Hi guys

can anyone tell me why my old (1997) K74 should idle at 1750 rpm until quite hot then settle down?

It used to idle a little faster until it warmed up but only for a few minutes. Now it's much faster for longer.

there is a fast idle thing on your fuel pump @Alan G knows about them

may have answered my own question

No water in the radiator so presumably the temp sensor was unable to read properly until what water was left in the system boiled around

now got to look for a leak