tcturbo76- To save yourself a lot of time, a headache, and having to witness a thread highjack by three guys with really big egos, I strongly recommend you PM Q45Tech. While I don't necessarily agree with everything he posts, way more often than not he's spot on and he has decades of experience. He can point you in the right direction.

 

Wow, I sure was bored today, glad you guys gave me something to do.

If you've got something constructive to say without attacking someone else that actually helps the OP, feel free to post. If not, keep it to yourself.

This is your one and only warning, keep it on topic and no personal attacks.

 

Just in case everyone forgot what the actual "original post" was.

 

Process is fully described in detail in FSM engine section.
Nissan doesn't waste space by describing things that never need to be done, so you can assume this process is common.
Just that owners don't want to pay the $1,000 so they learn to live with it.

I don't accept/read PM nor emails nor phone calls nor letters.
Life is to short to be albatrosed by unsolicited communications.

 

This is not a "common" thing done on the VQ's but is good to do at ~100k miles or so.

I had to do it when the new heads went on my motor after it was built.

 

I would think you never need to do it unless it's needed.

If it was a scheduled type maintance, it should show up on the service recommendations. But I haven't looked to verify.

Makes sense that an adjustment has to be done on new heads as every set of new or rebuilt heads will "probably" require them to be setup/adjusted.

 

Buckets/tappets wear over time – so eventually adjustment is going to be needed… but as Q45Tech stated, most ppl don’t want to spend the $$$$ to get it done. As to how many miles before valve job is needed – I’m sure it varies, but the G has been around since late 02 so it’s no surprise that we will be seeing these types of maintenance/repair items more and more on the forums. (this is a general statement, doesn’t diagnose the OP is this thread).

 

From what I've read from the maxima forums (VQ30/VQ35), I don't think I've read more than a handful of posts regarding valve adjustment. It would seem that this type of repair is rare (thank goodness).

But it's reasonable to think that this type of adjustment might be needed. After all, engines are mechanical things that have parts that fail.

 

I guess it depends on your source - I based my post from the info shared by Q45Tech and Howard @ Technosquare... both of these guys know a thing or 2 about Nissan engines.

As stated a couple of times, the reason you don’t see much of it doesn’t mean its never needed - it's just as (if not more) likely that ppl don’t feel the need to spend 1K+ (and often times even though valves do need adjusting, there isn’t much harm being done so not spending the money is more often than not the choice ppl will go with... but again, that doesn’t mean the problem is non-existent.

 

I said it "could" be needed and said it's more of an uncommonly needed procedure vs common.

I'll quantify further. From what I've read, it's very rare that someone chimes in with valvetrain noise, determines they need and adjustment and choose to avoid it because of the cost. In fact, it's relatively rare that I'll read a post about noisy valvetrains on the VQ powered maximas. And the VQs have been out since late 1994' (if in fact the VQ30 shares a similar valvetrain dohc valvetrain setup) And there are plenty of VQ30 motors running 100,000 - 200,000 miles +.

Are there times when it's needed? Sure. Are there times that people choose to avoid it? Yeah, I'd say "yes" to that too. But are valvetrain adjustment problems common to those that are still running their oem setups? I'd have to say "no". Based on the degree of difficulty that Nissan choses to make the adjustment, in my OPINION, I'd say they tried to engineer this valvetrain not to require adjustments if at all possible.

An Integra GSR for instance is a very well built motor. But they do require regular valve adjustments as per the service manual. And that's why they designed their system to be easily adjustable w/o the requiment of bucket shims.

Our only contention that I can see is agreeing on how frequent this adjustment is really needed. IMHO, the need is more engine specific than the amount of miles a type of engine happens to have on it.

EM-11 of the manual has a decent procedure for diagnosis engine noises and states to repair/replace if necessary

 

I just reviewed the maintanance schedule from my manual.

It DOES mention valve adjustment. But it doesn't have any scheduled mile intervals. Only a notation pointing to note #5

Note 5 says "If valve noise increases, check valve clearances". Which seems to imply that if you have an increase in noise, then this might be something to look at (like what the OP is going though if valvetrain noise is the case here).

So Nissan is stating that only a noisy valvetrain warrants further inspection. Now that's not saying getting your clearances checked/adjusted is a bad idea. Just that as far as Nissan goes, there is no scheduled service (as their design seems to confirm) unless there is a problem (as the OP might have).

Now referencing my post above, since most members of the maxima forums (and here) are running their oem valvetrains and since they have not reported any great amount of problems, I'd have to assume (correctly or not) that valvetrain related adjustments are relatively rare for the VQ powered V6

 

I agree. I spent 6 years of my life on Maxima.org and fiddling with VQ30s. Never once have I heard of someone needing to reshim the lifters UNLESS they were revving the crap out of the thing 7,200-7,700rpms and needed stiffer valve springs or when they added cams. Additionally, I have yet to read about someone reshimming the lifters on a VQ35 whether is be a Maxima, Z, or G.

My VQ30 had 117K miles, around 300 1/4 miles passes, and was revved 600rpm higher (7100rpm vs 6600) than stock for the 2 years that I owned it. That motor received a far harder beating than my VQ35 does. Both motors sound the same with the hood (ie noisy, mechanical, and ticky). The VQ30 never had valve noise and nor does my 6 y/o VQ35 with 71K miles.

Like you pointed out in the recommended service schedule, there is a recommendation to adjust the valves *if warranted*. That same exact statement was in my 1996 Maxima owners manual. Oddly, the statement isn't in my wife's 98 Legacy GT owners manual, though reshimming the valves is quite common job after 100K miles on the 2.5 DOHC boxer. Go figure

It sounds quite possible that the OP is having a lifter issue, however, these types of issues are not the norm for the VQ series motor whether they have 30K miles or 200K miles. I've been around a lot of VQ30 and VQ35s with 100K+ and I haven't heard lifter/valve noise. I've heard lots of loud injectors though.

 

935 miles and the noise hasnt subsided.... MPG seems better. I have noticed though, at an idle, at a stop light my heater doesnt blow warm,then when I accelerate I get heat. WTF??? Any link to this and my noise???

 

Trying to diagnose a "sound" over the Internet is truly impossible... even giving a sound clip to determine "similarities" is not a definitive.

Compounding your situation with further developments (heat in cabin) only further deters the Internet "diagnosis" because the two issues may be totally unrelated (even though you might get a handful of supposed "expert" opinions").

Is there any reason you don't just take the car to an experienced professional and have them look, feel and listen?

You are bringing multiple symptoms to the thread and none of them can really be diagnosed here.

 

No good reason, just stubborn...

I just thought I would mention my problems here to see if they were common with these cars.

I appreciate all of the help I've received from you guys.