A3 - Add DSG Auxiliary Radiator from S3/Golf R (help)

[jamper]

Hey all,

I'm looking to add the driver side front mounted lower radiator from the S3/Golf R to my 2017 A3 S-Line. Currently I'm getting a parts list together to tackle this project. The parts for the radiator, mounting bracket, and ducting seem to be straightforward. I've compiled a list of the following parts which should complete the mounting of a new radiator and allow air to pass through properly:

1 x Radiator - 5Q0121251HA (Planning to use a CSF DSG Cooler for this)
1 x Radiator Mount Bracket - 5Q0121093BF
1 x Air Duct - 8V3807681AEESM
1 x Air Duct - 8V0121673B
1 x Air Duct - 8V0117339
1 x Protective Grill - 5Q0121557A
1 x Inner Fender Liner - 8V5821171B

Next is connecting to the A3's coolant loop. I'm trying to find out exactly what is needed here to run the system like the S3. I've been looking at diagrams of the A3 and the S3's coolant systems trying to figure out how the connection to the system would work.

Based on this diagram, I've come up with the following parts:

1 x Coolant Hose - 5Q0121051L
1 x Coolant Hose - 5Q0121101P
1 x Hose Bracket -5Q0121093BD
1 x Coolant Hose Adapter - 5Q0122291CJ
4 x Spring Band Clamp - N90687001

There must be more parts needed for the connection but not sure what else is needed. Any feedback would be greatly appreciated!

~James

[Clod]

Any reason you want to do this?

[jamper]

My first DSG blew up after 20k miles so I'm looking to add some additional cooling capacity as the car is driven hard often

[MikTip]

My first DSG blew up after 20k miles so I'm looking to add some additional cooling capacity as the car is driven hard often

Is your A3 tuned? Modified? DSG tuned?

[spacecase]

I looked online and found kits to do this for the GTI. Might be a better place to look there instead of A3 as I can't find much info for A3 even though they're the same platform.

S3/GolfR come with auxiliary DSG coolers and they have the same tranny (DQ250 or DQ381). If this guy is running his car hard I can imagine his oil having temp issues. From what I read adding this auxiliary cooler has helped keep the temperature in check in the upper range (240-270F), but won't help during regular driving as that is set to be maintained at a certain temperature setpoint. Doing some research, it seems this retrofit is beneficial for anyone the has an aggressive tune, bigger turbo, or someone that tracks their car. My thoughts are, it might not help performance too much but if you care about longevity of your car I see no harm in adding additional cooling especially if you increased power.

https://csfrace.com/csf-cooling-rele...-mqb-platform/ Some reading I did about this.

[EROtero]

If you drive hard enough to get your trans oil temps above 260 then the OEM aux coolers are not going to be much help. Go with something like this ICECAP or this RacingLine DSG Kit for the trans oil. And for the engine oil side get this RacingLine Oil Cooler Kit. But I do suggest upgrading the oil cooler core to a larger 19 row single pass or a 10 row dual pass from Mishimoto. And don't forget thermostat bypass.

This is the setup I have and has been flawless. It was also both cheaper than installing all the hem S3/GolfR parts and easier to instal.

[jamper]

Is your A3 tuned? Modified? DSG tuned?

Yes it is APR Stage 2 ECU & APR DSG tune. Pretty highly modified, I just updated my signature with some of the mods

I looked online and found kits to do this for the GTI. Might be a better place to look there instead of A3 as I can't find much info for A3 even though they're the same platform.

S3/GolfR come with auxiliary DSG coolers and they have the same tranny (DQ250 or DQ381). If this guy is running his car hard I can imagine his oil having temp issues. From what I read adding this auxiliary cooler has helped keep the temperature in check in the upper range (240-270F), but won't help during regular driving as that is set to be maintained at a certain temperature setpoint. Doing some research, it seems this retrofit is beneficial for anyone the has an aggressive tune, bigger turbo, or someone that tracks their car. My thoughts are, it might not help performance too much but if you care about longevity of your car I see no harm in adding additional cooling especially if you increased power.

https://csfrace.com/csf-cooling-rele...-mqb-platform/ Some reading I did about this.

Thanks for the info and link, spacecase! My main concern is keeping temps down as well as extending the longevity of the transmission. I've been looking for info on GTI/A3 forums and Google but haven't been able to find anything with the details I need yet. The search continues!

If you drive hard enough to get your trans oil temps above 260 then the OEM aux coolers are not going to be much help. Go with something like this ICECAP or this RacingLine DSG Kit for the trans oil. And for the engine oil side get this RacingLine Oil Cooler Kit. But I do suggest upgrading the oil cooler core to a larger 19 row single pass or a 10 row dual pass from Mishimoto. And don't forget thermostat bypass.

This is the setup I have and has been flawless. It was also both cheaper than installing all the hem S3/GolfR parts and easier to instal.

Thanks for the reply, EROtero! Lots of good info here! I've been looking at the sandwich plate option, too. Does the sandwich plate run coolant through it or the transmission oil? If it's the oil, how do you empty the oil from it when it's time for a trans service?

The DSG ICECAP's have been out of stock/unavailable for a while now. In April 2020, I contacted Scott from USRT asking when the DSG ICECAP would be back in stock. He let me know that they are working on a new revision that has a thermostat integrated into the adapter plate. The bypassing and such will be done internally. So, you'd just run the lines to/from heat exchanger and "done". Sadly there is no timeline for it yet.

Thanks for the tips about the RacingLine kits! I've had my eyes on these as well but it's hard to justify the price when reading that the coolers need to be upgraded for it to perform properly. Regarding adding a thermostat bypass to the RacingLine kit, I've heard that the sandwich plate has a built-in thermostat in the form of a pressure control valve which only allows the oil to pass through once it's reached a certain temperature/viscosity. I'm not sure if that's correct though, so someone please feel free to chime in!

[EROtero]

Jamper, I have a new spare complete DSG kit with IceCap, hoses, fittings, thermostat, and 19row cooler if you are interested in it. PM me and I will send you some photos. I'll give you a good deal on it.

[mroberte]

Why not go with the aftermarket dsg oil cooler from vwr? It will directly cool the oil with a built in thermostat too instead of passively cooling like the oem does?

I have an aftermarket oil cooler on the engine and it has helped, but have yet to setup my aftermarket dsg one using a icecap type plate.

Sent from my Pixel 3 XL using Tapatalk

[jamper]

Jamper, I have a new spare complete DSG kit with IceCap, hoses, fittings, thermostat, and 19row cooler if you are interested in it. PM me and I will send you some photos. I'll give you a good deal on it.

Thank you! PM'd!

Why not go with the aftermarket dsg oil cooler from vwr? It will directly cool the oil with a built in thermostat too instead of passively cooling like the oem does?

I have an aftermarket oil cooler on the engine and it has helped, but have yet to setup my aftermarket dsg one using a icecap type plate.

Sent from my Pixel 3 XL using Tapatalk

I'd like to keep an OEM water/air cooler as it will help the oil come up to temp as it's warmed by the coolant.

[mroberte]

Thank you! PM'd!



I'd like to keep an OEM water/air cooler as it will help the oil come up to temp as it's warmed by the coolant.

There is a thermostat so you don't need to worry about this

Sent from my Pixel 3 XL using Tapatalk

[EROtero]

Replied!

[ElCheapoA3]

Bump!
Did you ever finish the project? Does the Aux cooler plumb into the same position as the basic DSG water/oil heat exchanger?

[949]

im doing the csf side radiator upgrade as well. there are two side tho. i forgot what the other side is for but they all use the coolant from the radiator.