Bang & Puff of Smoke - What's Wrong?

Mercmartin

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This evening my seventh hand (!) K-reg 320TE, with 190,000 miles on the clock, produced a bang followed by a puff of smoke from under the bonnet as I started it up. The engine kept running as if nothing had happened and sounded and felt fine as I drove the short route to my destination. There were no apparent leaks, insofar that there were no pools of liquid under the car where it had been parked all day. On arrival after about 15 minutes of driving in town traffic I opened the hood to have a look, but there was nothing immediately visible, but then I don't know what to look for. No funny smells at any point either.

I only a couple of days ago had a lot of work done on the car, including the exhaust down pipe refitted as the catalyser heat sheild was rattling. I also had the gasket and o-rings under the timing cover and the rocker cover gasket set replaced.

Does anyone have any idea what this could be? What should I look for? Any advice would be very gratefully received.
 

television

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Welcome to the forum, I would have said that your car back fired hence the puff of smoke, it could be slightly to far advanced
 

Bolide

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Possibly a backfire. What colour was the smoke?

I'd check underbonnet wiring to make sure the loom isn't disintegrating. This tends to show up when it's been disturbed - ie, after work on the car

Nick Froome
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BarryG

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Where would the puff of smoke come from under the bonnet though?
Could understand out of the exhaust tail pipe.
 

television

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Where would the puff of smoke come from under the bonnet though?
Could understand out of the exhaust tail pipe.

No when they do this it blows back out of the air intake box
 
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Mercmartin

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Thanks all for your replies! I guess it could have come from the tail pipe; it seemed to come from under the bonnet, but I can't be sure. The smoke was white/light grey as far as I could see (it dissipated very quickly). Definitely not black, and didn't seem blue.
 

television

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Thanks all for your replies! I guess it could have come from the tail pipe; it seemed to come from under the bonnet, but I can't be sure. The smoke was white/light grey as far as I could see (it dissipated very quickly). Definitely not black, and didn't seem blue.

I posted with the answer the same time as you, see how it goes.
 

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