coolant levels

[jaye944]

So I'm confused, I've seen various bits of info on the web you tube and even the users manual.
so I'm just gonna ask my questions


1> Why is my coolant reservoir cap always a bit loose, despite tightening it up

2> What level should the float be HOT & COLD (I know what the diagram on the res. says)

3> When it says add when cold, is it from 1st thing in the morning? leave a time after running

4> I usually consider a 3 hour standing time as "cold"

5> I use 50/50 BMW coolant

I don't know if I'm loosing coolant, becuase of the hot/cold float thingy !

[jaye944]

that said

last night after leaving the engine for 3 hours I topped up so the float was at maximum
this morning at 5am, checked the level on cold engine, float was at max (cap firm and not moved)
drove 40km hiway to work
left the car for 3 hours and on my break checked the level, at full (float maxium) and the cap firm and shut

[Olgeezer1]

Your reservoir cap sounds normal. 50/50 BMW coolant with distilled water is the way to go. One thing you might try is running your level at the min. mark, that is , the float just even with the top of the reservoir. A tip from an old BMW guy. Gives that plastic expansion tank a bit of a break, lets it do it's job, extending its life and has no effect on operating temps. Oh, and to me, cold means first thing in the morning, these engines hold heat for a long time.

[jaye944]

txs geez !

[ianc]

I've also heard the tip on slightly under filling coolant to reduce stress on the tank.

Definitely wait overnight to check the level. Put the hood up before you go to bed to remind yourself in the morning!

ianc