Hey guys, just wondering if someone could point me in the right direction/help me troubleshoot my problem.

What's happening is I'm getting a strange rattle sound when the car accelerates/revs. It doesn't do it all the time, but just now and then, and only up to about 2.5-3k rpm. Sometimes (maybe 1 in 3 starts) it will make the sound on ignition as well. Anyways, I am a bit unsure what may be causing this sound. My only thought might be a clogged up injector?

I have removed the engine cover to try and pinpoint the sound but am still not 100% certain, but it does sound like it's coming from the rear of the engine bay near the firewall. Now I do know I have a small leak from the power steering, but I doubt this problem is anything to do with it, but thought I would mention this just in case.

Also, today I have changed the oil and filter in some hope that it would magically disappear (although it needed to be done anyway :P) and at first there was no sound, but after 5 minutes of driving I heard it again, and by the time I got home it had stopped again...

Thanks for any advice/help in advance,
Matt.

Sounds to me like it'd be the Timing belt tensioner...

Sounds like the guts of the cat converter are broken given that the sound is coming from the rear of the engine bay? Usually you would have some other sympoms with this though, but not always. Get underneath and give it a bit of a tap to see if the honeycomb is broken.
Could also be something as simple as a loose bolt.

Sounds to me like it'd be the Timing belt tensioner...
Ahh, ok thanks mate, how would I go about checking this?


Sounds like the guts of the cat converter are broken given that the sound is coming from the rear of the engine bay? Usually you would have some other sympoms with this though, but not always. Get underneath and give it a bit of a tap to see if the honeycomb is broken.
Could also be something as simple as a loose bolt.

I did check that out today while the car was up on the ramps, and the cat seemed fine to me but thanks for the input anyway mate :) I will also have a feel around for loose bolts etc as well.

Check the heat shield on the rear exhaust for looseness, might be as simple as that.



+++RIP JPS +++

Check the heat shield on the rear exhaust for looseness, might be as simple as that.

Cheers, had a look and it's on there tight as ever lol. Don't reckon that's the problem, but it is still a possibility. If I don't get much else, I will take off the heat shied and go for a drive to see if it still makes the sounds. Cos actually when I first heard the sound, my first thought was a heat shield or something :P

Sounds to me like it'd be the Timing belt tensioner...

Hmmm I've been reading through old threads about this thisarvo and I am not sure whether it would be the tensioner or not. I have this issue even when the car is at running temperature, and it only occurs when accelerating, revving. From what I could tell, the sound due to the tensioner was mainly on startup for 30 seconds or so when the car is cold, while the belt gains tension. Now I may be completely wrong here, but that's my view on from what I have read.

I went for a short drive before and paid more attention to the rev range where it occurs, and it actually appears to happen up to 3-3.5k revs, not 2-2.5k like I originally stated. Hmmmm...

What do people think of my fuel injector assumption by the way? Completely off or...?

Cheers guys.

A good while back, I think there was discussion of a mystery noise which came down to a divider in the exhaust where front and rear bank engine pipes merged into the "Y"....... a poor weld inetrnally let a piece of metal vibrate or even come loose and rattle (it was intended to isolate the gas flow from each engine bank). Could that be the culprit?

A good while back, I think there was discussion of a mystery noise which came down to a divider in the exhaust where front and rear bank engine pipes merged into the "Y"....... a poor weld inetrnally let a piece of metal vibrate or even come loose and rattle (it was intended to isolate the gas flow from each engine bank). Could that be the culprit?

Hmmm, definately sounds plausible! I will try to investigate this on the weekend, or possibly tomorrow arvo. It is a metallic sorta sound, and could possibly be this. Most of the Exhauset (Cat-Back) is fairly new, but the "Y" piece you speak of did look a lot older than the rest of the system. I will take a photo tomorrow just to make sure we are both talking about the same place. Cheers! :)

Thank you Elwyn,

This is a very common issue, the point where the 2 pipes merge have a flow plate, these are spot welded on and with all the carbon, heating and cooling the plate goes brittle and then eventually snaps off. The issue is it can go back to the Cat and will rattle in the rev range yo have described

You can get it removed but it is best off being there, I have on occasioin opened up the pipe, repaired the pipe and welded back up when I can not get another engine pipe

Thank you Elwyn,

This is a very common issue, the point where the 2 pipes merge have a flow plate, these are spot welded on and with all the carbon, heating and cooling the plate goes brittle and then eventually snaps off. The issue is it can go back to the Cat and will rattle in the rev range yo have described

You can get it removed but it is best off being there, I have on occasioin opened up the pipe, repaired the pipe and welded back up when I can not get another engine pipe

Cheers for that Mal. So what you are saying, If this is my issue, there's probably not any simple DIY way of fixing it unless I just buy a new Y piece? I don't have a welder so pulling it apart is probably a no-go for me.

Thank you Elwyn,

This is a very common issue, the point where the 2 pipes merge have a flow plate, these are spot welded on and with all the carbon, heating and cooling the plate goes brittle and then eventually snaps off. The issue is it can go back to the Cat and will rattle in the rev range yo have described

You can get it removed but it is best off being there, I have on occasioin opened up the pipe, repaired the pipe and welded back up when I can not get another engine pipe

Yea if it is as above your best bet would be to get a replacement section of exhaust off a later model magna/verada. I believe TH onwards they modified the design or manufcture of this section to avoid this problem. Had this issue on my TE and just replaced it with the Y piece off a TH I think it was, bought it off D-Van...

Just a thought I had while I was on the bus today... Is there any difference in the Y piece between the 3 and 3.5L?

Thanks for the help so far guys, muchly appreciated :)

Sorry to bring up an old thread but dammit this sound is getting annoying! It's definately coming from the exhaust. I'm prob gonna ring a few exhaust mobs over the next week or so, but any suggestions on approx how much I should pay to get it replaced? It's not something I can do myself a I do not have access to a welder.

Here is a pic of the culprit!
http://i10.photobucket.com/albums/a126/BlazingMatt/IMG00077.jpg

And the rest of the pipe just because
http://i10.photobucket.com/albums/a126/BlazingMatt/IMG00080.jpg

I have the same annoying ass sound on my 97 verada!! GRR and im pretty certian its a timing belt tensioner. At first i thought it was an exhaust or something but i got my exhaust checked and its all good. but who knows haha good luck

A good while back, I think there was discussion of a mystery noise which came down to a divider in the exhaust where front and rear bank engine pipes merged into the "Y"....... a poor weld inetrnally let a piece of metal vibrate or even come loose and rattle (it was intended to isolate the gas flow from each engine bank). Could that be the culprit?

Thanks Elwyn, you saved me the trouble, this is a very common issue and by what you describe I would say this

A tensioner will not give the rattle when running, will only do that after a prolonged shut down period such as a few hours or over night

Thanks Elwyn, you saved me the trouble, this is a very common issue and by what you describe I would say this

A tensioner will not give the rattle when running, will only do that after a prolonged shut down period such as a few hours or over night

Will the tensioner noise when cold still be affected by revs? I have what I think is the tensioner noise when cold, but only on idle as it goes away when I take the engine above idle and it comes back when I drop back to a idle. This is definately only on startup as described above.

I have this as well.
Not the tensioner, that was triple checked when the belts were re-done.

Does the Ralliart/VR-X exhaust suffer from this problem?

i have to rattle
1, a high pitch tinny noise
2, a knock not on start up on with reving it but not there under load