Valve cover questions

2000 XJ 4.0L


I replaced my head with an Alabama head 2 years ago, and at the same time installed a Crown Automotive aluminum valve cover.

The cover claimed to reduce valvetrain noise and dissipate heat more efficiently. I actually think the valvetrain noise is louder, but who knows.

The main issue I have with the aluminum cover is that the bolts keep loosening and causing leaks, even when torqued to spec. I found a stock stamped steel cover off an '01 4.0 and plan on replacing it with that.

I have a few questions:

The factory steel cover uses those metal inserts and plastic grommets to prevent over tightening of the cover. My cover did not come with these. The grommets are easy to find, but the metal inserts are next to impossible. I don't really see the point of them (the aluminum cover doesn't have them), would I be okay just using the correct size bolts and no grommets?

Anyone know the length of the valve cover bolts? I know the thread is 1/4" x 20.

I do not have the answer to you question(s) but what valve cover gasket you using? I have the aluminum valve cover and using a fel-pro valve cover gasket and have no issues.

My FelPro valve cover gasket came with those spacers and plastic clips.

MoFo said:

My FelPro valve cover gasket came with those spacers and plastic clips.

Click to expand...

Huh... i got robbed then :dunno: Haven't had any issues not having then either

The gasket is a Fel-pro. I also hate the oil cap that came with the aluminum valve cover. It comes off way too easily. When the bolts are tight the cover won't leak, but whenever I see a leak sure enough the bolts have worked themselves loose.

Are you using the original factory bolts? I may be wrong here but I haven't run across many SAE bolts/nuts on my '97, just metric. Maybe try using lock washers.

I'm using the bolts that came with the cover.

You can see the cover in this pic:




My main question is will I be fine using the stock steel cover without the grommets and metal inserts?

Which material is a better sound barrier, aluminum or stamped steel? My valvetrain seems louder with this aluminum cover.