Awful metallic noise coming from belt side of the engine

[Cliomaxx69]

Hi, I started my car this morning and heard a weird metallic noise. I got scared but had to go anyway. I ended up turning the engine off at some point and starting it up again and the noise was gone. It came back when I was at a red light, I switch the A/C on and it disappeared straight away. Any ideas?

Thanks.

 

[hopgop1]

Sounds like a pulley to me?

 

[Cliomaxx69]

I'd think so too, how much of a pain is it to fix?

Do you know if it's dangerous to drive it like that?

 

[hopgop1]

Would think it could throw the belt if it locked up, potentially taking out the timing belt. Although I did drive my old 182 with a squeaky aux belt for a week or so and didn't have any issues.
Hopefully someone more qualified can answer with more certainty though, wouldn't take my limited knowledge as gospel.

 

[Amos91]

Probably your AC compressor if the noise changes when the clutch engages.

 

[jameswrx]

Yes, as said sounds like ac pump (pulley). Don’t leave it as it will wipe out your timing belt when the pulley fails, belts jumps and goes through lower timing cover.

 

[Cliomaxx69]

Does this require special attention being the F4R or should any Renault shop be able to do it?

 

[Cliomaxx69]

Looks like you can't buy the only the pulley so I need to replace the AC compressor? Any chance the pulley just needs to be tightened? Don't really fancy paying 250 for an AC pump 😦

 

[Amos91]

Just get a used compressor and lob it on.

 

[Martin_172]

Have you confirmed its definitely the AC compressor? does the noise come and go with the activation of the AC? As above just stick a second hand AC compressor on it.

Make sure the fuel rail guard is tight as these can also cause a metallic rattle when they are loose

 

[Cliomaxx69]

I have no idea, basically I started the car and heard the noise, drove for 5mn before stopping because it sounded really bad. I turned the car off, turned it back on and to noise was gone. Keep driving, go to a drive through, the noise comes back while waiting in line. For some reason I turn ON the A/C and the noise is gone. I drove about 100km since and never heard it again.

 

[Martin_172]

check the fuel rail guard then.

 

[Cliomaxx69]

How would the fuel rail guard make this noise?

 

[Martin_172]

How would the fuel rail guard make this noise?

if its loose and rattling

 

[Cliomaxx69]

I'll check but it sounded like something spinning was grinding

 

[Martin_172]

I'll check but it sounded like something spinning was grinding

to me it sounds exactly like the fuel rail guard rattle, and the fact its only happening at idle and stopping when the AC raises the idle, to me points to that!

 

[Cliomaxx69]

I've had to remove it and refit it many times recently, wouldn't be surprised if I forgot to tighten it properly

 

[Cliomaxx69]

Just checked and it's tightened good

 

[bozothenutter]

Sounds like the aircon pully clutch might not be releasing with aircon off.
Had this on an Alfa 156 once, nearly ruined the family holiday!
AA wanted to fix it with a new pump, but car was going anyway.
Alfa mechanic mate said get a shorter belt and bypass aircon pulley. French garage didn't wanna know three days of grief then fixed it myself in 30mins...

 

[Cliomaxx69]

Not sure I follow, you fixed it with a smaller belt as the dealer said? So you post AC?

 

[bozothenutter]

Not sure I follow, you fixed it with a smaller belt as the dealer said? So you post AC?

sorry, that was on an Alfa, generally this means a new pump