Honda's periodically need them to quiet down valve chatter but I haven't heard much when it comes to VQ35's.

 

I don't think it is a common practice due to the shimming required and ntm the cost of the shims alone are pricey. Plus finding the know-how to do it.

 

As far as I know they are DOHC engine, that runs off timing change, from what I see in the service manual has no mention of valve adjustment, if I saw correctly they have hydraulic lifters on them. so no adjustment needed if they are making nosie, possibly the timing guide might be worn or the chain is stretch. you could add lucas oil stabilizer to quiet it down a bit.

 

The 3.0 owners manual suggests valve adjustment if it gets noisy. Anyone know what the cost on something like that would be?

 

I don't know about the cost, but the plenum must be removed to get to the RH bank. The Field Service Manual (FSM) lists the procedure to check valves for adjustment. Since I had my Valve Covers (VC) off I checked mine with an angled gauge. I bought a set of "suitable tools" for removing the shims off eBay from www.sirtools.com. It is named a "Valve Adjustment Kit" at SirTools.

The most labor intensive part of a check/adjustment is rear plenum removal and re-installation.

From what I am seeing, it is rare for VQ30DE valves/shims to need adjustment.

Are you experiencing any noise that sounds like tapping lifters when you first start the vehicle after sitting for over 8 hours that is leading you to believe you have noisy valves?

How many miles does your car have on the engine?

 

Valve timing and valve lash are two different adjustments. My 2005 has manual shims for valve lash. Manual says to adjust them if there is rattle when the engine is warm