Hello all, I'm a new G35 owner coming from an SC400. Glad to be here - but with every new used car, there's always the problems that need to be sorted left over from the last owner it seems. I'm here to hopefully get a little input on the main one for this 2003 G35 coupe I've got:

And this issue is a curious one After pretty much beating the internet because I've searched so much... all I have EVER found on squeaky pulleys and belts is that it supposedly happens when cold and then stops when hot.

Except of course, if it's my car... because in my case it's exactly the opposite.

My G35 (2003) is quiet and buttery when first started both at low and high rpms, but once the engine gets up to any sort of normal operating temp (generally in 3 minutes) and a normal driving rpm (2000-3000 or higher) I start to get an INSANELY LOUD SCREAMING SCREECH/SQUEAL. I'm not sure I can properly convey just how loud this sound is with words - I mean, it's so loud you can hear it blocks away. It literally hurts my ears (bad) if I'm standing beside the car and someone revs the engine. Oh, to add to the confusion, as I'd just stated about once everything is all heated up and the sound is at it's worst... if I stop and let the engine go back down to idle speed there is almost no sound of this at all again! Just the random fairly quiet/light chirp of that sound. A harbinger if you will of the next press on the accelerator. As soon as torque/throttle is applied again - whoa baby does it get LOUD!

So again to note, the sound is tied in volume and *when* it happens to the RPM of the engine and apparently the temperature of the guilty component.
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Cold Engine with any RPM: low sound to maybe not even the sound at all
Hot Engine with Low/idle RPM: low sound to maybe not even the sound at all
Hot Engine & High RPM: lots of loud squeaking.

After doing my best to get a feel for where it might be coming from by listening, it appears to be on the front passengers side area of the engine around that end's tensioner pulley or steering pump (That's the one farthest out on the passenger side right..the steering pump right?)

I'm not familiar enough with this car (only owned it for 3 days at this point) to know if I can take all the belts off and start the engine without destroying it. Can I do that? If so, I can start the engine and determine immediately if it's a pulley because if there are no belts and no sound then tada of course it is.

I've only driven the car a total 7 miles since I bought it trying to be err on the extremely safe side. It HAS to be fixed, and I'm trying my best to figure it out - so your input is MASSIVELY appreciated.

 

First, check the belts and make sure they're good (with no cracks). If they are, then one of the belts is probably too loose or tightened too much. Can't remember which it is... But I know the belts will expand/contract based on temperature. Should be in the FSM.

 

Thank you for chiming in

Looking at the belts - I have 4 because of the supercharger - the grooves sides show no signs of cracks that I can see. And the tops are smooth....I don't know what a glazed belt really looks like but I've heard that term come up during my searches.

The thing I want to ask you about though is this: while doing all my searching, and as indicated above in my OP - this same response has been given to myriad other's asking about belt and pulley squeaks. But that was always for when it was squeaky during start when everything was cold - and that it naturally went away once those people's cars warmed up. But never for a situation like mine which is the exact opposite. You still believe the tension applies correct?

As for that, where are the tensioner adjustment locations - and are they all accessible from a standing position in front of the car? Or will I have to jack the car up and get under it for them?

Again, thanks for lending a hand with info here - I appreciate it!

 

It's definitely easier to jack it up and get to them from underneath, by where the radiator is. You'll have to take the bottom front cover off to get to them. You may be able to do it standing overhead...Probably depends on what tools you have.

In the FSM, it says you have to tighten new belts more than used belts also. One more thing to consider.

 

How can I get a copy of the Shop Manuals?

 

Upon closer inspection of the two standard Infiniti drive belts, they are cracked *slightly* on the ribs side.... But more troublingly - they are literally covered in grease on the ribbed side! (tops *seem* to be grease free... but who knows really since it's so smooth, maybe the grease is just cooked in)

How on earth did that happen? And could this be the reason why I don't have squealing / squeaking when cold, and then do when hot? I dislike speculating, so I shouldn't. The sound still reminds me of when my old skateboard bearings in the wheels would get dry (no internal lube) though.... arrrrg. Just want to KNOW what this is so I can fix it.

Back to the grease situation. Has anyone else has their belts become just inundated with grease? If so, what is the source of the grease?

I'm getting the feeling that maybe the shop who installed the supercharger put extra grease on the pulleys for that system maybe? And in the natural process of it spinning out it's gotten all over the other belts? It's all speculation at this point from my end but there's a lot of grease from somewhere.

Regardless, I'm buying all new belts. What are they called / are their parts number for a 2003 G35 coupe. Will that be in the FSM somewhere?

And have suggestions for the process of cleaning grease out of the grooves on all these pulleys? Solvents, brushes etc?

 

Slight cracking isn't nothing to worry about. They will usually still last a while even after that starts.

They aren't supposed to have grease on them though. That's probably your problem right there.

 

I went out (just a moment ago) after work and grabbed both the belts from my local Nissan dealership. Came to 41 bucks after tax... average price I guess overall. I'm not certain when I have the time to do the install this week, luckily I kept my SC400 as a daily driver so it's not a dire 'must get it done' situation - but still, I'll be doing it the first free chance I get I'm sure.

At that point, if it still screeches - it's obviously a pulley - but at least I'll have new belts on.

The last question now is - can I turn the motor over without having either of these belts on. I'll need to in order to effectively clean the main crank pulleys (the double wide set) of all the grease they might have on them. The other pulleys I should be able to clean rather easily as they *should* spin freely. And there again, if one of them doesn't - I might find the culprit in that whole process - again ending up with new belts anyway

 

You'll have access to the entire pulley to clean it without turning the motor over. If you must crank the engine, it'll crank without the belts. BTW, now is the best time to replace the pulleys.