Noise From Rear - Possible Fuel Tank

Exhaust rubbing?

If I lift the rear seat, it sounds like the noise (quite a racket) is coming from beneath that. Sounds mechanical.

No help necessarily but I walked past an AA van trying to start a car the other day and he had the rear seat up and was doing something with a multimeter in that area. Could he have been checking the feed to a fuel pump that may have been underneath the floor in that area?

Cheers, T i m

Well he could, but would that explain the noise described? I think the most likely fault here is a rubber exhaust hanger has snapped, allowing the exhaust to hang askew and touch the bodywork or whatever.

Steve

I was going along with the OP's "If I boot it, it goes away for a second or two and comes back" and thought that sounded more like (say) a pump being unloaded for a while (with more fuel use when it was 'booted') then reloading when the system re-pressurises / whatever? Only a huge guess mind ...

Cheers, T i m

just had a look. Coming from drivers side rear seat - if I lift the seat I can hear it clearly. I think that the fuel pump is under there - I'll check again tomorrow but maybe that needs replacing.

since internal pumps are insulated by the fuel it is rare to hear them at all. exhaust is first suspect.

I agree. Due to the fact that the noise goes away when the engine is booted. Probably just needs an exhaust hanger replaced to cure the problem.

When booted the engine will twist slightly in it's mountings. Probably just enough to move the exhaust away from where it is striking the bodywork, and then the noise would return as soon as the engine settled back to it's normal position.

AIUI fuel pumps run at a relatively constant flow rate, with excess fuel being returned to the tank, so are not affected by throttle position. Mike.

I should have added that it's also the easiest thing to check. Just go to the back of the car and give the tailpipe a wiggle about.

Steve

It's defo the pump making the racket. I took the cover off in the boot and put my ear right over it....

So when was the filter changed?

30k a go. That is my next task though. I took the pump out and checked it, put it back, and it's working with less racket. It's the whizzing that it is making, it was so loud....

I am start>> >>>

It could be that as its sort of a dry pump noise.

Jim

The VW trained technician, in the house, has gone skiing for a couple of days he will be back Thursday. Ill put the question to him then. I'm sure he would have dealt with such problems. Or if I get up town tomorrow Ill ask his new old boss.

r

thanks for that Rob. After removing and re-inserting, it's not as noisy, but is still pretty noticeable. I wonder whether a replacement would make the same noise - I can buy one for £50 unless can find from a scrappy.

If your man is a VW chap - I also have the rear parking sensor alarming all the time when in reverse - just started on Saturday!

Thanks.

Ok Ill ask his boss, (who was the service manager at a VW dealership)

Whats there is a low pressure lift pump. and It could be the filter that's making it over work. Also check the lines for any problems.

Sensor - This could be a faulty sensor and the best way to test this is put it on the computer. Is it a manual or triptronic gearbox?