Squeeky belt on hard acceleration?

[Tokyo-Joe]

Hey all,

I have loads of niggles to work through on my new car but the biggest issue I think is a squeeky belt noise when I accelerate hard.

Do you guys have any pointers on how to identify this issue?

I have a stack of service history with the car that I'm still working through, the most relevant would be a new timing belt change 10,000 miles back.

Thanks for any help in advance :)

[Nick Graves]

Well, assuming the alternator & A/c belts are correctly tensioned and the vibration damper is intact (poke behind it with your finger) it could be a cambelt tensioner or the waterpump or alternator or lots of things there. Even a chattery clutch on the A/C compressor.

I presume the tensioners & pump were changed too?

[havoc]

I get a bit of clutch-squeal on pulling away, unless I'm very careful with the clutch - could it be that?

[Tokyo-Joe]

Hmm I guess it could be clutch slip but to me it sounds like a belt. It's only in the higher revs that it manifests itself enough that you can hear it. Very strange!

[NSXGB]

I had similar to Havoc on 'harder than normal' pull-aways. I always put it down to the clutch release bearing as I could hear a very slight rattling from the release bearing on tickover. It's definitely gone now my new clutch kit in.
If I had to describe the noise more accurately, I'd say it was like a short burst of finger nails on a blackboard...

[Tokyo-Joe]

Hmm thanks for your inputs guys, the clutch was changed for a brand new one by Honda around a month ago. Although the pedal doesn't fully pop back into the resting position (needs to be bled?) I can't identify any other clutch issues.

I think I need to collate a list of all parts that's have been replaced so I have a clearer understanding of what's still very old and likely worn.

I've applied for Kaz's health check but I'm at the back of a very long list.

[NSXGB]

Dont be too concerned by our comments, obviously it's very difficult to diagnose strange noises over the Internet. :)

[Nick Graves]

Ah - that's some more info we didn't have.

Sounds like they've not put the slave or fork back right - maybe it's the thrust bearing protesting. Why is your pedal not returning correctly?

[Tokyo-Joe]

I'm not too sure, it is consistent every pedal press, just doesn't fully return. I'm hoping a fluid bleed will help but hesitant to take it to a garage and my local specialist (kaz) has epic waiting list.

It fully engages each gear fine, drives great.

[Nick Graves]

Can't see how it will; there's a return spring to pull the pedal back to the fully up position. Which is handy, because it then allows fluid from the reservoir into the MC.

If the pedal were merely spongey, that'd be air in the system.

If your spring has sprung, it'd be like riding the clutch & it might grumble about it.

[Tokyo-Joe]

What do you think is the best way to test this?

[Kaz-kzukNA1]

Hi, Tokyo-Joe.

If I were you, I would check the easy bits first.

If your ACG and A/C belts were replaced at the time of last TB service, the tension may not be adjusted properly.
These belts require the adjustment in two stages and quite often, in order to save some time, people adjusts them just once and don’t bother about the second stage.


If they are replaced, they are V-ribbed type so they won't slip unless the tension is really low but still worth the check.

If they are not replaced and very old, then they can make noise even with slight loss of tension.



Not sure whether the clutch was replaced after or before your ownership but if it was done just a month ago, I would take it back to the place.

It could be nothing to do with the clutch service and simply a new issue emerging but worth re-visiting the place for a quick check.

I believe your NSX is early model and the clutch was replaced at the Honda garage that means it is the OEM twin disc type.

As you didn't mention any difficulties in selecting the gear, the initialise process specifically required for OEM twin disc clutch seemed to be done properly.


If there is air in the clutch hydraulic system, the noise issue would be the other way round.

You won’t be able to fully disengage the clutch and thus, you will struggle selecting the gear resulting in grinding noise and not when you are accelerating hard.


If the clutch master and/or slave cyl were replaced at the time of clutch service or recently, that’s another story.

Hope no one adjusted the master cyl push rod length unless it was really necessary.


Regards,
Kaz

[Nick Graves]

The S2000 has an automatic serpentine belt tensioner on top & mine used to squeal over 6K rpm. WD40 fixed it.

I suppose a dry belt tensioner on the NSX could cause a similar effect.

I'd forgotten that!

[Tokyo-Joe]

Thanks for the feedback guys, I shall try and get some pics of the belts.

The clutch was replaced before my ownership, the Honda garage was the other side of the country!

[Nick Graves]

Which is your side of the country?

I'd get an NSX owner to look at it - spoiling an NSX for a ha'p'orth of tar and all that...

[Tokyo-Joe]

I'm located in Hertfordsfhire Nick :)

I'm okay at some mechanical things, bolt ons etc but I'd not want to mess about with belts and tensioners etc.

[Nick Graves]

Arr, be that anywhere near Hertford?

If you want a second opinion...

[Tokyo-Joe]

Haha yes just down the road mate, i'm in Hitchin (next to Stevenage) :)

[Kaz-kzukNA1]

Hi, Tokyo-Joe.

Unlike other cars, there is no automatic tensioner on NSX.


Any belts on NSX, you have to manually adjust it and once it’s done, you have to rely on it until the next service.
This is the same for the timing belt tensioner.


Any tensioner on NSX, once it is set, it just acts as a bearing so if it fails, it will make the noise even at idle rpm.

There is no tensioner on the ACG.


As you mentioned that you don’t want to mess with the belts, following info is for the owners who may want to just check but not adjust their belt tension.

You can check the ACG and A/C belt tension based on the manual below.

10280
10281


To get some idea on how hard you need to press on the belt, put your thumb on the scale and press it until you get about 10kg.

For squeaky noise check, you don’t need to measure the tension accurately because if it is close enough, these belts won’t make noise.


If you can always recreate the same noise when you are driving, you can use the method that Nick mentioned above.
just apply small amount of silicone spray on the belt and pulley before driving to see whether the noise is coming from the belts or not.

I don’t recommend using WD40 on the belts.


I agree with you about not messing (adjusting) the belts.

Unless you have the correct tools, you may struggle to access or torque the locking nuts while the engine is in its original position.


Based on your location and the fact that something is not quite right with your CL pedal, I recommend you to contact Brian at Norton Way Honda in Letchworth.

It would be a good idea to ask them to have a look at the squeaky noise at the same time.


It may cost you but quite often, it will save some money in longer term if you act at the first sign of the issue.

Kaz

[Tokyo-Joe]

Wow thanks for the detailed information Kaz, I will try my best to follow your advice!

Edit: Excellent a trustworthy NSX garage right around the corner. Bonus!

I was uploading this short clip and noticed you can hear the belt squeel over the exhaust at low RPM, check it out:
http://www.youtube.com/watch?v=Al88Dj_EepQ

[Nick Graves]

I was out on the B655 only last week...

Actually, I was gonna just wet the belt pulley with some water & see if it squeals like a piggy; that can happen with hardened belts even in the tension is correct.

No way should timing belts be re-adjusted; it they've gone out pr the tensioner's worn, something's wrong and you're best off replacing the lot.

I'm not sure if that was belt squeal as the car pulled away; it seemed to have quite a few rpm on it & could have been the clutch grumbling. The RPM would not be rising as the load took, so the ACG etc would have 'caught up' by then.

Mine's in at Norton Way soon - I'd get them to check yours out too.

Bryan likes NSXs a lot.

[Nick Graves]

Just for the sake of clarity, on my S2000 the bearing on the auto tensioner seemed dry; there was no excessive play and it only squealed at 9K. Given its size, it must be going about 18 or 27K at that speed, so it's not surprising really.

A squirt of WD40 initially made it worse, then better, so I think I massaged in some grease and it got better after that.

Like Kaz say, only silicone spray or water on the v-belts themselves.

[Tokyo-Joe]

Thanks for your input guys.

I guess I need to save a few quid and take it to Mr Honda in Letchworth as recommended :)