Temperature light flashing

Hi on the drive in to work this morning I thought I'd take the golf, mistake!
Every speed bump I go over causes the temp light to flash for a couple of seconds it also now does it when I change up from first gear every time I depress the clutch. And when coasting up to traffic. It also judders when this happens and quite a few times cut out. Is it an earth fault or anything more sinister?
Please help!
Thanks

Could be the earth wire from the rocker cover has broken

Would that cause it to flash permanently though? Although it could just be on the way out and the bumps and lumps are creating a break?

Right I believe the problem has been sorted, after tracing the cables there was indeed a pretty poor connection on the rocker cover earth lead but also a lot of the connectors (the connections to the battery terminals were quite loose too) were in pretty poor shape too so once all cleaned and reconnected the problem seems to have gone away. Thanks lhasadreams as even if it was a mixture of the things the earthing cables is something I would not have checked.

No worries - glad to of pointed you in the right direction !!