High pitch noise in engine bay - please help

[NAM_killer]

Hey guys,

 

I've got an RZ-S that just decided this afternoon (driven this morning with no problems, but started up on the drive to move it and noticed this immediately) that it would make a high pitch noise while the engine was turned on and idling. It sounds pretty much exactly like this and I'm wondering if this is a common fault and if so, what the cause is?

 

 

Thanks in advance

[Big Mark]

Is that a bearing gone? Check A/C, water, power steering pumps etc

[kitch79]

Just my guess, because I had an something similar I could hear while stationary. Alternator. My first one that died gave off a squeal for a while before death.

If it smells odd around its location, or is REALLY hot, it’s that.

 

 

 

[NAM_killer]

Is that a bearing gone? Check A/C, water, power steering pumps etc

 

AC pulley has been removed, water pump has been replaced earlier this month before the car was sold to me and power steering seems to work ok and makes no difference to this noise. The only thing that seems to make a difference is it seems to go quieter with a few extra RPMs. Just started it up and tried a few different RPMs and it does very slightly change pitch but not much.

 

- - - Updated - - -

 

Just my guess, because I had an something similar I could hear while stationary. Alternator. My first one that died gave off a squeal for a while before death.

If it smells odd around its location, or is REALLY hot, it’s that.

 

 

/QUOTE]

 

Interesting, I'll start it up and see if it's coming from around there. I think it might be coming from around the throttle body, I'm not 100% sure... - Started it up again and it's definitely coming from somewhere around the throttle body.

Edited June 24, 2018 by NAM_killer (see edit history)

[and1c]

Remove the auxilliary belt and see if the noise is gone, if it has, as mentioned it could well be alternator or possibly idler pulley/tensioner arm.

My tensioner arm started making some odd noises, more a tapping than a squeal though.

If your AC pulley has been removed, what is in place for replacing it? or is it a shorter belt.

 

- - - Updated - - -

 

Check for vacuum leaks as well so check all vac hoses you can get to.

[NAM_killer]

Remove the auxilliary belt and see if the noise is gone, if it has, as mentioned it could well be alternator or possibly idler pulley/tensioner arm.

My tensioner arm started making some odd noises, more a tapping than a squeal though.

If your AC pulley has been removed, what is in place for replacing it? or is it a shorter belt.

 

- - - Updated - - -

 

Check for vacuum leaks as well so check all vac hoses you can get to.

 

Will do.

 

Shorter belt.

 

Do you spray carb cleaner or is there another way that you check them (if a visual inspection doesn't show anything obvious)?

[NAM_killer]

Took it out for a run down the road and I'm hitting 0.85ish BAR which seems right, it pulls the same too.

 

So it happened when I was at low revs while driving (anywhere between idle and close to idle) then fades and eventually disappears higher up the rev range while driving.

 

Now that I've taken it out I've been sitting at a petrol station for the last 5 mins and the noise is gone so it's possibly just on a cold start? I'll listen out tomorrow morning I guess...

 

Thanks for the responses and advice

Edited June 24, 2018 by NAM_killer (see edit history)

[and1c]

Remove the belt on a cold start and see what occurs.

[NAM_killer]

Crazy... This morning it didn't make the noise. Will see how it is when I start it up to go home

[NAM_killer]

Hey guys,

 

I've removed the serp belt and the noise is totally unchanged.

 

I've been listening out for the noise and when it disappears etc and have the following updates:

1. The noise seems to be throttle position dependent - if my foot is only just on the throttle or completely off the throttle, it will make the noise. Anything past "only just on the throttle" and the noise disappears. This only applies when driving. When in neutral I can't remember how it behaves but it's not the same.

2. The noise disappears completely after driving for ~10 mins or so.

 

It happens in every gear when in auto mode and tiptronic and doesn't change with speed.

 

I think that's all the info I have but if I think of anything else or notice anything else I'll make sure I note it down.

 

I've also cleaned the throttle body and it made no difference to the noise.

 

I've ordered a new throttle body gasket cause it's cheap and easy to fit, but other than that does anyone else have any ideas? I've found this, does anyone have any thoughts?

 

https://www.supraforums.com/forum/showthread.php?707873-High-pitched-whistle-noise-from-power-steering

"

It's the throttle body. My car is na-t running a FFIM so my throttle body is next to the powersteering pump. It's coming from the linkage for the butterfly. So where the cables connect to the throttle.

"

 

"

Hi mate, are you still running the factory GE TB?

 

I have read on multiple occasions about how the Q45 TB leaks around the butterfly shaft, and needs to have some remedial work done to it to avoid it leaking under boost.

"

 

The only difference is I can't hear it leaking under boost because I've got a fun air filter and exhaust