help!!! :( glow plug light flashing

[vdubnut]

Hi All

Been driving my 1.9 TDI 1997 down to reading last night..... stopped @ the services.... when leaving started the car as normal the revs went to abou 2000 in a blip then back to normal....after about 30 secs...the glow plug light started flashing.....car running ok so does anyone know whats the next step

Cheers

Andy

[vdubnut]

update : jusy been out with the car cold and the car started just as normal......had found that the brake bulbs can cause the light but theyre woring fine?  Ill need to get the engine hot and see if this returns.... would love to know why it started tho and if its a bigger problem