washers and nuts for valve covers

[DaddyGlenn]

Is there anything wrong with using M8 washers and nyloc nuts from my local nut and bolt store on the valve covers instead of the pricey Porsche spec ones?

The washers are a little larger in outside diameter than the Porsche spec but fit just fine.

[304065]

Yes, most local washers do not have the crush resistance that the Porsche ones do. They have a very specific chemical composition and hardness that is actually set out in the parts manual, and will not deform under torque like the hardware store variety. Also, you want the correct diameter-- too large an OD will lead to leaks and improper sealing against the valve cover.

It's hard enough to make the covers seal correctly WITH the right stuff. Remember to use a torque wrench and do NOT overtorque.

[DaddyGlenn]

So I'm ok with the nylocs?

[burgermeister]

I think the aluminium crush washers need to be correct. Using other nylocks just saves you money ... and there's nothing wrong with that.

I have successfully re-used crush washers and nylocks on all but the bottom row of nuts on the exhaust side. Most of those started dribbling - makes sense, they sit below the oil. It's not very difficult to go after a leaky nylock after the fact.

[rusnak]

I think the aluminum washers are a silica aluminum, which is slightly harder than aluminum. I think they used to be available separately, but I haven't pursued it. It's like trying to buy spark plug washers separately. It's a great idea, but most people don't do it, so they are not commonly available separately.

[911pcars]

At a recommended tightening torque of around 6 ft. lbs. (valve covers only) as opposed to the normally recommended 17 ft. lb. for an M8 fastener, the aluminum washers hardly crush, but the softer, the better.

If you want to make sure it doesn't leak, apply some Loctite 574 on the threads before installing the Nylok nut.

Sherwood