Bearings bearings bearings

[David Kemps]

hey guys,

after I start my gts25t from cold it makes a kindof bearing noise whine, (I think) it's not too bad but noticeable. After 5 mins it goes away.

The noise changes with the revs.

I thought it was the gearbox, but it still does it when I push the clutch in.

Also thought it might be the water pump/alternator/a/c/power steering but don't think its that cause it sounds like its coming from the back of the engine.

Any ideas what it could be?

The engine has done 130,000kms, seems in good condition apart from that.

It's standard and was automatic until last year so don't think it has been thrashed.

The fuel pump, afm and water pump have been replaced. (previous owner said)

Can I put a metal rod onto the engine somewhere to "Listen" to the noise to figure out which bearings it could be? Whereabouts would i put it to listen to it?

Is it hard to replace bearings inside the engine? Do they cost a lot?

I'm mechanically minded, done gearbox changes etc but haven't opened up the engine before.

Also do 25t gearboxes cost much for bearings? Can you replace them yourself?

I'm worried if I leave it, it might stuff up the whole engine.

Dave

[gts4diehard]

hi, check the following.

press clutch pedal in about 10mm, if sound goes away it is the thrust bearing that presses against the clutch fingers.

press clutch all the way in, if noise goes away it is likely to be the layshaft bearing( at front of the gearbox)

other bearing noises are as you listed and also the cambelt tensioner bearings. can listen to cambelt cover with a screwdriver handle to your ear - assuming of course you dont have long hair etc that will get caught in fan...

I replaced mine about 140-150000kms on my RB20det, one was fine, the other sounded raspy and feels rough when you spin by hand - i replaced both. If you can do it yourself you should be able to get the bearings for under $200 pair.

Stephen

[GTRgeoff]

Also, if you used a new cam belt it could be just a little tight and causes a whining noise that could be similar to what you have. Overtightened they can cause the idler pully bolt to snap causing piston and valvetrain damage.

[David Kemps]

Ok thanks guys, that info has helped heaps!

This is what I've figured out:

-the noise is coming from the front of the engine, was hard to figure out before.

-My a/c is not working so could be the a/c compressor.

-My cam belt was changed last year according to owner, it has marks on the cam angle sensor so I'm sure he was telling the truth.

Action:

-Gonna undo belts to a/c, power steering/alternator and start up and see if the noise was one of those.

-If not it must be the cam belt bearings.

Is changing the cam belt bearings very hard? Where do I get them from? Expensive?

I'm hoping it's the a/c compressor, cause will be easy to fix, there's a few for sale here in NZ.

Gonna check this weekend, do NOT want the engine breaking from the cam belt stuffing up.

Dave

[GTRgeoff]

This might help but doesn't give an indication of correct tension.