Strange Sucking Noise

[Deziner]

Today my R33 GTR started making a weird sucking noise.

It has pod filters, but the sucking is not coming from them. The noise happens both while stationary (idleling) and also when driving.

It sounds like it is coming from the front of the engine bay but cant pin point it.

It dosnt get louder or quieter depending on speed/RPM's etc. is always sounds the same.

It sounds like a valve opening/closing and sucking air.

I have not done any work on the car since buying it so it has started out of the blue.

Any thoughts?

[Deziner]

Just had a bit more of a look around.

I think it is coming from under the cover where the cam gears are. You can feel it kind of knock when you put your hand on it when it makes the noise.

Any ideas?

[Deziner]

Some more info that may help.

One of the belts was making a squeale on startup when cold, but would go away within 1 minute.

The morning the noise started the car backfired once but not after that.

Also the car still runs fine, both in gear and at idle, no hesitation no other starnge noises.

Timing belt was done not that long ago, maybe 8 months ago I believe.

Have searched this forum as well as other and Google and can not find anything similar.

[Deziner]

Started the car for the first time since the noise started, a couple things I noted.

The squeal that used to be there is still there but for a lot less longer.

Also, the noise didnt start immediately, it took about a minute or 2 of the engine idleing for it to start.

[116.hks]

Were the tensioner and idler bearings replaced when the timing belt was?

Your other squeal could be a strecthed belt, either alternator, a/c or power steering. If the were replaced at the same time as the timing belt they could have strecthed a couple of mm's.

[Deziner]

Were the tensioner and idler bearings replaced when the timing belt was?

Your other squeal could be a strecthed belt, either alternator, a/c or power steering. If the were replaced at the same time as the timing belt they could have strecthed a couple of mm's.

Not sure if any of the other parts were replaced when the timing belt was.

Would any of these lead to this sucking noise?

When I say sucking, that is what it sounds like, not sure if it is actually something sucking in air.

[paulR32gtr]

Just had a bit more of a look around.

I think it is coming from under the cover where the cam gears are. You can feel it kind of knock when you put your hand on it when it makes the noise.

Any ideas?

I would be very wary of starting the engine if there is knock coming from under there

It's a bit painful but are you able to take the cam gear cover off and make sure the timing belt is looking ok? Very hard to diagnose over the internet but maybe a fraying timing belt whipping around might cause something like the sound you are describing.

I would be checking all the critical things first before proceeding.

[Deziner]

I would be very wary of starting the engine if there is knock coming from under there

It's a bit painful but are you able to take the cam gear cover off and make sure the timing belt is looking ok? Very hard to diagnose over the internet but maybe a fraying timing belt whipping around might cause something like the sound you are describing.

I would be checking all the critical things first before proceeding.

Yeah, I am very wary!!

I have not looked at taking the cover off and what is involved (i.e. do I need to take the radiator fan out etc.), not sure how hard or what tools are required.

I am pretty sure it is something to do with one of the belts. Like I said, I started last night because I wanted to see if it still made the squeal and it did but only for a second. Before it would squeal for a minute or so until it warmed up.

If the timing belt slipped, even a notch it would run the same correct? it still runs like it always has, just this noise!!

[116.hks]

The timing belt wont squeal. The squealling noise is 1 of the other belts. As ol mate said, take the top timing cover off and inspect the belt. If you can feel a knock from their, it's got to be inside. If you are not capable of doing it, i'd get a mechanic to do it before something goes really bad.

[Deziner]

Booked the car in for next week at one of the SAUWA sponsors.

They are only a couple of Km's down the road from me so hopefully I make it!

[Deziner]

Well it turns out the car never had it's 100,000K service.

Workshop replaced the idler bearing (which was the culprit for the noise and mechanic said was missing half the ball bearing and he was surpised it was still spinning, also replcaed the tensioner, timing belt.

Radiator was also flushed and pressure tested, turned out to be 70% blocked.

While in the shop also had the boost restrictor removed and timing adjusted to suit BP Ultimate. Also had a service, all oils etc.

First Dyno result they did saw it making 230hp at all four wheels, end result was 288hp at all four wheels.

The car is stock except the pod filters and the removal of the boost restrictor.

They said it would have made 300hp at all fours but the stock fuel pump started to struggle.

[Deziner]

Oh and they replcsed the old water pump too.

[Deziner]

Wow, picked the car up today and it feels great. Got it done at Autoworx, good job, will definately be going back there.

Can feel the difference going from 230hp tp 288hp.

[Mayuri Krab]

How much did it cost you if you don't mind me asking?

I think I have similar squealing issues at the moment.

[Deziner]

All up it was $1470.

[Deziner]

Sorry, that $1470 was for everything, not just the idler bearing. so it included:

Timing belt, idler bearing, tensioner, water pump.

Also included radiator flush, service (oils, oil filter) etc., removal of boost restrictor and adjustment of timing to suit BP Ultimate.

Included a couple Dyno runs as well.

Pretty good I think. Very happy with the result. Next will be upgraded turbos and exhaust system.