Cooling turbos - Afterun pump ?

Post by **Nige_RS4** » Thu Aug 18, 2005 2:32 pm

Finally did this mod as I had a week off work, and yes i can now hear the fan running

It took a week to do a 10 minute DIY job ???

Do you charge yourself by the hour or something?

Post by **CliveH** » Thu Aug 18, 2005 3:45 pm

Nice one Simon! I hope you didnt make the mess of it that I did!!!

It's a very effective mod (and could do it with my eyes closed now!)

Post by **SimonS4MTM** » Fri Aug 19, 2005 11:12 am

It took about six weeks if you include the time since i bought the parts.

Post by **Morpheous** » Wed Aug 31, 2005 10:06 am

I have one of these thermo switches for sale on ebay at the mo, along with other S4 goodies

Post by **Nige_RS4** » Wed Aug 31, 2005 10:16 am

Well tell us your Ebay username / or post a link to your goodies please ....

Post by **QuantumJohn** » Wed Aug 31, 2005 11:03 am

Here is the list of items on ebay

http://search.ebay.co.uk/_W0QQsassZwngcdrbader

Simon,
Did the porsche brakes go with car?

Cheers,
John
P.S. your old RS6 wheels fit great.

Post by **Morpheous** » Wed Aug 31, 2005 11:07 am

Yes John they did. But I have the S4 calipers up for grabs on ebay if you still have the car you came round in.

Thanks for posting the link, never sure how these forum tools work.

Post by **dummi** » Mon Jan 30, 2006 12:03 pm

very good i will be doing this!

Post by **searider** » Mon Jan 30, 2006 12:15 pm

Hi Chaps

Was reading through the 2.7T study guide the other night - can't remember where I downloaded it from - the guide describes the operation of the engine and its systems and appears to be an Audi publication produced for their mechanics.

This pump reverses the water flow and will therefore only run if the engine is not running. If the engine is not running oil will not be circulating through the turbo bearings. Therefore whatever oil is in there will get cooked just as before?
Correct me if i'm wrong but I don't believe that the turbos are water cooled in any case?

Surely what needs to be done is to cool the turbo from 1000C before switching off rather than reducing the water temperature by a few degrees?

Isn't a turbo timer what's really required.

Still, looks like a cheap mod and can't do any harm.

Duncan

Post by **Dippy** » Mon Jan 30, 2006 1:23 pm

As you read in the guide, the purpose of the pump is to remove air bubbles which may form when the coolant is very hot. The reverse pump action is to take such bubbles away from the turbos and disperse them in the heads.

The afterrun pump mod (either by changing the sensor or by overriding with a turbo timer), is specifically as an alternative to keeping the engine running with a turbo timer. As you point out, the turbos are water cooled, so keeping the pump going will cool the turbos and prevent cooking the oil.

Now as to if it is better to keep the engine running is a moot point. Yes this would keep the oil flowing, however since the engine is still running, it is also feeding heat into the turbos.

However another factor is what people prefer, or rather don't. Most people don't really want to have their engine idling for 5 mins at the end of the journey, preventing the alarm being set. The afterrun pump mod is convenient on more ways than one.

Post by **UKS4APR1** » Tue Jan 31, 2006 12:18 am

searider wrote: Correct me if i'm wrong but I don't believe that the turbos are water cooled in any case?

Surely what needs to be done is to cool the turbo from 1000C before switching off rather than reducing the water temperature by a few degrees?

The turbos are water cooled and cooling them down from 1000C is just what the water is trying to do !! This in turn helps reduce the heat build-up and heatsoak into the oil.
Also the elecric fans run at a low level to disperse the heat via the radiator.

WELL SAID DIPPY!!
The system is already on your car whether you like it or not, may as well utilize it. Without the mod it rarely comes on.

Post by **paul20v** » Sat Jun 09, 2007 9:01 pm

done mod works great wish i had read this post before thanks to all

Post by **AdamS4** » Thu Jul 12, 2007 3:07 pm

I see Vag-com sell as a kit now.... https://sslrelay.com/s74326199.oneandon ... FTERmod=29

Gonna order me one

Post by **UKS4APR1** » Fri Jul 13, 2007 12:27 am

Think you mean Vagparts !!
VAG-COM is something else.

Post by **AdamS4** » Fri Jul 13, 2007 7:08 am

Yeah, ooppss, my bad, had Vag-Com on my mind yesterday.... its my new gadget

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Cooling turbos - Afterun pump ?

Not sure of the value of this mod to protect turbos

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