New valve cover gaskets, bolts, and washers. Re-torque after first drive? (1 Viewer)

[badlander]

Just wondering if it is a good idea or not. Today was the first drive and tomorrow I'm replacing all of the coil pack boots and seals so I'll be in there anyway. Something tells me I should just leave them alone, though.......
The manual says nothing about it but that was always the norm with old school head bolts, etc.
Opinions?

 

[outdoorsman]

The is no reason to re-torque the valve cover bolts after a drive.

Some poeple think they get loose (back out) with time but they only shrink and dry up with time. After 15 to 20 years or 100k miles the bolts can be tighten down more. The better answer is to just swap the valve cover gaskets out.

 

[Jackland]

I wouldn't think you would need to do this if you replaced the gaskets and torqued to spec

 

[badlander]

Ok, I'm sold. I'll leave wellenough alone. I'll wait and then hit them in 30k or so.
Thanks guys.

 

[OEMGUY0720]

This was on my 06LX470 with 235k miles on it. Oil seepage. So I had to take out the whole intake manifold assembly and take a look. I replaced the intake manifold assy gasket (two sets orange color gasket, throttle body gasket and all upper o-ring fuel injectors seals). Upon thorough inspection I discovered that all the bolts on the valve cover were loose (driver side), that I could turn them by hand w/c was the culprit why there was oil seepage. Retightened them to factory spec. Wouldn’t hurt to just check if they are still on the correct Lb/ft spec even it’s just freshly replaced.

 

[planomateo]

Just wondering if it is a good idea or not. Today was the first drive and tomorrow I'm replacing all of the coil pack boots and seals so I'll be in there anyway. Something tells me I should just leave them alone, though.......
The manual says nothing about it but that was always the norm with old school head bolts, etc.
Opinions?

My valve covers weren't at spec and had some oil leak, tightened them back to specs, cleaned it up and hasn't leaked since.

Checking them isn't a bad idea in my opinion.

 

[badlander]

Ok, so I did check them and I'm glad I did. Several were about 1/2 to 1turn loose. So I re-torqued them all again and that is that.

Here are my thoughts on this, FWIW:

In most cases I don't believe the screws actually loosen themselve up by turning counter clockwise backing out of the holes as many seem to think. Whether it be caused by vibration, hot/cold cycling, or whatever, I just don't think this is the cause for these bolts coming loose.
My theory is this; there are 3 separate causes:

1) After initial installation of a new gasket, and after a hot/cold cycle or two, the seal will settle in and fully take the shape of the groove in the cover conforming completely into the groove. This process in itself would take some pressure off of the screws making them appear to have loosened. I think this is what happened in my case as I only brought the engine to full operating temp once before checking torque again the next morning. And just to clarify, when I torqued these the first time I didn't just go around once cranking them down. I started at 5 in/lb under and went around a couple of times until all were set and then went to full torque and went arount several times again until all bolts were solid with no further movement.

2) When first installed the seals have full resiliancy and provide constant push back pressure against the bolts. Over time, due to heat exposure and age, the resiliancy decreases as the seals get hard and the push back lessens, again making the bolts appear loose.

3) Same as above for the rubber washers on the bolts.

Thats my theory and I'm sticking to it!
And, as a matter of fact, if I get motivated today, I'll remove the intake plenum and mark the bolt heads on the passenger side to see if any rotation occurs over time.

So after this experiance would I recommend re-torquing these bolts?
ABSOLUTELY!