Turbo cooling on an RS2

[Veg]

Another question from the man who seems to be demolishing his car!

Anyway I see the ABY kit for the coolant pipes has the 160mm by 12mm (?) pipe included which tucks up under the inlet manifold and provides water to the turbo. My RS2 doesn't have one is this normal

[Rusty]

If it's a stock RS2 turbo, then the oil and water are identical to the stock S2 setup. Have you got a picture of the area described or of the water manifold (which should have a take-off at the front for this pipe).

[UrS4boy]

My RS2 doesn't have one is this normal

These diagrams and PNs, although it says "AAN", applies pretty much equally to the ABY in the S2 and the ADU in the RS2:





Here is part of the RS2 K24-7200 PN listing (same diagram):



More K24-7000 (AAN and ABY) and K24-7200 (RS2) info here:

http://forums.quattroworld.com/s4s6/msgs/211339.phtml

[Rusty]

I think he's referring to the bit on the water manifold, so picture 2.

[UrS4boy]

K24-7000 and K24-7200 Turbo Coolant Lines

I think he's referring to the bit on the water manifold, so picture 2.

I am sure he is. I just want to point out that the RS2 should have the same lines as the AAN and ABY.

Our K24-7000 (or K24-7200, if your RS2'd) turbos have both turbo coolant and oil lines. There is a coolant feed and return line as well as a oil feed and return line (4 lines in total are attached to the turbo)

These four lines (Items 12, 18, 23 and 25) are shown in this parts diagram:



Here are some annotated photos with the exhaust manifold and turbo removed so you can better see these four lines:

Bigger picture:



Close up of the coolant feed line "Union"



In some cases, e.g. removing the turbo or removing the head with the EM and turbo still on, it is easier to remove the coolant feed line at the union, perhaps squeezing the spring clamp from above (and maybe below)(see photo below). If somebody has replaced the spring clamp with a gear clamp it might be easier to just remove the coolant feed line from the turbo.



The return line goes from the turbo to the water manifold under the intake manifold via a pipe (item 25) that crosses the front of the block, behind the cam belt, and then a piece of hose (item 27) that is clamped to the pipe and a banjo fitting (item 26) on the water manifold, as shown behind the after-run switch in the diagram below:



Here is another view (with the head off):


When replacing the item 27 hose, you need to get the exactly correct hose, the one that looks like this:



NOT the one that Audi might send you because the parts guy in the warehouse (not usually stocked locally) is smoking something for "medicinal purposes", like this (note the PN on the bag is correct, but the hose is some soft heater hose):



Replacing the proper hose, try to do it without removing the banjo fitting (just remove the hose from the banjo fitting, even if it is a Beotch). Trying to get the banjo fitting tight under the intake manifold is a bigger Beotch, so try to avoid it.

The oil lines are fairly straight forward. Note that they should get new gaskets when being re-installed after a turbo removal/replacement.

[Veg]

Thanks and it is the beotch pipe mentioned last in the above I can't see. Maybe I should just open my eyes!

[Veg]

Right that 160mm turbo coolant return pipe that sweeps rewards isn't there. However from the banjo fitting there is one that goes forward and is 60mm long instead! A true voyage of discovery!

On another tack the different RS2 coolant hose is the one from the expansion tank that splices into the hose that enters the thermostat (seen on the above photos). This forms one hose rather than having the short thermostat housing one and the long hose from the expansion tank to the base of radiator. Does anyone know why they did this (cavitation issues or some such?) .

The reason I ask is that the S2 coolant hose kit will still fit but will it perform as well?

[Ross]

Can you attach a picture? You are talking about the hose from the banjo under the water manifold, that points toward the front of the engine, and joins the hardline that then runs behind the rear cam cover, out the other side and into the top of the turbo... right? And you're running stock turbo and lines?

I must admit I never noticed any difference between the S2 and RS2 coolant hoses. I have Samco's on my RS2 so I guess it was just the same as my old S2 so nothing for me to notice... certainly not had issues with it but would be interesting to know why it was changed.

[Veg]

Ross

Yes that's the one but on the pictures provided by URS4boy you can see the pipe going to the rear of the engine passed the electrical take offs on the water manifold.

That different RS2 pipe is the one attached. I could easily make the S2 kit fit but there must be a reason why the expansion tank was fed to the engine side of the thermostat rather than the to the radiator. I'm stumped

[UrS4boy]

The hose you are showing has nothing to do with the turbo:

[Veg]

Correct they're the coolant hoses. Two conversations going on!