Nissan 370Z Forum - View Single Post - Loss in acceleration + throttle response ??

davidyan · 09-30-2009, 09:59 PM

If you're confident that the problem is isolated to the oil change, do the following:

1. check the oil level and make sure its full (but not overfilled). If you're low on oil (significantly), it could affect the VVEL system as it relies on oil pressure.

2. check all the parts you touched. Did you accidentally knock off any hoses or air tubes from the engine while working on the car? Is the dipstick inserted all the way in? Leaving it slightly out, creates a minor vacuum leak.

3. What oil weight did you use? If you used the wrong weight (typically too thick) it could create a small drag on the engine parts and decrease HP. Nissan recommends 5w30.

4. Very unlikely, but you could have a defective (broken) filter which isn't allowing enough flow. Are there any dents in the filter? The bypass mechanism could also be stuck. Its driven by oil pressure and at 3 - 4K RPM most oil filters fully bypass for maximum flow.

Basically, go through every step you did and make sure its right. If its all done correctly, and you still have the problem, I doubt its the oil change. I hate to ask, but did you do anything else other than the oil change?

Good luck and update us.

09-30-2009, 09:59 PM	#10 (permalink)
davidyan Base Member Join Date: Jun 2009 Location: CA Posts: 244 Drives: PG 370Z Sport 6MT Rep Power: 15	If you're confident that the problem is isolated to the oil change, do the following: 1. check the oil level and make sure its full (but not overfilled). If you're low on oil (significantly), it could affect the VVEL system as it relies on oil pressure. 2. check all the parts you touched. Did you accidentally knock off any hoses or air tubes from the engine while working on the car? Is the dipstick inserted all the way in? Leaving it slightly out, creates a minor vacuum leak. 3. What oil weight did you use? If you used the wrong weight (typically too thick) it could create a small drag on the engine parts and decrease HP. Nissan recommends 5w30. 4. Very unlikely, but you could have a defective (broken) filter which isn't allowing enough flow. Are there any dents in the filter? The bypass mechanism could also be stuck. Its driven by oil pressure and at 3 - 4K RPM most oil filters fully bypass for maximum flow. Basically, go through every step you did and make sure its right. If its all done correctly, and you still have the problem, I doubt its the oil change. I hate to ask, but did you do anything else other than the oil change? Good luck and update us. Last edited by davidyan; 09-30-2009 at 10:01 PM.