Engine Rattle

[recneps]

Hi,

Had my 300tdi P reg since christmas. It runs fairly well (if a little underpowered at times) and apart from having a new alternator around easter its all been fine

Last monday i was unloading the car and had the engine idling and it sounded really rattly. It had been fine the previous day, and had just done an 80 mile drive with no trouble at all. So i opened up the bonnet and the rattling noise sounds like its coming from around the alternator area. It still drves fine and its only really noticeable at idle.

Any ideas? Was wondering if the guy who installed the new alternator had messed something up, as i've since found out hes a bit dodgy.

[listerdiesel]

A rattle suggests that something is loose on the engine, not necessarily the alternator, but that has to be the prime suspect.

Does the noise die off when you bring the engine rev's up slowly to about 1000rpm, or is it there all the time?

Might also be worth looking at the security of the vacuum pump on the back of the alternator, have the brakes been OK since the alternator was changed?

Also, check the alternator pulley for tightness, it will quickly wreck the alternator shaft and keyway if loose as the power impulses at tickover are pretty coarse.

Peter

[thebiglad]

On the TDi 300's the vacuum pump is a separate unit on the right or off-side of the engine, below the lift pump.

[recneps]

Just found today that the coolant level is low. The waterpump is, i beleive, adjacent to the alternator so could the low level of coolant be causing this? Will try topping it up tomorrow morning (didnt want to faff around in the dark this evening)

[listerdiesel]

On the TDi 300's the vacuum pump is a separate unit on the right or off-side of the engine, below the lift pump.

Sorry, I was looking at the TD5 for some reason! :o

Peter

[TEMPL4R]

Flip the belt off and check for play in the pulleys, it's not that obvious with the tensioner taking any slack out. Is the tensioner moving about a lot?

Chris

[ComicalEngineer]

I had a rattle for ages (and a squeak too!).

I had the cambelt changed last week and also changed all of the pulleys, drive belt tensioner and waterpump after suspecting that the alternator bearings were going. Turns out it wan't the alternator but the water pump bearings making the noise.

However, the belt tensioner pulley is notorious for rattling on the 300tdi.

As mentioned above, remove the drive belt (easy) and check the alternator, water pump and tensioner for rattles.

When was the cambelt last changed? 5 years / 60k miles is recommended.

[recneps]

Cam belt was changed about a year ago (have receipts from previous owner)

Will check all the belt pulleys later. Currently sitting in a peugeot garage in Bristol waiting for an MOT on a rather tired motorhome and trying to sort out account numbers. Why are computers so rubbish?!

[Macalac]

Recneps,
I had a similar problem with mine and found that the metal cover over the terminals had come loose. Might be worth checking
Macalac