2011 C6.5 3.0 Coolant leak

[Mikeythekat]

Somehow it only posted my picture but*I’ve had my 2011 C6.5 for about a year now and it has 97k and some change miles. I had to put coolant in the other day since a nice warning came on to turn off the engine and add coolant. Today looked under the hood and can see a significant puddle of coolant on the belly pan but I cannot tell where it might be coming from. I haven’t had the chance to get underneath to look deeper so I was hoping someone might be able to tell from the picture if there is something that commonly leaks in this area or at least point me in the right direction? I know it’s not the best picture but you can see a puddle in the belly pan. What is the part in the upper circle? That part seems to have some coolant on it and has attracted some dirt so maybe that is leaking? All the hoses and everything below that part looks like it is covered in coolant so I don’t know where to begin. Thanks in advance.

[Big_Reyn]

I experienced that same problem with my 2011 A6 3.0t. My problem was the water pump. I also replaced the thermostat, the cross over tube connecting the heads and I also did my VCG's because they were starting to leak. Check the condition of your belts since they will be removed if it's the water pump.

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[AFONE]

My 2009 has a slow coolant leak as well. Someone posted a few months ago that replacing the reservoir solved there issue. Could be the source of yours as well.


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[Chris@EPL]

If you have a slow leak without any drips or puddles, check your #3 or #6 plug and see how they look. Could be a leaking IC from the SC.

[Mikeythekat]

I experienced that same problem with my 2011 A6 3.0t. My problem was the water pump. I also replaced the thermostat, the cross over tube connecting the heads and I also did my VCG's because they were starting to leak. Check the condition of your belts since they will be removed if it's the water pump.

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Is the part I circled in the top circle the water pump? I've a visual worker so if I have a diagram or schematic it makes more sense. About how much were all the parts?

Thanks

[Mikeythekat]

Thanks for the suggestion. That was actually the first place I looked and nothing in the vicinity of the reservoir has any signs of leaking. It appears to be only leaking from the front of the engine.

[Big_Reyn]

That does look like the water pump, however everything is so tight on our cars it's hard to say definitively. I initially suspected my thermostat was leaking.

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[fawwazlawal]

I had the same issue and I'm currently go thru the process of fixing it. I have a thread and YouTube video on the process. I have plenty info in the video

https://youtu.be/2rWVqA_4_lc

[11A6]

The c6.5 cars had a TSB for replacing the water pump/thermostat which is NOT the item you have circled in red - I think that's the vacuum booster. I believe the water pump/thermostat is lower in the engine and may be under the supercharger?

[Mikeythekat]

I still haven't had the chance to get underneath the car to investigate further. Based on what I've read and your comments I'm leaning towards the water pump leaking. Perhaps that is the problem and coolant has leaked onto the belt which is spraying coolant all over the front of the engine. Can someone give me an idea about what is involved with replacing the water pump? I've been unable to find any videos or detailed instructions about how to do it.

[Big_Reyn]

There are two areas circled in the picture. The smaller circle in the photo appears to be the water pump. The larger circle is the vacuum pump.

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[fawwazlawal]

In this thread I have more info that I think could help diagnose your problem

https://www.audizine.com/forum/showt...4#post13889884

[Mikeythekat]

Does anyone have a parts diagram for the 3.0 engine? I'd like to be able to identify all the parts on the front of the engine.

[B. Rock]

The 3.0t and 3.2 belt replacement guides are probably your best bet for getting a handle on which pulley is which. @Big_reyn is right though - the top circle is your vacuum pump (known for leaking oil, which yours appears to be doing), the bottom circle is closer to your water pump.

The water pump and thermostat are very close together. It'd be hard to detect which one was leaking given the way everything is packaged, however if you replace one you might as well replace the other, since they require the same amount of work to get to.

It's a full day job for DIY if you haven't done it before, possibly more depending on how things go. You'll be pulling the blower and putting the front end into the service position. I took the time to do several other items while I was in there since it's just so much fun to do both of those things and didn't want to be doing it again soon.

[a1dan_87]

I wouldn't be surprised if it's the water pump, it's a common enough problem on our cars. If you're having it done, it may be worth doing the thermostat and possibly PCV (if it hasn't been done) as I believe all three reside in the valley, under the supercharger, and typically fail at some point as well.

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[fawwazlawal]

Does anyone have a parts diagram for the 3.0 engine? I'd like to be able to identify all the parts on the front of the engine.

Literally just click on the link it will lead you to how I fixed the coolant leak issue titled FOOZY Build Sheet
https://www.audizine.com/forum/showt...C6-Build-Sheet

with diagrams and all. I am also working on a video edit on how to actually gain access to it all up front.

[stuffinder]

The top nipple on the water pipe at front of engine is the culprit!

[Mikeythekat]

Is the top nipple on the water pipe the one that the small coolant return hose connects to? If it is, that broke by lightly touching that hose. I did a quick patch with a small hose clamp and that's alright for now but I do think there is another leak on that front crossover pipe because when I squeeze the large soft coolant hose on the drivers side I can hear air leaking somewhere in the center of the engine which sounds like it could be from the crossover pipe also. Any ideas? Since I need to replace the crossover pipe, what seals or o-rings do I need to get to replace it? I'm going to replace the thermostat also since I'll have it apart and have the intake gaskets and new thermostat bolts. Is there anything else I need to get or tips/lessons learned from others doing the same repair?

[B. Rock]

Do the water pump at the same time. It's right there.

If you look on the parts diagrams, there are o-rings on each of the pipe connections. I would *highly* recommend getting one of each of those. Good luck, I had a hell of a time separating the connections. The pipe should come with the o-rings for the connections to the block.

Since the blower came off to do the work, I also did a carbon cleaning, changed the blower oil, and did the PCV (the original reason I was in that area in the first place). I also replaced the coolant pipe that runs under the blower. Not listed as a common failure item, but it seemed odd to me to replace the crossover pipe and not that one (#23 in your diagram)

[c@@kieMonsta]

The top nipple on the water pipe at front of engine is the culprit!

This. I had mine break @ like 60k miles.