Have a 2000 with 197K on the clock and it starting leaking from the drivers side valve cover. Read through alot of threads getting ready to replace the gaskets. However, I noticed a few people comment that when they did it the valve cover bolts were very loose.

Checked mine and they were very loose...I imagine a couple could have been removed by hand. Tightened up all the bolts I could get to without removing the intake and...no more leaks.

So, before you go tearing into things do yourself a favor and check the bolts 1st.

ha such a logical thing to do, since owning my rig I've read a gazillion threads on this site and knowing the vcg issues it was job id put on "the list" way near the bottom but nvr once considered checking bolts to see if that would fix the issue. Sometimes the simplest solutions can be overlooked. Thanks for post, will check mine today!

Yeah tightened mine about 50K ago, still not leaking. I tightened them by "guess hand feel" instead of torque. 330K on the motor. I have the gasket set, but don't want to tear it down unless needed.

Well, here's my two cents on this. To get to all the bolts, the plenums need to come off. Once you've bothered to take the plenums off, you could do what you did and just tighten the bolts or you could take it to the next level and replace the valve cover gaskets, replace the spark plug tube seals, replace the cam plugs and reseal the half moons. The valve cover gaskets are just one area oil can be leaking from so tightening just the bolts aren't going to stop a leak from the cam plugs or the half moons. The spark plug tube seals aren't usually an issue but it's good to replace them while you have the valve covers off.

Doing the actual replacement of the things I mentioned is the only way to insure you won't still have leaks and not find yourself doing all the same labor again. Sometimes you are rewarded by cutting corners and sometimes not.

lol, unless you mess something up. I had to spend a couple hours breaking out a half-moon that was JB-Welded in place and cleaning up the head mating surface. You never know WHAT you're going to run into. And what happens when you've just replaced all of that a year ago, and those fasteners loosen/you start getting the weeps again? Nevermind that I've not seen a single person say they did All of them, just the ones that could be reached without disassembly.

Yup, full replacement is smart... but sometimes just a few minutes of time to hit the fasteners that are access able is smarter, especially as a first step. Not much to lose through that course of action, extremely low time investment and risk, zero cost.

I’ve read this before but how many fasteners can you even reach on drivers side?

I got to at least 4 and maybe 5 if memory serves....

Also there is a pattern specified in the fsm for tightening the bolts or the valve covers may end up cracking.

Harbor Frieght has a 1/4 torque wrench they sell some times for 9 dollars here in socal. For me it was worth the money as I am used to working on old cast iron and did not want to strip things out.

The bolts will keep backing out.

Wow, you're previous owner was an idiot. They JB-welded a half-moon into the head? That's criminal.

In regards to only tightening the bolts you can get to, that's a mistake in my book. Like @spartacus mentioned, that might lead to a situation where you accidentally crack your valve covers. But hey, if it works to stop the leak, it works.

I feel if the job was done right, using a torque wrench to tighten the bolts evenly and in sequence per fsm, bolts should not back out.
I think what happens is the vcg and that rubber under the vc bolt washers break down and shrink over time. Heat, cold and oil breaks them down. You could get away and just tighten the bolts down. However dont do it too long over time as you can bottom out, and snap the bolts in the head.

Is it of any use (and not harmful) to use Loctite blue on the bolts when putting them back in after gasket replacement?

great advice OP!

The valve cover bolt washers are a sort of rubber crush washer that will hold the bolt so you shouldn't need to. When they get old and hard they lose ability to serve the purpose. I usually need to re-tighten every 6 months.