Whistle

Newbie Joined: 08 Jul 2005 Posts: 11

Hi guys,

I've just come back to Renault after time with a Xantia, but I've discovered an annoying problem with my 98 Laguna 1.8 8v.

When I change gear, there is a brief 'whistle' type of noise. At first I thought it was the clutch release bearing, but I can replicate the noise by leaving it in 2nd and dabbing the throttle to create a 'kangaroo' effect which causes the engine and gearstick to rock back and forth. Not a massive amount, like bulkhead to radiator, but more than I think would be normal.

Could anyone shed any light on it, and what would be involved in putting it right.

Thanks for any help

Phil

Newbie Joined: 08 Jul 2005 Posts: 11

bump

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

does this noise happen when u basically take your foot off the throttle to change gear?

If so the whistle could be a leak around the inlet manifold. High engine speed, suddenly shut off by you taking foot off throttle, leak allows air in and whistles.

It's one thing to check anyway.

Newbie Joined: 08 Jul 2005 Posts: 11

JB, thanks for the reply.

If I keep my foot on the accelerator, the whistle comes when I dip the clutch to change gear.

If I take my foot off the accelerator before changing gear, the noise comes as I lift off instead of when I dip the clutch pedal.

So, the noise comes when the load is released. At low load, i.e pootling along, there is no noise.

I can see how it might be the inlet manifold, I'll have a look.

I thought it may be an engine mount?

Mr Quoter-vator Joined: 16 Feb 2004 Posts: 7405

well going by description "whistle" i wouldnt say engine mounts whistle.

squeaking yes.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

I say ISCV operating.

a 98 would be an MPI set up, make sure the pipe from the TB to the air filter housing is secured and make sure the cliups on the filter housing are secure.

Newbie Joined: 08 Jul 2005 Posts: 11

thanks for the info guys, I'll have a look.

Newbie Joined: 08 Jul 2005 Posts: 11

Today I finally got it on a ramp to have a good luck.

The front pipe is cracked at the weld where the front pipe is welded to the flange that bolts to the cat.

The rubber mount on the front of the dog bone has sheared which is allowing the engine to pivot, which I guess caused the cracked weld. I'm pretty sure the squeak/whistle is the exhaust moving as the engine rocks forward/back.

To remove the dog bone, is it held on by just the bolts that go through each rubber mount?
The rear bolt appears to bolt directly into the chassis, or is the nut hidden inside the bracket?
Will I need to support the engine?

Cheers.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

strange for a broken exhaust to whistle but it could happen I suppose.

Anyway yes 2 bolts. The chassis side can go into either a captive nut ot a loose one, but if you can't see the loose one then it will be captive. just hope it doesn;t shear (it shouldn't).

no need to support the engine.

Newbie Joined: 08 Jul 2005 Posts: 11

Just to complete the story, I managed to change the dog bone OK.
The old one had sheared at the front mounting, the bottom one of the two rubber isolators. Doesn't seem to make as much difference as I thought. The gear stick still seems to move about 1-2" under acceleration.

The whistle/squeak was still there though.

Had the front down pipe replaced and this cured the problem.

The weld where the pipe fixes to the cat flange had almost sheared off.

The fibre disc at the manifold flexible joint had worn a serious groove into the front pipe, I think this is what was causing the noise.

So, alls well. (at the moment Rolling Eyes

)