Orange leds on rev counter - The Unofficial BMW M5 Messageboard (m5board.com)

Envisage0 · 3rd May 2007, 09:05

I recall a discussion about the advisory orange leds on the rev counter and whether they were governed by the oil or the coolant temperature. It seemed that the consensus was coolant-governed.

However, before I changed my oil this week, there was only one segment lit but immediately after refilling they were all lit. This suggests they are oil-governed...........or does it?

richie_rvf · 3rd May 2007, 10:34

Maybe in the time it took to carry out the oil change the coolant temperature had dropped sufficiently to illuminate the rest of them?

Richie.

Envisage0 · 3rd May 2007, 12:52

Quote:

Originally Posted by richie_rvf

Maybe in the time it took to carry out the oil change the coolant temperature had dropped sufficiently to illuminate the rest of them?

Richie.

It normally takes more than an hour for that to happen Richie. The oil change took 15 minutes.

richie_rvf · 3rd May 2007, 12:55

Mmmm, maybe it is linked to the oil also then - I don't know to be honest

Richie.

athM5 · 3rd May 2007, 14:09

Personally, my LED's go out at about the same rate as my oil temp goes up. So for me, they are related.

alantd · 3rd May 2007, 15:12

I think it is coolant-related. Mine seem to follow water temperature more closely than oil temp.

I wonder whether just having the bonnet open for the time it took you to change the oil sped up the cooling.

Envisage0 · 3rd May 2007, 15:48

Quote:

Originally Posted by alantd

I think it is coolant-related. Mine seem to follow water temperature more closely than oil temp.

I wonder whether just having the bonnet open for the time it took you to change the oil sped up the cooling.

Good point......

Somebody must know the definitive answer to this thing. It presents itself to all of us every time we start the beast.

ard · 3rd May 2007, 16:56

1. Pouring cool oil into the engine will cool the hot coolant too.

2, Unlock the OBD display (ie like you're doing the MAF tests) and monitor Koolant temp and/or OelTemp... report back!

A

E55AMG2 · 3rd May 2007, 17:07

It's coolant based in my experience, once the Ktmp hits 80C the orange lights all (except for the last one) go out.

Envisage0 · 3rd May 2007, 17:15

Quote:

Originally Posted by ard

1. Pouring cool oil into the engine will cool the hot coolant too.

2, Unlock the OBD display (ie like you're doing the MAF tests) and monitor Koolant temp and/or OelTemp... report back!

A

Thanks Ard.

Unfortunately my pixels are so bad (2000 model) that I don't know if I will learn much from doing this.

I felt that the time lag between dropping old oil and adding new was so short that it was impossible for the coolant to reduce in temperature to the point that all leds lit up again. I deduced that the oil temperature has dropped sufficiently to cause this.

I suppose this is all a bit anal, but I'm just interested.

Maybe somebody with a solid set of pixels can report back when they (or their mechanic) do an oil change??

gobuffs · 3rd May 2007, 18:16

Definitely oil temp based. Final answer.

E55AMG2 · 3rd May 2007, 18:24

Quote:

Originally Posted by gobuffs

Definitely oil temp based. Final answer.

how do you explain all the segments being off when the oil temp is at 150F?

yblocgerg · 3rd May 2007, 18:26

I think its oil temp related too. I pay attention to the lights, but wait for the oil temp to hit the first circle before

Read that in a post a while back, makes good sense to me.

E55AMG2 · 3rd May 2007, 18:44

The warning lights go out when the coolant temp goes past the first circle. The oil temp is usually still too low to rev past 4k. It also depends on which oil you're running. 10-60 takes more time to heat up than 5-30