What is fan after run mode ?

[2010 Bumblebee]

What is fan after run mode ?

Is it fan time after the fan runs or fan time after the car is turned off?

So what would I do If I want my fans to cool my car down to a certain temp after I turn the car off and park it? (L99 camaro ss)

[Happy Jim]

Yes, it's a timer for how long to leave on.

The only way to really get the water temp down would be to install an electric water pump and have that run on as well.

I set mine for 90 seconds - no scientific thought behind the duration though :angel_innocent:

Jim

[2010 Bumblebee]

But Jim, is that a timer for how long it stays on after you turn off the car, or a timer for a cycle when the car is running.

[joecar]

My understanding:
after run mode = engine was just shut off and ECM is in "after run mode" (ECM is not shut off yet).

[joecar]

In run mode (ECM is operating the engine), the fans are turned on when ECT reaches/exceeds (going up) the "Upper" temp, and will continue to run until ECT reaches/exceeds (going down) the "Lower" temp... i.e. no time is involved (strictly temperature/hysteresis controlled).

[2010 Bumblebee]

Ok,

We have the following settings;

fan after hi temp uppper 266 ºF
fan after hi temp lower 262.4 ºF
fan after run temp upper 235 ºF
fan after run temp lower 233.6 ºF
fan after run max time 30.0 (in seconds)

So I'm guessing after I turn off the car for 30 seconds the fan will run if the coolant temp is between 266 ºF - 233.6 ºF, and it will run at high speed between 266 ºF 262.4 ºF , at a lower speed between 235ºF-233.6ºF, correct?

These are only after the car is turn off and don't overide the regular fan setting right ?

Aren't these number kind of hi and the fan after run kind of short ?

Also basically the fans will never run after the car is off with these settings because the car never operates that high, right?

Anyone know what the seconds limit is ? If I put 600 will it run for ten min?

Also, My operating range is between 188ºF-206ºF if I'm correct.

So if I want to cool my car down quicker while parked can't I change the "fan after hi temp lower" to 228ºF AND "fan after run temp lower" to 188ºF and the time to 600? If I want to?

[joecar]

My understanding:

- if ECT goes to or above 235ºF, fan low speed on.
- if ECT goes below 233.6ºF, fan low speed off, after fan has been running for 30 seconds *.

- if ECT goes to or above 266ºF, fan high speed on.
- if ECT goes below 262.4ºF, fan high speed off.

Yes, those temps are all quite high, if after run is active then something's gone very wrong with the motor.

EFILive tunetool shows the min and max values in the upper right... it seems to me the max is 240 seconds.

Yes your engine's operating range is about that.

Doing that will cool the coolant in the radiator but since the coolant pump is stationary the cooled coolant may not flow into the engine... and watch the battery, this is a significant load on the battery.

(their descriptions are not vary clear)

[2010 Bumblebee]

Very interesting observations and good point about the battery.

But I think it could handle 240 (4 min) with he fan on high and the radio running if you have not exited the car for the 10 min max without a problem in warm weather. In cold weather I don't think this cooling down would even be an issue.

It just would be nice to park the car somewhere, like say a dragway, and have the car cool down a little quicker between runs.

[joecar]

The fans will keep running until the lower temperature is reached, and will keep running if it the run time was below the run time parameter.

[2010 Bumblebee]

The fans will keep running until the lower temperature is reached, and will keep running if it the run time was below the run time parameter.

I was just thinking about this. I would only want to change the "fan after hi temp lower" and the "fan after temp lower" because if I change the upper values the fans wouldn't come on if the temp was beyond that value, correct?

You are saying once a fan hi mode is triggered it will set the fan on hi until the timer runs out or will they stay on hi or go into low mode after the values change?

Can the fan after run hi temp lower and fan after run temp upper overlap?

[joecar]

Yes, the lo speed upper temp has to be lower than the hi speed upper temp, otherwise like you said it will inhibit the lo speed fan.

And also:
- the lo speed lower temp has to be lower than the lo speed upper temp.
- the hi speed lower temp has to be lower than the hi speed upper temp.

Once hi speed mode is triggered, it will stay in hi speed mode until temp drops below the hi speed lower temp, and then it will be in lo speed mode...

and then, while in lo speed mode, when the temp drops below lo speed lower temp, the fan will stop if the total run time has exceeded the run time parameter.

Yes, the hi speed lower temp and lo speed upper temp can overlap, that is ok.

[2010 Bumblebee]

This is a cool feature. I wonder why it's not in use. I guess people would not want to hear their fans going after they get out of the car, but it could be useful to bring down the engine temp a little quicker while parked at the track .

[joecar]

In the above discussion, here's what I'm not sure about:

fan after run max time

I'm not sure if this is the maximum run on time regardless of upper/lower temps, or if this is the minimum run on time (as I indicated in my posts above).

I just went and looked in an LS1 file and I saw both minimum and maximum run on times, but only the run on upper temp (i.e. no run on lower temp).

The E38/E67 descriptions are a bit vague/incomplete...

[joecar]

Problem with fan run on is that the coolant pump is stationary... maybe hot/cold convection flow pushes coolant around, but the coolant has to go past the pump impeller to get into the block, which it can't do if the impeller is stationary.

:)