When to change glow plug?

[Thanos]

Hi all!! I run my car almost 2-3 tanks per week, have it tuned OK and glow plug is nice and shinny with a bit of oil on it. Is there a "time" limit when I should change it with a new one just to be on the safe side? I 've read of the possibility of the tip breaking and falling in the engine... No good I guess..
Thanks
Thanos

 

[atvrider93]

i would just change it when it stops running well and is getting hard to start

 

[Larsenracing]

atvrider is correct. You only need to change it when it's not working correctly.

 

[Thanos]

In other words, the first sign is "hard to start" or indication of major tuning changes??
thanos