How tight should valve cover bolts be?

[jcook100]

Hi there,

I was just installing my valve covers and tightening down the bolts when the threads stripped out of one of the holes on the lower intake manifold. Now I have to go get it drilled out and have a helicoil placed in there. My manual said that these bolts should be tightened between 3 - 6 foot-lbs, but even with my torque wrench set at about 4.5, it was too much force and the threads stripped out. So what did I do wrong? My torque wrench is from Harbor Freight, so maybe I need a better one? Or should I just tighten the bolts by feel? I already had one of the thermostat housing bolt holes strip out, so I am pretty frustrated with this issue. I am now scared to tighten any of those lower intake bolts!

Also, am I good to reuse the same gaskets? I will have to remove the lower intake again (sigh) so can I reuse that gasket? And the valve cover ones too? I assume so, but just want to check. Thanks.

 

[RonD]

A torque wrench that can do over 100ft/lb is no good under 20ft/lb that's when you need a inch/pound torque wrench

4ft/lb would be 48in/lb, less than "snug", finger tight then maybe 1/4 turn, and use lock-tite on bolts with torque under 15ft/lb

If your valve covers are pressed steel(thin), or plastic, then over tightening causes leaks
Valve covers have no pressure inside, nothing will FORCE oil out, its all splashed oil and gravity that would cause oil to seep out, so you just need a clean flat surface between cover and head to get a good seal, thin coat of RTV doesn't hurt to fill in the "less that flat" sections

 

[jcook100]

The lower intake manifold gasket is metal with rubber inlays. The valve cover gaskets are some sort of plastic-rubber combo. Am I good to reuse them?

You are saying to do finger-tight then a 1/4 turn? Or just re-do with an inch-lb torque wrench?

 

[RonD]

What engine do you have?
2.3l, 2.9l, 3.0l, or 4.0l

Rubber gaskets are usually OK to reuse but I prefer cork gaskets, if available for your engine, cork swells up with oil contact inside the valve cover so is "self sealing" as time passes, but these can not be reused after a year or so, they get brittle
Use RTV on both sides of either


If doing things to spec then use in/lb torque wrench
Once you have been doing engine work for awhile you will get a feel for what's needed as far as tightness in these low torque bolts
Water pump bolts are the same, there are alot, and they are not high torque because there are alot, lol, every inch or two there is a bolt, and people often break theses by over tightening, or strip the holes

Your valve cover bolt hole may have been cross-threaded in the past, easy to do, and this time it just stripped out, so might not have been too much torque this time

 

[jcook100]

Thanks, RonD. You have helped me several times now and I really appreciate it.

I have the 4.0L.

Looks like I need to get an inch-pounds torque wrench. I used a big one and that it was did it I think.

 

[RonD]

Yes, any bolt head under 1/2"(12mm) shouldn't be tighten with full size torque wrench, there is just too much leverage with the longer handle

 

[Dirtman]

I don't find any reason to torque valve covers, just use a 1/4" ratchet and put them on with just a little snug once they are all the way in.