Worrying Noise From Just-Bought 2Nd Hand 2.0 D4D 2014 Avensis Icon

[2912pwil]

Just bought a 64-plate 10k miles 2.0 D4D Avensis Icon. Very nice: But... drove some 250 miles directly home: I stopped briefly for fuel (Diesel, I have receipt) and then at two motorway services for pee breaks. I am a retired 67-year old pensioner, IaM & Rospa tested, and do not drive in a manner unsympathetic to any vehicle. During the journey there were no strange noises, no unexpected warning lights and the coolant temperature gauge was steady in the middle of the range after it had warmed up. Everything else operated satisfactorily.

However, on getting out at home a clicking/cooling-down-contracting noise was obvious, from the engine-bay area, sounding (to me, I am not an expert in these matters) like some metal/metallic device(s) cooling down. (I had not noticed the noise during the journey nor when filling the tank). I returned to the car with my wife some minutes later & it was still easily audible. No smoke, no steam, nothing else untoward - I opened the bonnet. This morning I checked the oil & coolant: Levels and appearance normal and satisfactory.

The only time I've heard a similar sound was about 25years ago from a 1300 Police Ford sierra that had been trying to catch me (guilty m'lud, no excuse..28 day ban, reformed now thank you...) at the bottom of the M1 at over 100mph. i.e. a heavily overstressed engine..

Any ideas what it is?? I've emailed garage “inviting their thoughts” & won't drive it today or tomorrow: Turbo going?? It had allegedly just been serviced by them, car supermarket. Weird..

Any thoughts, ideas or suggestions gratefully received.

[ToyotaAuris]

Thats absolutely normal. Happens on all cars, small tick tick sound. Not sure what the science and purpose of it is but I can assure its not a problem.

[Druid Boy]

As above, it is simply hot parts contracting as they cool. Completely normal and nothing to worry about.

[yossarian247]

I wonder if the DPF had been regenerating just before you switched the engine off? The regeneration cycle of particulate filters does require them (and the engine) to get very hot. If so it's completely normal. They can cause some burning smells too.

[2912pwil]

Thank you all, especially Yossrian247:

I've had a 2.2 D4D avensis for 6 years and whilst I agree cooling-down clicks are common what I heard was much much louder!

Having looked up DPF active regeneration it sounds very like it.. Much obliged...

[yossarian247]

Often when cars are for sale or being prepared for sale at a dealers/car supermarket they get shunted round quite a bit; started up, driven a few yards, switched off while still cold, every few days over the course of days, weeks, or however long they take to sell. It could well be that yours chose it's first decent motorway run in a long time to regenerate its DPF, not surprising really.

[theoilburner]

I've noticed this on my 2012 D4D too - happened two or three times in the last couple of weeks. Haven't heard any car do that in a while, but I'm not too concerned. Our Prius doesn't do that - so it could well be DPF related.

[cmia]

the tick tick noise is mostly the metal expanding cooling and contracting..

cat / downpipe.. dpf etc