does anybody have the REST feature in their E55?...when i was at the strip, i wanted to use the REST feature between runs (did this in my s class) to help keep the engine temp down. my 05 doesn't have it

john

 

I have the rest feature in my E55. I use it to keep the interior toasty when I park the car at night and plan to go back out to it. Even if it is parked for hours, at least inside is a bit warmer than if I hadn't used it.

-s-

 

Care to explain this REST feature???

 

When parked (with the engine off, I believe) some features are left on to circulate and keep the inside of the car cool for about 20-30 minutes.

 

Actually, the feature is only there to warm the car. There is a small electric coolant pump that keeps circulating the coolant through the heater core and the motor after you park and you shut off the engine. When you hit the button, the pump is activated for an hour (I think an hour), or until battery voltage drops too far, and the blower is of course active as well. I thought that went away in the W211.

 

You can search the W211 forums for a thread. The REST feature was a victim of decontenting.

 

I have it, use it only when im leaving for half an hour and want to keep my car warm... does it really can help to cool down the engine onthe drag strip between the runs?

 

oh...okay...my car does that too. I can hear all these lil electrical things going off when i turn off my car and wait next it for a minute or two...

 

You have to turn it on, it doesn't come on by itself. Look for the word REST on your heater / air cond panel.

 

Early '05's have the REST feature - at least my former July 2004 build did. My current December 2005 build does not have the REST feature, sad to say. It was one of the running changes for '05's, along with the center console, metal pedals, etc.

 

I have it and have also thought about the cooling effect at the track. I wasn't sure whether or not the heat of the pump/fan running would outweigh the heat being removed from the engine core (since I am absolutely the least mechanically inclinded person on this board, I hope that made sense).

 

From what I hear, the REST feature uses existing engine heat to either warm or cool the car depending on the temperature you set. It uses the same method that the vehicle would employ if you were to turn the key to the position right before start and then turn on the A/C. Although not as effective, the A/C still works when the car is off. So, when you leave, you remove your key and set the REST temperature to whatever you desire. The car, in turn, either uses engine heat or the method that FAST55 suggested to keep the car warm or cool, depending. I've used it for high and low temps and it has worked pretty well for both.

 

I ran the heat on full tilt between runs but did not notice any drop in temperature. With the Z06, we used to run the A/C as cold as possible with the recirculating fan on. Doing that would drop the coolant temps by 10 degrees easilly.