Engine rattle from 2500rpm to 6000rpm

[Szybki_one]

Hi everyone,

I've recently purchased a 156 2.5 6spd manual. I have noticed under heavy acceleration between 2500 and 6000 that I have a rattle towards the drivers side of the engine bay, only happens when the engine is under load, the timing belt and all pulleys were done 25,000km ago. Could a idle pulley be loose? Wouldn't I hear it at idle if something was loose?

Any ideas?

Thanks I'm advance 

[poohbah]

Can't help with the rattle, but wanted to say what a great car (I had my 6sp v6 for 3 years - best car I ever owned). And also to tell you to make sure you check the fuel lines and fuel injection rail - so yours doesn't go up in smoke like mine did!

[bazzbazz]

As you've had the timing belts done, and it's only under load usually means one of the accessory belt pulleys is dry or worn, casing the belt to skip and chatter on the belt tensioner.

Remove the accessory belt and give the 2 idler, tension and A/C pulleys a good spin. They SHOULD NOT spin more than a couple of revolutions, due to being well packed with grease. If any of them spin freely, sound rough, or have any play in them, time to be replaced.

A worn A/C pulley can be a bitch, because you here the rattle faintly, so you turn everything off (including the A/C) so you can hear the rattle better. But as the A/C pulley usually only rattles when the compressor is on, and under load, you all of a sudden can't hear it. Also as the A/C compressor is always turning on and off to keep a constant temp in the cabin, the bloody rattle keeps coming and going . . . .and you can never constantly replicate it for the mechanic! 

Evil minded bloody things . . . .aren't they?   

Baz

[Szybki_one]

Thanks Baz ang poohbah.

Okay I'll check all the pulleys and see if they are worn. Also I've read about the exhaust bracket issue? I'll check that as well to ensure I'm not chasing my tail.

Thanks,

[Szybki_one]

I've looked back through the service history and the drive belt tensionors were changed. Should I assume the belt was changed as well?

[poohbah]

You would hope it had been done, but you would also imagine it would have been shown in the service history. If you contact the worskhop/s recorded in the log books, they should have a record of everything they have done. Hopefully peace of mind for the cost of a phone call.

[Szybki_one]

I went back to them and they said the following " timing belt and drive belt tensionors replaced" so it's abit hard to work out if it has. Anyway I will check it on the weekend along with the exhaust bracket to ensure that hasn't snapped.

[Craig_m67]

Just to throw a curve ball, I put in a new aux belt, idlers and tensioner a year or so back. The new tensioner was super noisy and so I reverted to the old one.

Best way to know for sure is simply to remove the aux belt and start her up. If the noise. Remains it's something other than this stuff (obviously).

You can run it for a while without having the belt on, just be aware that the alternator will not be charging the battery.

[Szybki_one]

Noticed this morning driving to work that I only had the noise in first and second and nothing in third. Can't wait to get under and find the source!!

[Mika]

Have you checked the top stabiliser bar that secures the engine. It may be the rubber bush is worn. It is located on the Lhs when looking from under the bonnet, and mounts to the rh strut tower. The part is not that expensive.

Good luck,

Mika

[Szybki_one]

Hi Mika.

Checked that. Brand new one fitted not that long ago. Looks in good condition, it's mounted quite close to the timing cover thou?

Thanks,