Join Date: May 2007
Location: Newcastle, England
147 Diesel - Pop at switch off
When I turn the engine off, all seems normal. No odd sounds, sqeels or run on etc. BUT, right at the last second, as engine seems completely dead - there is a loud BOP sound. A bit like someone closing the boot of the car parked next to you.
It does it every time I switch off, without fail.
I've observed the engine with bonnet up, as I switch off. The 'BOP' appears to be caused by a release of pressure into what looks like a large diameter intake pipe? The pipe runs up from the lower right of the front of the car, you can put your arm up into it! There does appear to be a small heat exchange matrix a short way into the pipe, sort of level with the bumper, but apart from that there are no obstructions in the pipe and it runs all the up, back along the side of the car and then 90 degrees left and into the side of the engine.
When you switch the engine off, the section of pipe imedietly next to the engine seems to swell slightly then shrink and it's this that's causing the 'BOP' noise. There can be no pressure build up in this pipe as it's completely open on the far end under the bumper. But there must be quite a release of pressure into it to make this noise.
It wasn't doing this until about a week ago! So it's not normal! I've compared the engine off sequence with other TD's but they're all annoyingly quiet!
Can anyone shed any light on this one?
I am suspecting something to do with the turbo? The only thing I can think of that may be related, is that I went through an alarmingly larger than expected beginning of puddle last week which showered the whole front of the car in water! I wonder if some has got into somewhere it shouldn't have ....
Any comments appreciated, even if you can listen to your 'switch off' noises and tell me they're the same or different?
This is a 147 JTD 16V Multi Jet.