The Nissan Path

Has anyone changed the oil pump on the 4.0L? Do both oil pans have to come off to change it? I know the FSM says they do but I wanted to see if anyone has any shortcuts.

Thanks

Yes, both have to be removed. If you are replacing it because of low oil pressure, it may not be the oil pump. There have been issues on a number of VQ engines causing low oil pressure due to failure of the oil gallery cover gaskets on the back side of the rear timing cover. See link:

https://www.motor.com/wp-content/upload ... E_0116.pdf

smj999smj wrote:Yes, both have to be removed. If you are replacing it because of low oil pressure, it may not be the oil pump. There have been issues on a number of VQ engines causing low oil pressure due to failure of the oil gallery cover gaskets on the back side of the rear timing cover. See link:

https://www.motor.com/wp-content/upload ... E_0116.pdf

I saw that article. I'm going to be changing lifters on the engine and I have the same problem with the oil pressure that others do. Fine when the engine is at or above 750 RPM but nearly nothing (3-5 PSI) below that. If it was an easy job I was just going to swap out the oil pump while I was taking everything apart but it doesn't sound easy. I'll check the oil gallery cover gaskets while I'm in there but I'm not really into removing the final drive, disconnecting the steering and all the other prerequisites to changing the oil pump. Thanks for your help.

You do know that the lifters are solid bucket tappets and not hydraulic, right?

Yep. They're knocking like hell. Probably because of the low oil pressure. I'm not looking forward to it.

Well, unless there is a clearance issue, there is no need to replace the lifters, which is a pretty big job in itself. You may just need to fix the oil pressure issue. The lifter noise is more likely NOT due to excessive clearance and more likely due to valve train clatter due to insufficient oil pressure to the timing chain tensioners and/or variable timing gears on the intake cams.