a grinding noise when I switch from R to D or D to R..

 

tune up and transmission flush?

did the dealer tell you what the grinding noise was?