Harshness at low RPM R33 - and doing cam belt

[benl1981]

Ok - since I got my R33 there has been a little harshness, you can hear noise from engine bay if you got to accelerate even softly from 1200rpm in say 2nd, 3rd or 4th.

A mechanic told me today that he would have to pull the cam belt out to have a look as it seems to be from the front of the engine or around that area.

Before this I was going to do the timing belt myself at home.

So I don't now whether I should now. Has anyone solved it by replacing a tensioner pulley etc. I guess I'd have to try and find it when I strip it down - the only thing is I'm not doing this stuff all the time so I don't know whether things look bad.

I was thinking of doing the water pump and the 2 bearings.

THe mechanic said he would replaace those if they looked suspect.

Any ideas or advice appreciated.

P.S. Engine is RB25DET

Thanks

Ben

[siksII]

the noise is probably just the engine starting to chug because u are labouring it too much, 2nd gear 1200rpm is not too bad, but 3rd and 4th!!!! too low!! you need more revs than that, just use a lower gear.

i find anything below about 1600 is too low any gear apart from 1st and maybe second, there is not enough torque that low

[benl1981]

I know what you are saying but it is a little worse than you would expect. Another friends r33 doesn't do it this bad and the mechanic thought there may be something a little wrong.

[siksII]

i wouldnt worry about it.

[benl1981]

I pulled the top timing belt cover off - the timing belt is very loose and I think the noise was it hitting the timing belt cover. So I am not really driving it till I source all the parts and either do the timing belt myself or pay someone to do it.

The car is at 97k so it was time to do it anyway

[siksII]

it may not have been installed properly, there is a particular way of tensioning it when installed... get it checked out i guess

[GTRgeoff]

Ben, I've experienced a similar problem that I discovered to be the woodruff key failing, allowing the harmonic balancer to slop about damaging the keyway in the process. It was a harshness between 2500 and 3000 that could be felt through the gearshift. Fortunately nothing some loctite bearing mount couldn't fix. Depending on the state of balance of your engine it could reveal at the much lower rpm.

Certainly keep this in mind and seriously consider replacing the bearings at the same time as the cam belt. There is an extensive thread on doing this and sourcing the bearings for about 120.

[benl1981]

Thanks guys - I found a post with the bearings costing $104 for both - they are not NSK but a japanese brand from a place Mekong spares in Sydney. I assume they are the pulley aswell i.e. bearing inside.

Do people replace the spring aswell? I'm thinking that could be part of the problem? It has a bit of surface oxidation/discolouration.

Geoff - DId you get a new key, or is thekey part of thhe crank?

What I plan to do is...

Timing belt

the 2 pullley bearings

Check what you said Geoff about the keyway etc

Water pump ($130 from nissan)

I don't think I will do any of the seals - they sound a bit of a hassle.

Cheers

[TurboX]

I bought a GATES timing belt at Autosalon on weekend for $100 from HP inaBox.

Seemed like good value, supposed to be 3x stronger.

I think Nissan want similar money for a product thats not as good.

[GTRgeoff]

Do people replace the spring aswell?  I'm thinking that could be part of the problem?  It has a bit of surface oxidation/discolouration.

Geoff - DId you get a new key, or is thekey part of thhe crank?

I don't think I will do any of the seals - they sound a bit of a hassle.

No need to replace the spring it is only tension for fitting the cam belt. The real tension is applied be a hex key and lock nut.

Got a new key from nissan for about $5 but the locktite was needed due to damage to the crank keyway.

Do the seals as they are pretty easy once the rest is out but it all comes out again if a seal goes. Just get VL turbo front seals from Repco for about $15 each.

[benl1981]

Thanks for that. So there is no real self adjusting of belt tension at all ok. I though the spring might do this.

Anyway - how hard is it to do the crank seal? Or are you talking about just the cam seals?

Doesn't seem like too hard a job..I just don't want to get it wrong!

[GTRgeoff]

No there is no self adjustment, but beware of the tension. Too loose or tight can cause problems, but your mechanic should be OK on this.

The crank seal is not too hard but will get destroyed removing as you need to go past it to pull it out. Gentle installation is the key with a seal setting tool or gentle pressure with a brass drift working around the edges. It should just press in without need to hammer.

The seals get hard with age and can fail suddenly allowing oil past so it is worth doing.

[benl1981]

What did you do on yours Geoff - all the seals?