Afternoon Folks, I have a 2010 focus zetec 1.6 tdci

When the engine is cold I get the green shift come on to change gear but when I change gear the revs hang quite a lot (pretty annoying and this is any amount of revs after the light pops up), but after my daily motorway journey on normal roads I don't get the green shift come on and when I do change gear the revs drop like I would expect (no hanging) is this right? or should the shift light come on weather the engine is cold or up to temp?.  The revs only hang when im getting the shift light come on...just seems a bit strange or maybe its not

I have noticed that on start up its a bit rough and a bit of smoke comes out of the exhaust and after reading its probably a glow plug or plugs failing.  I have been debating weather I should try to replace these myself as ive read some horror stories about them sheering off, but was wondering if the hanging revs are linked to these failing parts?

Thanks for any comments

Dont just change the glow plugs they only come into play at low temp, get the fault codes read, you can do,it yourself if you have a laptop download Forscan (Free) and get a modified ELM lead from tunnelrat cost about £20 for dealer to read codes  £70-90

22 minutes ago, pragmatix said:

Dont just change the glow plugs they only come into play at low temp, get the fault codes read, you can do,it yourself if you have a laptop download Forscan (Free) and get a modified ELM lead from tunnelrat cost about £20 for dealer to read codes  £70-90

Thanks for your reply pragmatix, I do have forescan and the wireless ELM and there are a few fault codes on there, but I was wondering if the green shift light is the same for everyone else (like hanging revs) and when the engine has warned they no longer get the shift light.

Thanks again

41 minutes ago, Chris001 said:

Thanks for your reply pragmatix, I do have forescan and the wireless ELM and there are a few fault codes on there, but I was wondering if the green shift light is the same for everyone else (like hanging revs) and when the engine has warned they no longer get the shift light.

Thanks again

I never pay any attention to the shift light stopped using it ages ago, 

10 minutes ago, pragmatix said:

I never pay any attention to the shift light stopped using it ages ago, 

tbh I shift when I want to shift but the hanging revs are a real pain but when the shift light does not come on after the car has warmed up the revs don't hang is this normal?