2002 Q45 loud knocking noise on startup

[carnut]

Hi Guys,

My 75k miles Q occasionally was making knocking startup noise (sounded like valves), which went away when hot and I was told they are somewhat normal.

Now after not driving it for a couple of weeks the knocking metallic noise was so loud that I was afraid to drive the car. Car has full mtc and oil changes about every 3.75k miles since new, but has been burning some oil/blowing smoke on startups (I posted about it a while back on infinitilist - btw, what happened to infinitilist?)

Any ideas of what's likely to be and what to do with it?

thanks

George

[MattB]

How much oil is it burning?

[elwesso]

i dont know if you can do this, but if you could post a video we can really easily tell what it is....

If you cant host it yourself just email it to me.

[carnut]

It's burning about 1QT every 2-3k miles, so I typically top it up once between oil changes.

Good idea with the video! I'll post it on youtube as soon as I take it and will let you know (so I don't have to host it myself and mybe it will become a hit like the mentos and diet coke video?

[ScottJackson]

I'm suspecting a timing chain tensioner is leaking down. Nothing more than a guess at this point though. What kind of oil filter are you using? Some cheapie filters like the orange Fram ones don't have a decent anti-drainback valve. A better filter like Wix or even wal-mart brand Tech2000 will do a better job of keeping oil-bleeding rattles to a minimum.

[elwesso]

just email me the video and Ill host it so we dont have to deal with youtube!

[carnut]

Oil filter - I use original Nissan, so hopefully it's a good one.

Wes, I've just posted on youtube before seeing your message (thanks for the offer anyway). Here is the video:

http://www.youtube.com/watch?v=FAOo1I4x3nQ

Actually I haven't driven the car since the noise started to be so loud, it does not go away completly within the couple of minutes of running it

[Jesda]

Oh god, that sounds awful!!!

[elwesso]

Sounds like lifters to me... Im not sure how youd fix that but it sounds like that... The rhythmic ticking sounds more like lifters.. if it was a chain tensioner it would make more of a "can of marbles" sound.

[Q451990]

I agree... lifters (or for the purist HLAs). Sounds really rough... I might look for the enviroloution flush that has been mentioned here before.

Heath

[carnut]

OK guys, thanks for the diagnose, a quick search for the cure returns:1. Put 1qt of synthetic ATF fluid, drive carefully < 3000RPM (for 1 hour or 3000miles depending on a source), change oil again, see if it goes away2. Have a dealer do BG or Bilstein or Envirolution flush for $80-$1503. If 1. or 2. does not help change all the 32 HLAs as even if only one is stuck you can't tell which one (that's the solution I did not like too much considering a statement I've read: "it's ususally cheaper to change the complete engine"

as the valves are made of titanium they are probably not cheap to replace once damaged, so plugged up HLA is not very good in a long run... I'm also not quite sure about any side effects of ATF...

I'm thinking going to the dealer for #2 unless you have any better ideas, thanks again

[Jesda]

The sound is a much lower tone than HLAs, which even if they fail only sound like tapping your nails on glass. This sounds much worse.

[ScottJackson]

Maybe piston slap? First thing I'd do is take off all the belts in the front to make sure it's not something like the power steering pump or fan clutch (don't think it could be, but it's an easy thing to eliminate those small chances). Then I'd get a length of hose that I can hold up to my ear and the other end around the motor to hear where the noise is loudest. That'll a lot of times help narrow it down. Yeah, try the ATF in the oil first. I don't think it matters if it's synthetic atf or not. ATF is around a 5 weight oil with a lot of detergents in it. You could probably do a stronger solution than the 1 quart in the oil mix for a bit more effectiveness.

[Q45tech]

Study [download a FSM] the new 4.5/3.5 engine you will find direct cam driven SHIM-bucket lifters [shims to set the lash].......just like Lexus/Toyota/BMW. Necessary to measure the worn lash and select and replace noisey shims with too much clearence.....................

HLA were dropped to reduce cost/friction.

The new engine is much less forgiving [oil rings] than the old 4.5/4.1 so skip the ATF and only use BG Quick Clean for engines and follow directions precisely!

Follow 3750/90 day oil change precisely even more importand than on older designs.

[elwesso]

i agree iwth tech, im not so sure about the effectiveness of ATF... Better to use something like quick clean that you know is gonna work...

[xerexabante]

try to use thicker oil, this will quiet your motor at start up. the noise are valve tapps. i get it in my f50 as well. i am using 10-40. might help your problem. the real fix would be getting your valves re addjusted. shim type vavles suck of you are the owner. makes a lot of money for the shops. just to take the cam shaft off 10.6 hrs. does not include labor on reshimming, plus parts.

VALVE CLEARANCE STANDARD

HOT Intake:...............0.32 - 0.40 mm (0.013 - 0.016 inch) Exhaust:.............0.33 - 0.41 mm (0.013 - 0.016 inch) COLD * Intake:...............0.26 - 0.34 mm (0.010 - 0.013 inch) Exhaust:.............0.29 - 0.37 mm (0.011 - 0.015 inch)

[carnut]

I will poke around a bit more with a sthetoscope to see if I can locate the source better (will have to wait a week as I'm flying out of town tomorrow) - would be nice if it was something outside of the engine (e.g. someone else had a loose exhaust bolts in one of the posts about a Z car)

But now I'm confused regarding the valves (assuming noise is valve related).

Does it mean that Nissan stopped using hydraulic valve adjusters (HLAs) in 2002+ Q45 engines? So do the engines now require periodic valve clearance checks and adjustments? (I used to do that on older cars, but I thought those days were over). So if that's a mechanical (not hydraulic) adjustment, no engine flush (BG, Envirolution etc) can make a difference as there is no plugged HLAs to unplug?

[elwesso]

Yeah i think what your saying is right, i didnt know the VK didnt come with HLAs, pretty weak!!! Still, im not sure youd need a valve job after 60k or so, but im not sure... Id think about asking some of the VQ guys if theyre having to do that...

[maxnix]

1.) Does it mean that Nissan stopped using hydraulic valve adjusters (HLAs) in 2002+ Q45 engines?

2.) So do the engines now require periodic valve clearance checks and adjustments? (I used to do that on older cars, but I thought those days were over).

3.) So if that's a mechanical (not hydraulic) adjustment, no engine flush (BG, Envirolution etc) can make a difference as there is no plugged HLAs to unplug?

1.) Yes.

2.) Yes. I think they tip in and out without removing the camshafts like on the old FIAT engines. Unfortunately the Alfa engines required removing the camshafts and keeping timing corect. Don't know what the interval is on the VK45DE, but on the Alfa four it was about every 12K. It is the very best way to actuate valves in a high rpm engine, but I'll stick with HLA for maintenance purposes on the street.

3.) Maybe yes, maybe no. There might be a blocked oil passage somewere. I would have to suspect your OCI practices. If it were my car, I would Envirolution the engine immediately after replacing the shims, convert to M1 oil (probably 0W - 40 at first) and use the M1 filters from Joe.

[elwesso]

good suggestions brian.... I will check the VK45 FSM when I get home tomrrow night....

[Q45tech]

LS400 has used buckets since day one.................if you are not meticulous with oil changes you get to do the shim changes frequently..........mostly a few in the rear cylinders. You must measure all 32 but rarely change more than 4-8.

This is where synthetics changed frequently save you money........either the cam or the shim must be worn to make the noise. The shims are softer than the cams. As they cost the least. You don't need to remove cams to change shims.

This change from HLA to buckets probably increased power by 4-6 HP. Takes lots of these tweeks to power up to 330 from 280.

Remember the new 4.5 wasn't sold until 2002 so 4-4.5 years doesn't tell you the wear rates. YET.

And you won't be able to find JDM take outs for years yet in quanity.

[xerexabante]

if you have the noise just on first start up i bet you it is the valve shims. try to use thicker oil. it is not a real fix, but it woild prolong your wear on your cams and your shims. add some addetive i like Lucas, try it would not be a bad idea. make sure it is for your oil in the engine.

[Q451990]

This is where synthetics changed frequently save you money........either the cam or the shim must be worn to make the noise. The shims are softer than the cams. As they cost the least. You don't need to remove cams to change shims.

Wow... great informaiton. Makes me feel even better about my strategy for our G35.

Heath

[carnut]

I'm back and here are the observations after pokeing around with a stethoscope:

1. The noise is coming from the back top of the engine, confirming the valves diagnosis and statements that shims are likely needed in the back2. After several minutes of idling the noise almost goes away and is replaced with a quiet ticking. Revving the engine up brings back some of the noise. (This is opposite to what factory manual says, which indicates noise after warm up to be likely associated with valves. But the manual could be wrong). 3. Manual provides description of the shim changes, but using some 2 Nissan tools without removing the camshafts. Hopefully faster than the camshaft removal method mentioned. BTW, xerexabante, just curious, is your F50 also a Q45 or one of the other trims not typically available in US (Cima, President etc?)4. I'm still dissapointed with Nissan for not using HLAs - I realize that the metal shims allow a few more HP and higher revving (there are kits available for e.g. Porsche 911 to convert newer hydraulic lifters to older shim designes to get those few extra HP, but this is a different application - Q45 is a sporty limo and I would rather give up a few HP for a convenience of not dealing with valves out of adjustments)

5. And now SURPRISE: I've just called my local Inifiniti dealer now to ask for a price of valve adjustments, and guess the answer? They don't do it!!! They don't do the engine flush either!!! The consultant said that if there is anything wrong inside the engine they just replace it (at $8000, as the warranty expired last year). But he offered me an appointment for the Factory Service (btw, the basic one, which is a mineral Quaker State oil and filter change and the ususal inspection is on special at $196.88 plus tax, regular $533 plus tax - are those great prices or what? I can do the same faster at home for about $20 in parts)

6. So I'll skip the visit to the dealer and will start thicker oil experiments. BTW, has anyone adjusted valves on those engine already?

thx

[szh]

5. And now SURPRISE: I've just called my local Inifiniti dealer now to ask for a price of valve adjustments, and guess the answer? They don't do it!!! They don't do the engine flush either!!! The consultant said that if there is anything wrong inside the engine they just replace it (at $8000, as the warranty expired last year).

You are in San Jose, CA, right? If this is Frontier Infiniti, then I am surprised! I have had them do engine flushes in the past on my old Q45. I don't know about valve adjustments, since I have not had to do that.

Who is your service consultant there? William Perry is the guy I trust over there ... very helpful, knowledgeable and willing to work with his customers (even for odd-ball requests! )

Z

[maxnix]

Better off buying the special tools and shims (better price them!) and spending the savings on oil changes and filters.

[carnut]

Yes, it is Peninsula and I did not speak with William Perry, so I've called him after seeing your post. For the valve adjustment it was the same answer (he said he has not seen a valve adjustment in 14 years he was there), but for flushes while not common they can do it. He also suggested adding oil and making sure it's at high level.

I've done more reading on the engine power flushes and opinions are mixed, so my current thinking is first a simple oil add-on flush (like MMO or Auto-Rx etc) - add/drive/drain. Or switching to synthetics as they have more cleaning power. Both could start oil leaks though...

Before I think about doing DYI valve adjustment I would need to hear from someone who has already done it on that engine - does not look trivial.

[xerexabante]

I have a shop here in Las Vegas. It has not been common for Nissan Owners to have noisy vales for me. They have always been noisier that Older Toyotas. We have been changing Nissan lifters more often. It does require a lot of labor, more for timing chain driven motors.

Yes I have an 02 q45 sport. I do have some ticking ant start up, but not as noisy as yours. I would recommend using Lucas oil addetive. I have used them alot and it does help. It an oil stabilizer helping your oil to lube better. I have used it on my my differential before, I had some howling/whinning. After i used it gone, smooth as silk, and many more applications (mine and my clients) I keep a stock in the shop. all I can say is use it and try it.

Good luck.

The contents of this message does not guaranty any fixes nor does it endorse products. I will not be responsible for any damages incured for using such products on your vehicle. The content on this message is giving advise only. It is, the vehicles owner's sole decision to use such produts. No liabilities will be held.

[carnut]

Is it Lucas Hevy Duty Oil Stabilizer or Synthetic Oil Stabilizer?

(btw, I've been driving the car daily now and the noise is no longer that bad as when I posted originally, just some ticking)

thanks

[Q45tech]

Do NOT use any oil viscosity supplement or additive, if you must use a thicker oil USE a thicker oil such as a 10w40 or a thicker upper end of grade like a Valvoline Max Life 10w30 [10w35].....10w40 [10w45].

The last thing you want to do is make a 10w30 INTO a 24w60 with Lucas or other additives and not understand what you are doing.

Things like BG MOA are just Zinc high pressure additives which don't increase viscosity.