Hi, I am experiencing a slight problem with my Grande Punto 1.9 Sporting

At idle there is a horrible loud tapping/squaking sound coming from the engine bay. Reving the engine a little seems to quiet it down but once it goes back to idle the noise re-appears.

I'm inclined to think that it's the injectors that may be causing it, putting a screwdiver onto each injector and it seems like the sound from 1 and 2 is different to 3 and 4, and disconnecting one injector seems to make the noise disappear.

Has anyone experienced these issues before or have any idea what could be causing it?

It's a 57-plate 1.9 Multijet with 75K miles. The cambelt and water pump have already been replaced.

Any advice is appreciated, Thanks.

Would you say it sounds like an old ford transit or old ford escort / orion 1.8 diesel, they squeak alot!

If thats the case, our engines (i have a jtd 16v) should not do this and it sounds like you have isolated the problem.

Hi,
Does it sound internal or external to the engine?
one cause of knocking noises is a degenerated inertial damper pulley on the crankshaft. This is a three part metal/rubber/metal pulley that drives the aux belt. If it's failing you can sometimes find a resonance by vety slowly rising the revs from idle. Disconneting a injector may be disturbing the torque pulses and changing the noise.

Robert G8RPI.

g8rpi said:

Hi,
Does it sound internal or external to the engine?
one cause of knocking noises is a degenerated inertial damper pulley on the crankshaft. This is a three part metal/rubber/metal pulley that drives the aux belt. If it's failing you can sometimes find a resonance by vety slowly rising the revs from idle. Disconneting a injector may be disturbing the torque pulses and changing the noise.

Robert G8RPI.

Click to expand...

The noise seems to be external, opening the bonnet and pressing down on the engine cover seems to reduce the noise significantly.

Oddly though, I've just started the car again and the noise was not there at first but only after a while it returned, so it seems to be happening only once the engine has warmed up a little!

I'm thinking same as Robert crank pulley ,metal bonded to rubber bonded to metal, can be affected by temperature changes.