Noise at start up

[ComancheKid45]

Not a Comanche but my wife's 2004 WJ, 4.0 190k miles 15/40 oil

 

Seems like it has a dry start issue, it's taps and rattles for around 2-4 seconds on startup untill the oil pressure comes up. Is their anything you guys recommend I can add to the oil or anything like that to cure this?

 

I don't have this issue with the trucks or the XJ.

 

[89 MJ]

I have this issue with my MJ. It also rod knocks so it is the least of my worries.

 

Maybe try a high flowing oil pump. I'm not sure though.

[schardein]

My 91 MJ has done this since I bought it.  Let it sit a couple days and it will rattle for a good 5-6 seconds before quieting down.  It keeps on running good though.  I am doing a 4x4 conversion soon, and will swap  to a 1996 4.0 at the same time.

 

I don't know what causes it.

[jdog]

Can I ask why you're using 15/40 oil

What oil are you using in the mi and xj?

15 is a little thick for colder climates

[ComancheKid45]

2 hours ago, jdog said:

Can I ask why you're using 15/40 oil

What oil are you using in the mi and xj?

15 is a little thick for colder climates

 

Been running 15/40 in all my 4.0 engines for years, mostly for the zinc count ( whole other topic). It doesn't get that cold around here in South Central Pa, but maybe for a week or 2 during the winter.

[jdog]

How cold is cold to you? Anything below 40 id be looking at a different oil, there are other ways of getting zinc in there, while the video is probably a little colder then what you get it's still interesting to see how slow thicker oil moves