Aux Water Pump

[BuffaloRS6]

Hey guys. Noticed my coolant was low last week so I added some G12 and thought nothing of it. Today I came home from work for lunch and when I came back outside I noticed a large puddle underneath my car. I started the car and backed up to take a closer look and it was def coolant. Immediately called my mechanic and he asked me to bring it in (his shop is relatively close to my house). I drove very carefully and watched the gauges like a hawk. No change in temp readings whatsoever. Once on the lift and pressure tested, coolant began leaking again. It seems to be coming from below the intake but in the front of the motor. Pricing on a pump is $400+ from the dealer. I'm holding off on ordering it though because I'm hoping that's not the issue but I assume it is the pump. Basically what I'm getting at is, has anyone had this issue? Is there anything else I should do while the front end is open? I'm @ 86k miles and had the timing belt done @ 75k as recommended. It figures that I finally sold my S4 YESTERDAY and now this. Ugh. The joys of Audi ownership. Any input would be appreciated. Thanks guys.

[ttboost]

Is it coming from the left side? Right Side? Center? Maybe one of the coolant lines isn't tight, as you were just in there a little while ago...?

[BuffaloRS6]

It's leaking from the middle, a little bit towards the passenger side. I'm really hoping it's just loose coolant line, but with my luck it'll be the pump. Doesn't really matter though; I'm still looking @ roughly 6-8 hours in labor & possibly a $400+ part, right?

[lswing]

I'm still looking @ roughly 6-8 hours in labor & possibly a $400+ part, right?

...said everytime I go to the shop. Hope it's an easy fix!

[ttboost]

Maybe not..I wouldn't get all worked up into frenzy until you poke around a little...maybe..hopefully, something stupid and easy...

[Elevens]

Be prepared for the worse. That Auxillary water pump is usually the Culprit...............

[G2]

It's leaking from the middle, a little bit towards the passenger side. I'm really hoping it's just loose coolant line, but with my luck it'll be the pump. Doesn't really matter though; I'm still looking @ roughly 6-8 hours in labor & possibly a $400+ part, right?

Sounds familiar--- Last 2 I saw at our shop, to include an S8 with the 4.2, was the water pump leaking. The bearing was also fairly loose-- not good. There's NO reason to spend $400 on the WP. We get and sell excellent German made pumps with cast metal impellors for less than 1/2 that. And we upgrade the gasket to a Victor Reinz, also German made. We do not EVER use the supplied gasket-- even tho' the German made pumps have decent gaskets. We also add add'l ultra high grade sealant when installing the pump. A paper gasket is not adequate in our opinion, nor does it accommodate for corrosion that is often removed when the old pump is replaced.

If the T-belt was recetly replaced and the w/p was not, then it's safe to assume neither were the tensioner or idler rollers. Everything should be replaced, even the cam and/or crank seals-- especially for a 10 year old vehicle.... For the RS6 we like to use the Gates Racing Timing belt, which is not too spendy but far stronger than OE. It's either that or pulling the heads to replace a bunch of valves when things fail. I have an excellent race guy that can port the heads, however....

[ttboost]

I would confirm with whoever did the timing belt service, to see if they did the WP, rollers, etc, that is SUPPOSED to be done at the same time. If they charged you for a "full service" and only did the timing belt, that car should be leaking in their parking lot, and you shouldn't be paying anything ....Good Luck.

[SteveKen]

When the valley fills with coolant due to the affterrun pump leaking (slowly at least) I've only seen it leaking from the rear of the engine. Could be a hose. I hope.

[BuffaloRS6]

Everything was properly done by the shop when they did the timing belt. On that note, I have some good news. It's not the aux pump. It's the valley pan gasket that's the culprit. I'm VERY relieved and hopefully looking forward to getting my car back on Monday sometime. Is the OEM gasket a good replacement or should I look for an aftermarket gasket that's a little stronger? I have some pictures I'll post up later when I get home. Anything else in there I should be considering while it's open? Def getting an oil change while it's in there.

[SteveKen]

Everything was properly done by the shop when they did the timing belt. On that note, I have some good news. It's not the aux pump. It's the valley pan gasket that's the culprit. I'm VERY relieved and hopefully looking forward to getting my car back on Monday sometime. Is the OEM gasket a good replacement or should I look for an aftermarket gasket that's a little stronger? I have some pictures I'll post up later when I get home. Anything else in there I should be considering while it's open? Def getting an oil change while it's in there.

I can't imagine that would ever go bad. Strange though and am interested in seeing pictures. I'm wondering if you can get coolant in the oil or vice-versa with this type of failure?

Your car is at Jason's shop, I assume?

[Elevens]

Not really sure what the Valley Pan Gasket is, but glad it's not your pump. That pump is usually prone to failure. It failed on my past A6 2.7T. Good luck with the repair...................

[lswing]

Valley pan gasket is what?...never heard of this in years, info please...

[BuffaloRS6]

137191372013721

[alrightroad]

https://lh5.googleusercontent.com/-g9wXLxzOzYg/UWBkSyQJ0AI/AAAAAAAABkM/Z_jYDSZjrFE/s800/IMG_04451.1.jpg

[BuffaloRS6]

https://lh5.googleusercontent.com/-g9wXLxzOzYg/UWBkSyQJ0AI/AAAAAAAABkM/Z_jYDSZjrFE/s800/IMG_04451.1.jpg

Yes. This.

[Elevens]

Looks like a bitch to get to, to replace it..........................

[905084]

Passenger side front = oil cooler pipe.

[BuffaloRS6]

Passenger side front = oil cooler pipe.

You're saying it's the oil cooler pipe that's leaking?

[BuffaloRS6]

Looks like a bitch to get to, to replace it..........................

Yeah, man. Total bitch to get to to replace it. I'm glad it wasn't the pump though. I still can't believe the amount of work it takes to do the simplest things in these cars. haha

[905084]

You're saying it's the oil cooler pipe that's leaking?

If your leak is on the passengers side, towards the front (i.e. around the right front motor mount) it is the oil cooler pipe. This is a high failure item on the 4.2 V8 (not particular to the RS as I have done both of my A6 4.2's). The aux pump mounts on the drivers side "frame" rail and runs coolant to the turbos underneath the intake.

[BuffaloRS6]

Thanks. I'll relay that to my mechanic and have them check it out.

[905084]

If that's what it is, use the Bufkin pipe on eBay, not the Audi one.

[BuffaloRS6]

Well the car is being put back together today. I'm glad it wasn't the aux pump that was leaking, however, the valley pan gasket was still a $155 part. Haha! Nothing easy about this car. Seems the simplest task can take 6-8 hours of labor. Bottom line: we're all crazy for owning one of these things, but I still love it!

[kday]

Doesn't the valley pan gasket seal the top of the crankcase? How does it cause a coolant leak?

I have never seen the valley pan of the V8, but on the V6 when it leaks, it leaks oil.

Personally I'd much rather do a water pump than a valley pan gasket...

[905084]

Valley pan gasket?? I remember doing one of those on a 1968 Buick....didn't order one for my rebuild.....maybe I should check...

[mdegracia]

Definitely seems odd that you'd get a coolant leak and not an oil leak from that gaske,t if it were faulty.

Did they at least replace the after-run pump while they were in there? If, not, I'd be curious to see if the leak returns.