Guys,

 

my engine has developed a new noise, and i cant tell what it is or where it is coming from. It started off as a very intermittant noise, but is becoming more and more frequent.

 

Ive taken a few videos, one from inside the car, and one searching around the engine bay. The noise does not get louder when put under load but the speed of the rattle increases with engine speed.

 

Im pretty sure it coming from the front half of the engine and is louder on the drivers side. Have a listen and tell me what you think

 

 

Edited November 15, 200817 yr by nickz32
because i should read stuff before i post it

dose it sort of go just after a small rev a very slight rev or is it there all the time?

when you get above 3 - 3.5k rpm you cant really hear it because the overall noise of the engine takes over, but it is still there. It seems to be at its most audbile at tickover and between 2k and 3k rpm

maybe you need some shells? im sure a good machanic can just tell you if this is the case.and it will save your engine if it is and you can do with engine in situe.

sounds very much like the issue i had this turned out to be the water pump bearing rattleing and eventually dieing did not find this out until all the water had dropped on the floor

saved my engine though.

 

Take to a good mechanic should be able to find the source with any luck for you exactly.

if you put your hand on the cambelt covers can you feel any virbration! check the belt tension.

maybe you need some shells? im sure a good machanic can just tell you if this is the case.and it will save your engine if it is and you can do with engine in situe.

 

im convinced its not big end shells. My previous zed blew its big ends, and the noise is no where near as metallic or invasive as big end rattle

It sounds to me like it's not the engine it's self, but something being driven by the engine, perhaps alternator bearings or something similar... Try turning on your air con on, see if there is a difference, and turn on everything electrical you can, to put a load on the alternator with someone listening, see if that makes any difference, and try taking off the cam belt covers and seeing if it's coming from there mate..... HTH.

Do you have your AC on all the time Nick?

Did think about that mate, but no the air con is off most of the time, and its off when i took the vids

Im thinking either alternator bearings, viscous fan clutch or maybe cambelt tensioner

It sounds like the AC pully. Mine makes a noise when I turn it on. So, with that in mind, I'd suggest it would be a bearing of sorts. Poss idler pully or water pump?

Nick that is a very recognisable noise, given that the microphone has picked up a lot of noise that is normal and muddying the waters a bit it still is clearly a belt pulley and the most likely is the top cambelt one, Id guess the noise is worse when the engine cold

 

The adjuster pulley on the aircon and the alternator can also cause noise but that cetainly is a cam belt pully, give me a couple of hours and will post a couple of pictures to show you what the problem is, as I dealt with the very same fault earlier this week.

 

The fix is simple and not particularly expensive either.

 

 

Jeff TT

Cheers jeff. I look forward to seeing the pics

I had a very similar noise on mine Nick when I first got the car,was worse when cold,that was the top idler pulley as Jeff has mentioned.

Take a look at the the photos, the engine was noisy in the front cam belt area, the top cam belt pulley bearing was the cause of the noise, unfortunately before we had time to take a look the noise got worse until it was so bad the owner decided to not use it and waited until the AA could transport it.

 

The right hand cambelt cover was loosened to reveal a very slack belt,

subsequent strip down and the collapsed bearing was there to see.

Replacing the offending item a new cambelt, inlet pipes thermostat etc sorted it quick time.

 

The final photo shows the pulley and the bearing carrier minus a load of ball bearings some of which were embeded in the cambelt and some trapped in the covers.

 

Not saying all noisy pulleys will end this way, but better to be safe than sorry.

 

Jeff TT

 

[ATTACH]45002[/ATTACH]

 

[ATTACH]45003[/ATTACH]

 

[ATTACH]45004[/ATTACH]

Quite often you see cheap cam belts jobs where they do just the minimum like a belt and may be the tensioner with out doing the water pump and idler bearings. A few dollars saved (or pounds in your case) ends up costing a lot more later on.

 

I did the same thing when I did my car and didn't replace the water pump (against the advice of my mechanic):rolleyes: only to have to do it a few thousand kilometres later.

 

May be a similar thing

Another cause of pulley failure is an overtight cam belt, the adjuster is self tightening but the set position on the block is adjustable and have seen quite a few wrongly set on the block causing an overtight belt even with the adjuster not extended at all, at the end of the day the pulley is mechanical and can potentially fail so inspection is the key, changing belts without even checking them is more the problem, ensuring the workshop who changes your belt is fully experienced in Zs is the most important.

 

Jeff TT

My aircon belt tensioner bearing went and it sounded very much like yours , that was an easy repair , hope yours isn,t anything too serious . :hyper:

hey think mine might have this problem too although it is intermitant .... cant wait for the pics to give me an idea what to do...:)

seen the pics o oh...( gonna have a look trouble is mine is at the bodyshop and gotta drive it back...now im scared