Engine Clatter

[c.lday44]

Hi all. Over the last few months I've noticed a slightly concerning clattering noise, most noticeable upon cold start, goes away somewhat over time (presumably as it warms up), increases in frequency as I press the throttle. It's a really unhealthy rattley clattering sound. Sometimes it doesn't do it, but most of the time it does. When it doesnt, it runs smooth as butter. I think I've narrowed it down to the driver's side of the engine but sometimes it sounds like it's from the throttle area so honestly god knows. The car has just 68,000 miles and 99% full service history. I currently run it on 5W-30 Castrol oil, and it's a 2007 SE Manual 1.4 i-DSi.

My thoughts are chain slap or something, though I know these engines are known for piston slap. The car still drives great, pulls to 6k rpm on the very rare occasion I go that high. It's just a combination of that clatter and the noisy input shaft bearing that make it sound like a very unhealthy car!

What do we think? It's most noticeable inside the cabin, especially when I put a little bit of throttle on. Under the bonnet I can barely hear it, though I haven't had the throttle pressed when under the bonnet (obviously)

If it's chain, I'll replace the tensioner and maybe the chain too (Could it be stretched, or just a loose tensioner?)

If it's more serious, well, buggar.

[Lord Voltermore]

I'd get an experience mechanic to take a look and have a listen  before going to the expense of replacing a  tensioner or timing chain etc on a  17 year old car. Or indeed before going to any other significant expense hoping it might cure it.  (  But others may suggest things you can try at little or no cost. )
 
The mechanic  may put the car on an OBDll diagnostic code reader and find one or more of several other possible reasons its running rougher than it should at some speeds, and therefore noisily . There could be a sensor,such as air flow, exhaust gas  oxygen level etc  giving a dodgy reading, making the ECU meter a less than ideal fuel/air mix  , too fuel rich or too lean .Or a physical problem such as  a dodgy coil pack, spark plugs, fuel injector, fuel pressure, EGR( exhaust gas regulator)   etc. 

Regular servicing sometimes doesnt amount to much more than oil and filter changes and wouldnt necessarily  prevent such problems.

[c.lday44]

I'd get an experience mechanic to take a look and have a listen  before going to the expense of replacing a  tensioner or timing chain etc on a  17 year old car. Or indeed before going to any other significant expense hoping it might cure it.  (  But others may suggest things you can try at little or no cost. )
 
The mechanic  may put the car on an OBDll diagnostic code reader and find one or more of several other possible reasons its running rougher than it should at some speeds, and therefore noisily . There could be a sensor,such as air flow, exhaust gas  oxygen level etc  giving a dodgy reading, making the ECU meter a less than ideal fuel/air mix  , too fuel rich or too lean .Or a physical problem such as  a dodgy coil pack, spark plugs, fuel injector, fuel pressure, EGR( exhaust gas regulator)   etc. 

Regular servicing sometimes doesnt amount to much more than oil and filter changes and wouldnt necessarily  prevent such problems.

I may end up doing this but if I can cure it myself all the better, I'm not afraid to get my hands dirty! I'm going to put some decent fuel in next fillup (I use Tesco/Sainsburys E10 usually, cheapest stuff I can find haha), maybe some redex or something. I do have an OBD reader of my own, there's no codes but I might watch the idle RPM (it has monitoring). Spark plugs, I replaced half of them (before realising I didn't have the tools to get at the back ones easily. Buggar.), It's never misfiring I don't think. EGR could be worth checking as it's in the region of that!

Thanks!

[olduser1]

Stop pressing the parts catalogue, have the Jazz diagnosed by a mechanic.

[c.lday44]

Stop pressing the parts catalogue, have the Jazz diagnosed by a mechanic.

I haven't changed a single part since it started this noise. I'm more than willing and capable to solve it myself, thankyou. I narrowed one clicking down to the throttle area today, and the rest seems to be from the top end of the engine, which I'll diagnose at a later date.