over torqued valve covers?

[slater]

What could be the worst case scenario if a person were to over tighten the lower valve covers. I torqued them down (new 1/4 " torque wrench) with new gaskets, and they still leak like crazy. I took a wrench and tightened them a little more (didn't crank on the thing, just tighter) and the leaks have all but stopped. Is it bad to have these too tight? I understand it could cause more warping on the covers, is that the biggest of my worries?

[kqw]

Yes, over torque those covers and they will become worse. What value did you re-torque the covers? On the Carrera's the setting is 6 ft/lbs and some folks torque to 6.5 ft/lbs without issues.

On you next oil change, pull the covers, place on a flat piece of glass and check for warpage. if it's not whacked out, you can sand them down.

Once you pull the covers you will need to replace the nuts also.

[aigel]

If you have thin gaskets, you would have to go nuts on the torque to warp things. If you have thick silicone covers, there is more room to introduce warping, if you overtorque. But do not worry, warping can be taken out again, by machining / sanding the covers flat later.

The main issue, when looking for a leak free cover is to get the nuts all torqued at the SAME value. So, if you want to try more, let's say 12Nm instead of 8Nm, that should be no problem. But you want to apply that with your torque wrench, not by hand!

The torque spec for the valve covers is derived from what's going on with the gasket. It is not a torque spec that aims at the fastener. (Stretching, clamping etc.) From the fastener point of view, the nut is under-torqued. I would think that that's the reason why it is a nylock. That way it won't come off, even at a low torque.

Hope this helps.

George

[kqw]

What george said.....

Question...Where are you leaking from? is the gasket wet or is it seeping from the nylock nuts?

1. Check the covers for warpage
2. Make sure you didn't pinch or tear the gasket on installation.
3. Nylock nuts are not seeping.
4. When I torque my nuts, I use a staggered patern from the center out.

[aigel]

What KQW said. It is important that you work your way from the inside out. Some people cris-cross in an X type motion, I usually just take it in a spriral motion, starting with one of the inner studs and working my way out. And yes, it may help to at least get the nuts snug first, in the same routine, before final torque.

George

[randywebb]

I wonder how much of the torque deforms the nylon inserts rather than stretching the stud/deforming the cover? They are full inserts as I recall...

Anyway - it's a good idea to sand the covers a bit each time. Search button will show you procedure - some of the post threads will also have my name on them if you need to add terms for filtering.

[aigel]

Randy:

Maybe I misunderstand what you are saying. I wanted to clarify that the threads of the nuts are metal. The nylon part is only on the top of the nut.

Cheers,

George

[randywebb]

OK. I thought I recalled they were all nylon.