cup 172 - broken cambelt, fixed but wtf is this noise?

[chris79]

Right,

You might be aware my cambelt snapped at 24,000 miles.. got the car back from Renault last week, they fitted a new cylinder head etc...

Anyway, since getting it back, both myself and my girlfriend have noticed a sort of... quiet rattling sound which comes from the engine around 2500-3000rpm but only if the engine is under load (i.e. foot down)...

its a very very quiet rattle, i'm wondering tonight could this be the engine pinking (pre-ignition)? I used to get this on my r5 turbo when using too much boost...

Is it possible that they've screwed up the timing, or theres some additional engine damage causing it which wasn't fixed as part of the new cylinder head replacement?

cheers.

 

[172 Dave]

oooer my friends VR6 golf had this.....sounded exactly like pinking after a rebuild only under load and like a quiet rattle from behind the dash, turned out to be the small ends chatterin away to themselves. Hope urs is something more simple mate..

 

[chris79]

oooer my friends VR6 golf had this.....sounded exactly like pinking after a rebuild only under load and like a quiet rattle from behind the dash, turned out to be the small ends chatterin away to themselves. Hope urs is something more simple mate..

thats exactly what i have...

 

[172 Dave]

Chris


His was a VR i know completely diff cars etc but it really did sound like next to nothing at all it went to 4 vw specialists to be looked at as neither of us believed them it had only done 55k!
Was a real faint chattering away as though behind the dash etc but ESP underl load in the intermediate gears.
Id take it back mate, or failing that and dependant on your location take it to Mike at rentech see what theory he comes up with. Trust me i am one sceptical sod but i'd trust Mike!

 

[steve a]

Could of damaged the big end /small end bearings (like suggested).i.e if the valves jammed down on the pistons causing the force to > rods > bearings . Could be a sign that these are damaged, but I would expect more of a knocking sound. Could well be pinking though. Best get it checked out.

 

[chris79]

basically theres 2 sounds.. theres the quiet rattling from 2-5k if i accelerate in 3/4/5th gear... and theres a knocking sound present when the engine is ticking over at idle which comes and goes which i've noticed. The problem is I don't know if it's me just being sensitive and looking for a noise, or whether it really is there.. but even if it's a small insignificant noise, at the end of the day i'm worried this = broken engine, and how do I convince Renault to fix it or give me a new engine? In all honesty I wished they'd put a new engine in rather than just replace the cylinder head, but they insisted that the head was the only thing damaged...

 

[172 Dave]

Simple mate, take it to Renault and ask them to run it side by side with an identical model. That way they cant slip out of it, if its knockin and rattling then it clearly isnt right.

 

[JAY172]

the valves on the new engines are very easy to bend so i doubt if a cambelt snap could cause any damage to big or small ends etc. compare yours to another,cant somebody here meet you or something?

 

[bx16v]

You might be aware my cambelt snapped at 24,000 miles..

Is it any way to prevent this??

 

[hkka]

Excuse me, may I know what does the car feels like (or what will happen) if the cambelt snapped?

 

[Friction]

it wouldnt move..... lol

car would cut out, you'll probably get a noise from the engine, your instrument panel will light up, you'll lose brake efficiency, power steering, etc

you'd know about it!