Valv

Can I use a 3rd gen valve cover on a 2nd gen ?
I'd like to reduce engine noise, I believe the 3rd gen have insulation on top to reduce sound.

Since both engines are 24v it should be no difference, right ?

XLR8R

Really want to reduce engine noise?

- Get a couple more injection events in there!

xtoyz17

Everybody's a comedian....hardy harr harr.

Some of us like....well I guess I really can't think of a 2nd gen benefit over 3rd gen.

Jfaulkner

They don't have insulation that I'm aware of. (my 05 doesn't anyway) and no you can't use them because the CR heads use a different bolt pattern and the covers are not as tall since they have a rocker box with the wiring in them.

Valv

Jfaulkner thank you for your explanation, I appreciate it.

I guess I should have looked at it closer before posting. I thought the "hump" in front was something to reduce noise since they are so quiet.

Ronco95

Valv,

I have read that most of the 24V engine noise comes from the VP itself. You might consider wrapping it in a blanket to suppress some of the noise.

There is also a company that makes a series of blanket for the oil pan, exhaust manifold and engine top to reduce engine noise.

Some members have gone to great lengths to add noise reduction techniques to their trucks like insulation under the carpets and in the doors themselves.

Ronnie

xtoyz17

I'd say the majority of the noise in these motors is caused by the type of injection system. Same with the 12 valvers. Thats why when the duramax came out it was quieter than EVERYTHING. It has common rail...

duratothemax

yep...HPCR is what makes the engine quiet. All of the big three new diesels are CR and they are all quiet...

Jfaulkner

Blankets work also. All of our Cat C-15's have sound deadener on the sides, and one had the oil pan wrapped the trucks also have 1" thick foam with a foil cover on the bottom and sides of the hood and they are 1/2 as loud as my pickup even with CR.

Canadian24v

Jfaulkner is right, the third gen covers have no insulation but the valve cover will still bolt on. The rocker box portion or lower half bolts on the same place that a second gen cover bolts on. you would need a rocker box (spacer) from an '06 and up because they don't have the harness integrated into it. instead the harness is a part of the gasket like a 7.3L. Plus the valve cover is one piece instead of the older (2003 to 2005) style having a plastic part that covers the breather. I'm not sure if you'd have clearance under the cowel or not but this would be a great way to relocate the breather and help reduce some mess up front. If noise reduction is what your after I'd look into injectors, different spray patterns and increased number of nozzle holes does reduce the noise quite a bit.