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Engine Knock / All In My Head..


ClarCE

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Hi all,

 

After a couple of weeks with the Zed now, I'm still loving every minute, even as I come across niggles such as weird squeaks and the bose giving up - all fixed / about to be.

 

However, I have noticed that when pulling away in 1st and second when I hit 1.5 - 2.0 K revs, sometimes I get a knocking noise from the front somewhere - at least I think its the front. I thought to start with maybe I had the clickly rear CV joint problem, but I imagine from what I've read that would sound more like one of those dog trainer clicky things, where as this is more like someone knocking on a big wooden door..

 

Any ideas? I thought maybe the exhaust was bouncing around as the low revs throw some pretty good vibrations through - just like in most big engined cars..

 

Any light that could be shed - much appreciated..

 

Chris.

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could be a numerous of things, best thing is try and locate exactly where it is bud. Im guessing if it was the exhaust it would be throughout not just on earlier revs. It could possibly be piston slap which is caused by a worn cylinder wall in which case try a higher octane or get it checked immediatly. But as said it could range from absolutely anything unless you can locate where exactly the noise is coming from. If it was me Id just take it to a garage and get them to judge it for you thats your best bet as we cant examine the car over the web.

 

Oh and welcome by the way

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could be a numerous of things, best thing is try and locate exactly where it is bud. Im guessing if it was the exhaust it would be throughout not just on earlier revs. It could possibly be piston slap which is caused by a worn cylinder wall in which case try a higher octane or get it checked immediatly. But as said it could range from absolutely anything unless you can locate where exactly the noise is coming from. If it was me Id just take it to a garage and get them to judge it for you thats your best bet as we cant examine the car over the web.

 

Oh and welcome by the way

 

Thanks for that, I hear what you're saying - its going in for a service in next couple of days so I'll ask them to drive it and listen. Only happens when driving btw, doesn't do it when revving in neutral.

 

I was thinking that if they can't do anything, then I'd ask someone on hear to have a listen. The good news is I've got a comprehensive warranty (Tesco Finest!) so if theres anything serious it should be covered..

 

Also, It's currently got 99 Octane in it and has done for the last 3 fill-ups since I got my mits on it.

 

Cheers,

 

Chris.

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More info needed :blush:

 

engine mounts

exhaust knocking

droplinks knackered or dry

track rod ends

you forgot to open the passenger door and your missus is knocking to get in

worn suspension bushes

etc etc

 

deep knock ?

fast or slow ?

does it stop if you ease off the accelerator ?

 

:teeth:

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More info needed :blush:

 

engine mounts

exhaust knocking

droplinks knackered or dry

track rod ends

you forgot to open the passenger door and your missus is knocking to get in

worn suspension bushes

etc etc

 

deep knock ?

fast or slow ?

does it stop if you ease off the accelerator ?

 

:teeth:

 

lol, definitely not the Mrs! She's not a 'car fan' although I know she secretly likes it!

 

As for the knocking (of the car) its deep in a sound sense.. seems to increase in speed as I accelerate. On my 30 mile trip home tonight, I couldn't always replicate it but when I did I couldn't get it to do it in any gear other than 1/2.

 

It does stop if I stop accelerating all together..

 

I'll let you know what I find around the front when I get chance to get on the stands and pull the wheels off..

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Yep, forget that comment - I just listened to a clip on another forum of that noise, and its not it.

 

Just been out doing some testing - tried to record it, but phones crap.

 

Test 1

Changing from Neutral to 1st to 2nd normally, applying acceleration as changing - between 1500 & 2000 - noise noticeable, even from cold.

 

Test 2

Changing from Neutral to 1st to 2nd quickly, applying lots of power - noise barely noticeable

 

Test 3

Changing up in any gear, but not accelerating until fully off the clutch - noise not noticeable.

 

I then did Test 1 and 2 again - noise was back

 

Test 4

While in 2nd, got to between 1500 & 2000 rpm, and slowly pressed in clutch while keeping the power constantly low - noise louder, and could feel it coming back up through the clutch pedal.

 

So I think I may have pinpointed it - got to be something to do with the clutch, anyone think its the clutch itself, or possibly this release bearing, which is noisy (but not much) when im idling in neutral..

 

Cheers in advance, feels like im getting somewhere, I hope!

 

Chris

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Thanks for that m8, that post on the other forum is what made me think it was the fuel dampner. However I don't get it at all at idle - just clutch bearing noise that reminds me of an knackered XR3i I owned 10 years ago!

 

I'm thinking its clutch related now, following the testing I did in my last post.

 

There is a sound clip in that other forum, and that guys engine sounds seriously sh**ged. Thankfully (touches wood) mines nothing like that, and definitely appears clutch related..

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is this a brand new car? If not, do you have the service history? Any noises going over bumps in the road, or is it strictly related to being on and off the clutch?

 

2004 - 24500 miles, full dealer history.. No problems with bumps, just clutch..

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is this a brand new car? If not, do you have the service history? Any noises going over bumps in the road, or is it strictly related to being on and off the clutch?

 

2004 - 24500 miles, full dealer history.. No problems with bumps, just clutch..

 

then you can rasonably assume it's not the mounts, etc. If I had to wager a guess, given the year of the car, I would think a faulty throw out bearing. Quite common. While in there, check the obvious things such as clutch disk condition, pressure plate fingers (to make sure they are all even and one/some have not collapsed) as well as torque on the flywheel bolts

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is this a brand new car? If not, do you have the service history? Any noises going over bumps in the road, or is it strictly related to being on and off the clutch?

 

2004 - 24500 miles, full dealer history.. No problems with bumps, just clutch..

 

then you can rasonably assume it's not the mounts, etc. If I had to wager a guess, given the year of the car, I would think a faulty throw out bearing. Quite common. While in there, check the obvious things such as clutch disk condition, pressure plate fingers (to make sure they are all even and one/some have not collapsed) as well as torque on the flywheel bolts

 

unlikely to be the mounts as these are usually noticable on deceleration aswell as acceleration, but i dont understand why the clutch would only cause a prob in 1st and 2nd ? unless its driving more and momentum helps in the higher gears

very difficult to diagnose a noise via the net though :surrender:

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is this a brand new car? If not, do you have the service history? Any noises going over bumps in the road, or is it strictly related to being on and off the clutch?

 

2004 - 24500 miles, full dealer history.. No problems with bumps, just clutch..

 

then you can rasonably assume it's not the mounts, etc. If I had to wager a guess, given the year of the car, I would think a faulty throw out bearing. Quite common. While in there, check the obvious things such as clutch disk condition, pressure plate fingers (to make sure they are all even and one/some have not collapsed) as well as torque on the flywheel bolts

 

unlikely to be the mounts as these are usually noticable on deceleration aswell as acceleration, but i dont understand why the clutch would only cause a prob in 1st and 2nd ? unless its driving more and momentum helps in the higher gears

very difficult to diagnose a noise via the net though :surrender:

 

Yeah, I appreciate that - I used to be pretty hot on the X25XE GM engine, and it was never easy diagnosing on the web!

 

Found this post on here earlier, guys explaining the exact same thing I think - typically it doesn't say if he got it fixed! So I've PM'd, although he doesn't look like an 'active' member...

 

http://www.350z-uk.com/forum/viewtopic.php?t=10635

 

I'm going to take it to my mechanic next week, he'll stick it on his rolling road and have a listen with the confines of the shop.. I'm pretty convinced its the clutch, and am willing to swap the flywheel and the whole clutch (both bits) + bearing when I go down that route..

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