Unknown coolant leak from rear of engine

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
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Brenrs6
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Unknown coolant leak from rear of engine

Post by Brenrs6 » Mon Sep 18, 2023 9:37 am

Hi everyone I’ve recently was able to get my hand on a 03 rs6 and recently it’s been leaking coolant from the rear of the engine towards the passenger (US) side I can’t seem to see the leak watching it idle but I can see there is a leak as it is running down the pipe I’ll attach some photos I’m pretty mechanically inclined and have already fixed some of the issues the car was having like a bad alternator and such any idea where the leak could be coming from would be great thank you! I was able to get my fiber camera under where I though the leak was coming from but I don’t see any sort of leaks under that pipe as well.
Attachments
IMG_5037.jpeg
Originating leak I believe since it’s the highest point
IMG_5038.jpeg
Fluid down the coolant pipe
IMG_5059.jpeg
Picture from my fiber camera above the drip

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Shoppinit
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Re: Unknown coolant leak from rear of engine

Post by Shoppinit » Mon Sep 18, 2023 11:29 am

There's a steel coolant pipe that goes round the back of the engine, where the temp sender goes into, which is prone to corrosion. You might have a pinhole on there.

Or maybe the temp sender gasket is not sealing properly.

If you take the airbox off, can you see any better? If necessary you can remove the MAFs from the airbox and put them in place to run the engine for a short period.
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

steve2003rs6
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Re: Unknown coolant leak from rear of engine

Post by steve2003rs6 » Wed Sep 20, 2023 1:12 pm

Is it definitely coolant. The ac draining can shed a fair bit of water. When I have been parked up several people have said you have got a water leak.
But it was from the a c unit.

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Shoppinit
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Re: Unknown coolant leak from rear of engine

Post by Shoppinit » Wed Sep 20, 2023 1:19 pm

Who you calling a c-unit?
Daytona RS6 C5 Avant. Viper'd, Billies, Waggers, MTM box brain, C6 stoppers, xcarlink, R8 coolant cap (woohoo)
///M3 E46 | XC90 (V8, natch) | Passat GTE | RR Classic V8 flapper
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair."

steve2003rs6
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Joined: Mon Aug 19, 2019 7:43 pm

Re: Unknown coolant leak from rear of engine

Post by steve2003rs6 » Wed Sep 20, 2023 3:45 pm

Lol.

Brenrs6
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Re: Unknown coolant leak from rear of engine

Post by Brenrs6 » Tue Sep 26, 2023 3:38 am

It’s definitely coolant because I’m filling up the reservoir every couple weeks as it’s going down and I can smell the coolant burning.
Hopefully this weekend I can get around to puking off the air box as that was my next move everything been put on halt for my brothers wedding but I’ll post an update soon thank you guys.

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