lcc014

I would like to know how the feature "Residue heat" work in our E60 ? Which model year of our E60 has/have this feature ?

Thanks,

crash2646

My 05 545i Sport has this feature... i live in Texas so this is used about once a year. I believe "manual says the engine has to be at operating temp, full battery voltage, and within 15 min of turning off engine." This uses the heat generated by the engine to heat the cabin for short periods of time (~15min) when the car is off. (EX. running into the store..)

lcc014

Thanks for the prompt response. Does this feature has anything to do with the water pump in our E60 ? As far as I know, E60 water pump is driven by the accessories belt. So it runs when engine is running to circulate the coolant within engine and radiator.

Thanks,

vkhong

The first year E60 had "Residual Heat" for 2004. The previous-gen E39 5-series has it too. This mode uses the blower fan only. The water pump is not utilized. From the owner's manual, "Residual heat mode".

Residual heat

The heat stored in the engine is used to heat the passenger compartment, e.g. while stopped at a school to pick up a child.

The function can be switched on when the following conditions are met:
- up to 15 minutes after switching off the engine
- with engine at operating temperature
- with sufficient battery voltage
- at an outside temperature below 77F / 25C

The LED lights up when the function is switched on.
From radio readiness the interior temperature, the air volume and the air distribution can be set.

lcc014

Does it mean that later year of E60 utilize water pump to circulate the coolant to provide the residue heat? I saw posts in other bimmer forums talking about water pump in BMW is electrical versus mechanical for residue heat purpose.

Thanks,

kreveta

https://5series.net/forums/topic/106...warm-interior/

lcc014

Thanks for the link. However, that link does not explain how the residue heat work - using water pump to circulate coolant or not.

Gilgorm

The only noise is the blower motor. Near the end of the 15 minute timeframe, the "warm" air becomes cooler and cooler so the water pump can not be involved. Use of the water pump would suck even more life out of the battery.

lcc014

In other word, warm air is coming from the coolant inside heater core only; not radiator or engine block. Am I correct ?

Thanks,

Gilgorm

I believe yes, otherwise there would be more heat available.