Banging from the back

[Pacman1972]

Have just started getting a banging from the back when starting up the engine.
It's more of a thud than a bang, kind of like of something heavy falls over in the boot.

Only thought was pressure in the tank maybe.

Anyone experienced anything like this?

[Jonny cobra]

Hi Have you looked at the rear exhaust bracket ?? On start up the exhaust can jump a bit .

JC ,

[Pacman1972]

Jonny cobra said:

Hi Have you looked at the rear exhaust bracket ?? On start up the exhaust can jump a bit .

JC ,

I'll take a look - The sound is more of a single thud sometimes followed by a 2nd thud about 20 seconds later.

[adycole]

I also had the same noise happen in mine
on the way to nec last week, was getting low on petrol
so checked the boot at petrol station but couldnt find
anything wrong apart from suction back pressure
from removing the petrol cap.
So i think it must have been the tank making the noise.
It didnt happen again after filling up.

[AlexanderV8]

Someone once told me there is a baffle arrangement inside the fuel tank to help alleviate fuel 'sloshing' around too much on heavy cornering. Apparently these plates have been known to come loose and can move around inside the tank with the consequent 'thud'.

Hasn't happened on mine, so can't confirm the truth, but it sounds feasible.

[darkcat]

probably not much help, but i had a thud from the front on startup, turned out that the engine mounts where shagged, causing the pre-cat to knock on the top chassis rail. might be worth a look, look through the wheel arches.

exhaust mounting would be my next best guess.

[speedtwelve]

Symptoms identical to mine. Occasionally (usually in hot weather), there is a loud thump from the fuel tank a few seconds after engine start, usually after it has been run recently. Normally accompanied by a particularly strained moaning from the otherwise serviceable fuel pump. It's usually a double thump with the second arriving (as mentioned) around 20sec later. Seems to be just pressure equalising in the metal tank and fuel system.

[Bassfiend]

Curse my dirty mind...



Phil

[LordB]

"banging from the back"..... to