DB9 engine makes a tapping/clunking sound at idle

[TBM850]

Hello all,

With the bonnet up, my 2013 DB9 US left hand drive gives a "clunk" at idle every 8-10 seconds. Sometimes the engine RPM varies slightly afterwards.

Car seems fine. It sounds like something opening and closing rather than engine valve issues.

I have a video but likely too large to upload.

Anyone experience this?

Cheers

Paul

[Watermead]

Noticed a similar noise I think on my Rapide the other day. Have you tried it with the A/C turned off? From what I've read the A/C compressor engages with a bit of clunking noise. I turned my A/C off and the noise stopped.

[TBM850]

My goodness. Thank you! I will try that. It does sound more like a scheduled "normal" valve or clunk rather than an engine malfunction. Much appreciated. Paul

[camel_landy]

From the description I'd suggest the AC compressor too. The simple way to test is to turn off the AC and see if it continues.

The clunk is from the clutch engaging and I can only assume it's a bit of a Ford 'thing' as I've had a Volvo & Fiesta from the same era, which did exactly the same. The engine idle is due to the additional load from the AC compressor doing its job.

HTH

M

[Nigel_O]

If the clunk is every 8-10 seconds and it IS the aircon, you might find it needs a service / regas. 8-10 seconds sounds a bit too frequent for the compressor to need to kick in to maintain pressure.

[TBM850]

Those are all very helpful comments. Thank you! I will get it properly serviced with R134A.