Need help please New Valve cover gasket

1998 Nissan Sentra GLE approx 148000 Miles.
I recently had the oil changed & they said that I needed a new valve cover gasket. Before having the oil changed, the engine was running fine (no stalling, no smoke etc). Their estimate for replacing the gasket was $175. I've done this job on my old dodge aries, so I figured I'd do the job myself. A

The first time I did the job, I forgot to use RTV sealent where the Haynes repair manual siad to put it, so i had to do the job again. Now I am getting smoke coming from back of the car and lack of power. This is most noticable in 4th gear, but noticed it in 1st today. There is also a faint smell of rotten egg coming from the exhaust -- not sure about that. The smoke is white / light blue in color.

When I got home tonight I checked the valve cover & some of the bolts were loose. How tight do these have to be, when I do the job again (still leaking oil around gasket drivers side) how do I keep these screws / bolts from coming loose? I think the engine is somehow causing them to unscrew.

I've already replaced the plugs and wires -- didnt know that Bosch plugs dont work well in Nissans. Will replace with recomended brand once oil leak / smoke issue is solved.

Valve cover gasket ---- $10
Spark Plugs ----------- $40
Wires ----------------- $63
experience ------------ priceless :rolleyes:

Any and all advice / comments will be greatly appreciated
Jon

loctite?

loctite?
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Thankyou Nismo. I'm taking the Sentra to the regular mechanic today for a oil presure test to find out where (why?) it's leaking / burning oil. A little out of my experience on the test. If it's just the valve cover needs to be tightened I will definately by some loctite and use before tightening the blts.

Jon
Feel like I'm :banghead: with the Nissan. Bought a gas sipper so I'd save money (fuel), but I'm spending more than that on repairs. Never and I repeat Never buy a leased car.
:banghead: Doh!
banghead: Doh!
:banghead: Doh!

not that bad, just do the job right. if you get a rubber gasket you shouldnt use silicone at all. the valve cover bolts should be around 10-20 ft lb. basically enough to put some pressure on the gasket but since you have an aluminum head, dont overtighten it or you will strip out the threads. and that is expensive.

not that bad, just do the job right. if you get a rubber gasket you shouldnt use silicone at all. the valve cover bolts should be around 10-20 ft lb. basically enough to put some pressure on the gasket but since you have an aluminum head, dont overtighten it or you will strip out the threads. and that is expensive.

Ended up having a trusted mechanic do the job. That way if I still have problems (oil / smoke) I'll have recourse. Obviously didn't do a good enough job the first time.
Blacks Tire Service in Monroe NC