Squealing Noise When Hitting 4,500rpm

[Mr-Toy33]

When I hit 4,500RPM (which is probably when I'm hitting full boost) in the gts-t R33 skyline, it starts to make a squeeling noise and does it in all gears when hitting 4,500RPM. Anything under 4,500RPM, it doesn't make that noise.

It's pretty much a stock standard skyline (apart from the exhaust from the cat back, turbo timer & boost guage). It's done 120,000k's and I just did a oil filter & oil change to it on the wknd plus radiator fluid but was making this noise before I did the service.

Just wondering as to what it might actually be?

Someone has said it could be one of the belts that are making that noise.

Another person has said it's the bearings in the turbo (dont know about that one).

Any ideas or anyone know anythin from this happening to them?

It's a 1993 model.

Thanks!

Edited August 30, 2005 by r33skyliner

[Mr-Toy33]

Deleted reply.

Edited August 30, 2005 by r33skyliner

[Oosh]

Sounds like belts, free rev and bounce it up to 4,500 RPM (don't hold it up there), and see it makes the noise.

It's highly unlikely it's your turbo, turbine speed is dependant on engine load NOT RPM, so being out of gear will take the turbo out of the equation.

If it does then spray some WD40/RP7 on the belt pulleys, do it one belt at a time, if the noise goes away you know which belt it is. Then proceed to tighten that belt.

[gtrken]

Loose turbo to manifold or blown gasket.

When it hits full boost it sounds like a whistle/screeching sound as the air is being forced out through the small gap.

Cheers

Ken

[soon2b33]

oh no.. thats the exact sound ive heard, very very faint whistle at 4500,5000rpm

i was hoping it was not anything to do with the turbo tho

[Mr-Toy33]

I hit about 5,500RPM last night on cold start when I first started the car and their was no squealing noise in first gear. Hit 2nd gear and still no squealing noise. I then pulled over for about 2mins and then took off and hit 5,000RPM and then it squealed.

So what could this possibly be then? A belt or the turbo or possibly the manifold?

If it is the manifold and a new one is needed? How much am I looking at for one?

[grigor]

Read your PM's

[Mr-Toy33]

I've read the PM's but after diagnoising the problem a bit last night, thought people may be able to further help as to what it could be.

Also to note. When the car was idling last night at lights and in the drive way. The oil guage was sitting between the bottom line and the quater line. When driving, it would then rise up a bit just past the quater line but doesn't go past the half way line.

Edited August 31, 2005 by r33skyliner

[Oosh]

I hit about 5,500RPM last night on cold start when I first started the car and their was no squealing noise in first gear.  Hit 2nd gear and still no squealing noise.  I then pulled over for about 2mins and then took off and hit 5,000RPM and then it squealed.

So what could this possibly be then?  A belt or the turbo or possibly the manifold?

If it is the manifold and a new one is needed?  How much am I looking at for one?

<{POST_SNAPBACK}>

You really shouldn't be taking it above 2500/3000 until it hits operating temp you know, be nice to your car until it's warmed up, then punish it like it deserves!

Did you try it free revving? Make sure it's warmed up, do it when you get home from work or whatever, just AFTER a drive when everything is warm.

If you can get someone else to sit in the car and rev it, then pop the bonnet, and that way if it makes the noise you'll hear it better and might get an idea where it's coming from.

[Oosh]

I've read the PM's but after diagnoising the problem a bit last night, thought people may be able to further help as to what it could be.

Also to note.  When the car was idling last night at lights and in the drive way.  The oil guage was sitting between the bottom line and the quater line.  When driving, it would then rise up a bit just past the quater line but doesn't go past the half way line.

<{POST_SNAPBACK}>

That's pretty low, before you do anything else check your oil level, and what type and viscousity oil are you using?

Just as a comparision, when starting cold my gauge sits at half-way, or 4 as it's marked on the gauge, once warm the car idles at one quarter (2), and when under load climbs back up to half-way (4) and a bit more when going hard (say ~5).

[Mr-Toy33]

I just completed a oil filter change and oil change to it on Saturday just gone. Running the Motul 4100 turbocharged oil in it now.

There is no oil leaks though.

[Oosh]

That's a 10w40 yeah? You should be getting better oil pressure than that I'd think, double check your oil level (HOT), just cause it isn't leaking doesn't mean it's not burning it or there wasn't enough in there in the first place.

[B0oStEr]

The factory oil pressure gauges often have a problem with the sender and read low or erratic.

Get someone to check the oil pressure with an accurate screw in gauge.

[Mr-Toy33]

Sounds like this is just goin to be a costly issue to have it looked at.

Sounds like I rather just give the machanics the go ahead to fix whatever it is. Would cost the same to have it fixed then to have someone look at it.

But, knowing 99% of the machanics these days. They'll say its one thing just to get the extra few $$'s out of you when really it was something little and simple that would of cost me alot less to have fixed.

[Oosh]

You need to do what you're most comfortable with, if you've got the time and can keep coming back here for free non-professional help, and the confidence in your own abilities then great.

If you just want it working and are prepared to pay what you will for it then take it to a mech. Have a poke around Qld sub-forum and I'm sure you'll get on to a reputable place that know their way around RB's.

[Mr-Toy33]

Ok. Had someone professionally look at it last night and they've determined for me that it is actually the turbo. It's the propellar fans (i think thats what they are called) inside the turbo which are actually hitting up against the wall.

This now explains the noise as well as the great lost of power that it once had.

So, I'm up for a rebuild of the turbo.

All up, the rebuild of the turbo is going to cost me a bit under $2g which they'll high flow the turbo for me giving me more power.

So, the car will be booked in to have all this done within the next few weeks and I should be back on the road after thats all done.

I can still drive the car, but highly recommended not to hit high boost as it'll just cause more problems

[cme33]

High flowing your turbo will be good, but i suggest you replace it and get a ball bearing turbo, you'll save a bit of $$$ and you can get bolt on turbos for your manifold. Try horspowerinabox.com

[Jago]

newho, back to the original noise, even though it has been diagnosed, that kinda noise is generally an exhaust leak of some kind, another hint is that it only happens when you come onto boost or are at full bost

[srbskyline]

nothing to do with the turbo its a leaking exhaust and/or a cracked exhaust manifold . had same problem

[Mr-Toy33]

nothing to do with the turbo its a leaking exhaust and/or a cracked exhaust manifold . had same problem

<{POST_SNAPBACK}>

It's been determined that it's actually the turbo by 3 mechanic's now.

There inpropella fan is rubbing up against the housing. I'm able to pull that inpropella fan back and forward about 1mil, maybe less which is not good at all. All 3 of stated that it would be ok if you can go side to side about 1mil or less, but not back and forward.

It is a ballbearing turbo.

Car has been booked in with Hardcore Racing to have the turbo rebuilt and high flowed.