Hello everyone,

I just got around to fixing one problem and now another issue arises.

I have an 04 Z w/ 75,000 miles that I bought a month and a half ago. The Z has no mods on it besides a pop charger that I installed 3 days ago. I had to unplug the negative battery cable to reset ecu for pop charger No issues and problems with the Z until today.

Problem 1: So today after doing an oil change, I turned the key in the ignition to start the car. The car would start up normally then after one or two seconds the RPM's would drop close to 0 and the Z would either turn off or the RPM's would raise back to about 700-1000 then operate normally. This would happen every time I would turn on the car today (never happened until today).

Problem 2: After the oil change, I noticed that the Z would make a faint ticking/knocking noise when in Park and just warming up the car. The noise would go away as soon as I drive the car around and would normally come back after parking the car and sitting with the engine on. What could this noise be?

Besides these two issues, the Z drives perfectly fine. No dying out while driving, no loss in power, no smoke, no leaks or anything. This is why I'm more stumped on how the problems came out of nowhere..

 

Once you drive enough and let the ECU learn, it will stop doing this and idle normally.

 

For the ticking/knocking noise, I noticed that it only happened when I start the car and the car is warm. I noticed that the ticking didn't happen while on Park when I started the car when it was cold. The ticking noise is very faint and goes away when driven.

 

For the ticking/knocking noise, I noticed that it only happened when I start the car and the car is warm. I noticed that the ticking didn't happen while on Park when I started the car when it was cold. The ticking noise is very faint and goes away when driven.

 

its the gas ur using.

On the west coast our gas is so watered down, our Zs are always on the knock sensor, barely squeezing by on the octane. Back east and in the south, the 91 is a better quality and they also sell 93 octane a grade higher than 91. Fill your car up 1/2 with 91 and 1/2 with 100 octane racing fuel (76 in cali carries it) and see if that makes the knock go away, if it doesnt take your car to get checked.

I also saw your oil change problem, if it still continues do another reset on the ECU like you did before with the popcharger or just drive your car for about 50 miles and the ECU should recognize the new oil.

 

Thanks for your reply. I finished that tank of gas and got another full tank of gas somewhere (Chevron). Same thing, the faint ticking noise is still there during low RPM's. I have no idea what it could be. It happened after the oil change. The oil level is correct and everything went well.

The Z runs fine besides the ticking. No vibrations or abnormal idling.

I went from 10w30 Castrol Edge w/ Mobil 1 filter to 5w30 Castrol GTX high mileage w/ a microgard filter.