Auxiliary Belts And Rattling - Mondeo Mk3 2.0 Tdci

[Jezzic]

Evening all!

TLDR: My mk3 TDCI is producing an intermittent rattling noise on idling, which disappears when I raise the revs slightly by depressing the throttle. Appears to come from the right-hand side of the car, and seems to be external to the engine. Any theories?

The long version:

This week I needed (i.e. badly wanted!) a new car to replace my battered 20-year-old Corolla. I ended up with a mk3 Mondeo 2.0 TDCi, 115PS, 2006-plate hatchback in green. Great cosmetic condition, 136,000 miles on the clock, with no service history apart from last MOT (March 15), which it passed with a couple of advisories, one of which is the noise I'm asking about here.

Okay, so I took a risk, but the car looks great, is much newer and better-equipped than anything else I could have afforded, and cost me just £450!

It has a couple of issues, but I figure it's worth spending a bit of money to keep this one running. My theory is that the first owner was a business driver/high miler, as the car is in great condition and the passenger and rear seats have hardly been used. It then seems to have spent about 8 months in the ownership of a young man from a family of traveller types who own horses and buy and sell vehicles - but who don't seem to have done much maintenance or servicing on this car (evidenced by the fact that it needed a thorough cleaning inside and out after purchase, but scrubbed up great!).

I was relieved to learn that the mk3 TDCI has a timing chain rather than cambelts. However, it appears that one might still need to check the condition of the timing chain (£200 bill?), and the replacement of the auxiliary belts is due at 125,000 miles (also £200 bill?).

As I mentioned in my summary above, there is this metallic rattling noise when idling. It's not there all the time - usually takes several seconds of sitting at traffic lights for it to begin, and it comes and goes. It can be relieved by raising the revs slightly using the accelerator pedal, and also seems to vanish when the clutch pedal is depressed.

With the bonnet up, the noise seems to be coming from the area of the auxiliary belts on the right-hand end of the engine.

Everything seems to be working; it's just this noise. The car stops and goes just fine and has plenty of oomph.

Worth pointing out: the car pulls to the left noticeably, pretty much all the time.
This has not been cured by having the wheels aligned or replacing the tyres worn by the misalignment. The only time it has not done this is on a surface with a right-hand camber.

The left-hand pull also occurs if I brake sharply (once the car has shed most of its momentum; it then kind of "digs" to the left just before coming to a complete stop, with the steering wheel twisting to the left). Whilst driving I find myself compensating, and at times if feels as if I'm fighting the steering a little.

I don't remember having anything like this or noticing heavy power steering on the brand new TDCi estate I hired for a week whilst living in Germany back in 2002, which I put about 1,500 miles on - I was very impressed by that car, and that's one reason why I bought my current Mondeo.

So I'm wondering if the rattling is anything to do with the drive to the power steering pump which in turn might contributing to the steering issue. Clearly the car needs an oil and filter change which I will probably do myself. A friend (trained mechanic) drove behind me yesterday and said he saw the odd puff of smoke - not sure how much oil it's consuming but it's in the middle of the dipstick, albeit quite black.

Anyway, I'd be happy to clear up the rattling on this thread and investigate the leftward drift separately.

PS To avoid wasting time with comments about the risks I've taken, can we please just assume I've done all the self-beatings and sleepless nights about buying a car with no service history from dodgy people - I've got good reasons for not wanting to put any more time or energy into looking for a car, and would just like to know what I might need to do to get this running as sweetly as possible (or indeed if the issue is one I can ignore safely).

Over to you! Thanks in advance for your suggestions!

[Jezzic]

Okay, so after further research, the tyre wear could be due to suspension issues - I get a "clunk" from the left rear suspension whenever I go over a sleeping policeman or similar bump, so that might be the subframe bushes.

And I understand that the dual mass flywheel can produce rattling noises - would this happen when idling?

[stef123]

The rattle at idle is from the crankshaft pulley, very common thing.

[Jezzic]

Thank you, Stefan - have found some other articles that talk about this too, so that has put my mind at rest. B)