Noisy Timing Belt After Change

[cefiro]

Hey guys I just finished doing my 100k service and it was a challenging task, I put everything back together and turn it on and its making a funny noise like a belt is loose, so checked all tension in the drive belts all seem fine not slipping, ended up taking the front cover off and seems that the noise is coming from the new timing belt. Its very annoying, anyone have any suggestions in what to do, the belt is not loose, but i dont think its over tight either, I also upgraded my cam gears to adj type????

Cheers

[The Dan]

The new belt will need time to bed into the new gear. It is possible that the belt is slightly too tight but give it a month or so and it should quieten down.

[GTRsean]

If it's gates belt they tend to be a little noisier.

[omy-33]

is it like a whine-ing noise til the engine gets hot, because mine does the same thing.

then my waterpump shit it self because of the tension from the new belt, so keep an eye on your water.

[LotusGTR]

Yeah, mine does it too until it's warm. Mechanic tensioned slackened and tensioned again. didn't shift it. It's a low level whining that seems to slowly disappear as the engine gets temps. It's almost like a cistern filling. I know that sounds wierd but that describes it for me. p.s. my belt is new and I've got adj cam gears.

[cefiro]

It does it warm or cold, its a genuine nissan one too.

[boostn0199]

yeah i just recently put a gates belt in and i get da noise aswel until the car is warmed up. hrmmm not sure if yours does it all the time, just wait abit and see if goes away

[The Dan]

Gates makes the belts for Nissan and also they do the Racing version. The racing version is more likely to be noisy than the Nissan belt. It all has to do with harmonic of the belt. If you have the genuine belt and an aftermarket gear, the gear could be slightly out of round or the material that is used for the gear is coarse. Don't stress about the noise for the time being. The belt will not break.

On that note, I hope they changed the idler bolt (M10 x 70mm) as this little bastard has a habit of breaking when the belt has been changed.

[The Dan]

is it like a whine-ing noise til the engine gets hot, because mine does the same thing.

then my waterpump shit it self because of the tension from the new belt, so keep an eye on your water.

That's a poor installation by whoever fitted the Alt belt. Too much tension or starting the car before there is water in the system fully will cause the pump to go awol.

Best rule of thumb to use is when the belt is tensioned, you should be able to turn the belt 90 degrees on it's side on the longest side of the belt.

So if you are doing the alt belt, anywhere on the belt between the alt pulley and the water pump pulley, grab the belt and twist it sideways. It should turn 90 degrees but no more than that. If it's difficult to get 90 degrees then it's over tight, if it goes past 90 then it's too loose.

[cefiro]

Thanks for the reply's guys I think I will see how i go and if there is no change I will have to re tension it or take it to a mechanic and as their opinion and have them do it or depending how much it annoys me then do it on the next few days and add to the mountainous cuts I have on my hands. Such a pain of a job to do the first time but now could do it with some confidence.

Cheers

[omy-33]

That's a poor installation by whoever fitted the Alt belt. Too much tension or starting the car before there is water in the system fully will cause the pump to go awol.

depends on how worn the pump was 2, it did look pretty beat up when i saw it on the floor while the new 1 was getting put in.

[tacker]

sounds as if its a fraction to tight mine did the same thing until i let a little tension off.

[murrayis]

Take a listen to this video, this is mine today with the belt too tight on my first startup.

If yours sound miliar then that your problem

[dangerman4]

is that a blue gates belt there?

the blue stuff on the back of the belt makes that noise when it rubs on the idlers.

after 1000 kays have a look at the idlers they will be covered in lumps of blue gunk.

i removed the belt and the brand new idlers gave them a clean with a wire wheel and installed a genuine nissan belt prob fixed.

no more noise.

it had nothing to do with the belt tension,

just a common flaw with the blue gates belts.

[GTRsean]

Too tight. I've had that exact problem before, same noise. Tension is too tight.

Had a HKS belt and it made that noise. After a while it flogged out the idler bearings (read made em noisy at startup) because they got so hot from high belt tension. The stuff on the back of the belt had melted onto the bearing surfaces as well.

Mechanic did the tension wrong, is all I can say, on mine. I did mine myself by the book, turn crank a couple of rotations and let the tensioner spring do the work, then tightened up the nut while holding the allen key in the same spot.

[cefiro]

looks like wil be pulling everthing out again, fark. So to get the tension right, slacken off the bolt and allow the spring to take the tension from the belt then rotate engine a few times and just use hex key to keep tension in belt then tighten nut. Is that the technique???? hope I can get the harmonic balancer bolt off again, thats a bitch to do.

[murrayis]

yea unless u get one line mine that doesn't have a spring on it

[femno]

I have a gates racing belt and its quiet as a mouse and its not loose.

y'all have ur belts too tight.

[The Dan]

looks like wil be pulling everthing out again, fark. So to get the tension right, slacken off the bolt and allow the spring to take the tension from the belt then rotate engine a few times and just use hex key to keep tension in belt then tighten nut. Is that the technique???? hope I can get the harmonic balancer bolt off again, thats a bitch to do.

If you are local to Brisbane you can borrow the tool I have for doing it. It will undo and do up the bolt with very little effort.

The correct way to tension the belt (if you don't have the weight to get exact load) is to loosen the tensioner so that the bearing can swivel freely. Make sure the belt is on and the marks are lined up. Turn the crank around slowly in a clockwise rotation. You will notice at certain intervals it will become difficult to turn as the pistons try to make compression (obviously the spark plugs have to be in for this). When it is most difficult to turn you will notice the tensioner bearing move against the slack in the belt. Hold the tension on the engine (ratchet or spanner) and tighten the nut for the tensioner with a 14mm spanner. This should give you the correct tension.

[cefiro]

cheers mate will be doing it today, ahhh I did crank it over a few times by hand last time but I had moved the idler pulley away with it tightened up not allowing the spring to work, well I spose its a lesson learned should only take a few hours to fix up but thats all things going well, but this never seems to be the case. Ha

Cheers for the offer 3lit3_32 thats very generous of you, I am in sydney though last time I had to get a mobile mechanic to help so let hope I get it off on my own accord.

Will let you know how I go.

Edited October 6, 2008 by cefiro