C5 RS6 Coolant Slowly Escaping

[Knowa]

Hi All,

I really hope this isnt going to be a big issue. But I have been noticing that the coolant has started to drop in my RS6, but very slowly... it is roughly a Liter for every 1000 miles driven.

Looking for the leak is proving really difficult. has anyone had this before?

[lswing]

Aux radiators by the intercoolers leaked for me. Nothing is exactly easy:) Pull belly pan and look around...

[Knowa]

Thanks man, Ill take Belly out this weekend. see what I can find.

They should have put 4 cylinders and a turbo in the front, then the other 4 cylinders and turbo in the back... make some room for hands.

[TMAC]

Thanks man, Ill take Belly out this weekend. see what I can find.

They should have put 4 cylinders and a turbo in the front, then the other 4 cylinders and turbo in the back... make some room for hands.

Wouldn't that be nice!!!

[RSoverAll]

.... Nothing is exactly easy:)....

So true with these cars, comparatively speaking

[fbatwork]

My slow leak was the after run pump under intake manifold....

[Bigglezworth]

Looking for the leak is proving really difficult. has anyone had this before?Need confirmation of exact location below your car on where puddle of coolant forms. Aside from a catostrophic head gasket failure, there are only so many locations coolant will leak.

1. Aux rads located in front of each wheel
2. Radiator - front clip
3. Coolant return pipe on back of heads - will drip fluid just behind drive axles either side.
4. Turbo lines - will drip fluid just behind drive axles either side.
6. Temperature sensor - will drip fluid just behind drivers side axle. Easy to see from above.
7. Recir pump located on u/x of drivers side frame rail.
8. Heater core - would smell coolant inside car
9. Overflow tank - will drip fluid in to firewall area
10 After run pump under intake manifold - coolant will be hard to see coming here and make it's way either towards the front of the engine or rear and not produce consistent puddles (and possible two at the same time).

Hoses should all be pretty obvious to tell if leaking. Some items are moderately straight forward to repair, while others are extremely difficult to near impossible without significant mechanical undertaking. Post your findings.

[Dmb408]

fbat, did you replace the suction jet pump while you were down there? Might as well.

[fbatwork]

I did. Replace a ton while it was apart. Spent more than I wanted on parts but didn't want it to haunt me a year later.

[Knowa]

Need confirmation of exact location below your car on where puddle of coolant forms. Aside from a catostrophic head gasket failure, there are only so many locations coolant will leak.

1. Aux rads located in front of each wheel
2. Radiator - front clip
3. Coolant return pipe on back of heads - will drip fluid just behind drive axles either side.
4. Turbo lines - will drip fluid just behind drive axles either side.
6. Temperature sensor - will drip fluid just behind drivers side axle. Easy to see from above.
7. Recir pump located on u/x of drivers side frame rail.
8. Heater core - would smell coolant inside car
9. Overflow tank - will drip fluid in to firewall area
10 After run pump under intake manifold - coolant will be hard to see coming here and make it's way either towards the front of the engine or rear and not produce consistent puddles (and possible two at the same time).

Hoses should all be pretty obvious to tell if leaking. Some items are moderately straight forward to repair, while others are extremely difficult to near impossible without significant mechanical undertaking. Post your findings.

What if there is no visible dripping? the rate of fluid loss is so slow.
I will look again, see if i can find anything. once i get home and its up to temp. ill leave it idling and watch below, and then shut down and continue to watch... Ill report back with findings.

on a sad note... my wife discovered my car has cruise control and hers doesnt. so until i locate her a car that has... she is driving the RS6...

[lswing]

What if there is no visible dripping? the rate of fluid loss is so slow.
I will look again, see if i can find anything. once i get home and its up to temp. ill leave it idling and watch below, and then shut down and continue to watch... Ill report back with findings.

on a sad note... my wife discovered my car has cruise control and hers doesnt. so until i locate her a car that has... she is driving the RS6...

The ONLY time I've had a major issue driving was with cruise. I know this has happened to a few others also. While accelerating using the cruise, not gas pedal, the car shut down violently, shaking with all lights flashing, no gas control. Drifted over to the side luckily, restarted and fine. It's some issue with the ABS module or Cruise stalk...forget exactly, I just don't accelerate with cruise:)

[ben916]

Hi All,

I really hope this isnt going to be a big issue. But I have been noticing that the coolant has started to drop in my RS6, but very slowly... it is roughly a Liter for every 1000 miles driven.

Looking for the leak is proving really difficult. has anyone had this before?

Assuming you have a garage to park in each night, place a large piece of cardboard under the car but make sure you remove the engine tray as it can block the location of your leak.

EDIT: or have your dealership/tech run a check to pressurize the system, the leak will come spraying out (for me it was the radiator AND the oil cooler plastic pipe)

[bmlee007]

Need confirmation of exact location below your car on where puddle of coolant forms. Aside from a catostrophic head gasket failure, there are only so many locations coolant will leak.

1. Aux rads located in front of each wheel
2. Radiator - front clip
3. Coolant return pipe on back of heads - will drip fluid just behind drive axles either side.
4. Turbo lines - will drip fluid just behind drive axles either side.
6. Temperature sensor - will drip fluid just behind drivers side axle. Easy to see from above.
7. Recir pump located on u/x of drivers side frame rail.
8. Heater core - would smell coolant inside car
9. Overflow tank - will drip fluid in to firewall area
10 After run pump under intake manifold - coolant will be hard to see coming here and make it's way either towards the front of the engine or rear and not produce consistent puddles (and possible two at the same time).

Hoses should all be pretty obvious to tell if leaking. Some items are moderately straight forward to repair, while others are extremely difficult to near impossible without significant mechanical undertaking. Post your findings.

Number 3 was the cause of mine. I would come to a stop after spirited driving and get the burnt coolant smell and smoke from under the hood. As ben said, pressure check will show the culprit. It's a difficult one to find on your own.

[Knowa]

The ONLY time I've had a major issue driving was with cruise. I know this has happened to a few others also. While accelerating using the cruise, not gas pedal, the car shut down violently, shaking with all lights flashing, no gas control. Drifted over to the side luckily, restarted and fine. It's some issue with the ABS module or Cruise stalk...forget exactly, I just don't accelerate with cruise:)

This is a real thing? Audi, the king of quality give you a self destruct button in the car that also doubles as a regularly used function...

[Knowa]

Pressure test might be a good idea, thanks man! I think I even have the stuff to do it myself. what kind of pressure does the system operate at under normal driving conditions?

[G2]

Might want to also remove the spark plugs. See if anything is looking a bit too clean.

Otherwise, don't pressure test over 15psi (18-20 is the highest I've seen on newer cars). Operating pressure seems to be in the 12-13 PSI range based on the last RS6 while running the engine for some time. Sometimes leaks are noticed at lower pressures, in the 5PSI range, not at higher pressures.

Water pumps are prone to leak. Especially if the paper gasket was used. See it on every V8 so far.

[SteveKen]

Need confirmation of exact location below your car on where puddle of coolant forms. Aside from a catostrophic head gasket failure, there are only so many locations coolant will leak.

1. Aux rads located in front of each wheel
2. Radiator - front clip
3. Coolant return pipe on back of heads - will drip fluid just behind drive axles either side.
4. Turbo lines - will drip fluid just behind drive axles either side.
6. Temperature sensor - will drip fluid just behind drivers side axle. Easy to see from above.
7. Recir pump located on u/x of drivers side frame rail.
8. Heater core - would smell coolant inside car
9. Overflow tank - will drip fluid in to firewall area
10 After run pump under intake manifold - coolant will be hard to see coming here and make it's way either towards the front of the engine or rear and not produce consistent puddles (and possible two at the same time).

Hoses should all be pretty obvious to tell if leaking. Some items are moderately straight forward to repair, while others are extremely difficult to near impossible without significant mechanical undertaking. Post your findings.

11. Plastic coolant pipe bridging the block and the primary oil cooler assembly.

How on earth did you forget that one.....

[ben916]

11. Plastic coolant pipe bridging the block and the primary oil cooler assembly.

How on earth did you forget that one.....

This is what happened to me except it wasn't a graceful leak, it was where my coolant level was UNDER the minimum level and there was a rather large puddle of pink under the passenger front... It was an "oh $hit! hope my warranty covers this!" $5200 later and a engine drop and new radiator

[Knowa]

Reading this site is making me feel as if I have a ticking time bomb, might just be better off buying an R32... LOL

[Bigglezworth]

Pressure test might be a good idea, thanks man! I think I even have the stuff to do it myself. what kind of pressure does the system operate at under normal driving conditions?Most coolant systems are 13-15psi.


Reading this site is making me feel as if I have a ticking time bomb, might just be better off buying an R32... LOLDon't be misled. Same can be said with ANY car....the piddly R32 included.

[Bigglezworth]

11. Plastic coolant pipe bridging the block and the primary oil cooler assembly.

How on earth did you forget that one.....Ha! Right. How was that one missed. lol

[Knowa]

Does it matter where I put the pressure in?
My thought is to take that small hose that comes from the plastic bottle in fire wall, and seal the part on bottle, then connect that hose to a compressor with a gauge... and pressure to 15 PSI

Fair play on the R32 comment. all cars have issues.

[Knowa]

Hi guys,

I found the water leak, it is coming from the front right corner of the car. I would like to do this properly, has anyone done a guide on removing the front bumper?

Thanks for the help this far.

[lswing]

Hi guys,

I found the water leak, it is coming from the front right corner of the car. I would like to do this properly, has anyone done a guide on removing the front bumper?

Thanks for the help this far.

Either coolant/oil cooler pipe or aux radiator. Radiators are bolted right behind ICs, not the worst to inspect. Use "site:rs6.com bumper removal" in Google. Also Bufkin Pipe if that's what's needed, although I think it usually leaks oil.

[MaxRS6]

Most coolant systems are 13-15psi.

Don't be misled. Same can be said with ANY car....the piddly R32 included.

Our R32 has been much much much much much much much much much mo mo mo mo mo mo mo mo mo mo mo mo mo mo reliable than Crazy...

Well- The R32 did require new brake pads recently after 70K miles. It has not dropped any oil or coolant to date. Other than the scheduled maintenance, the R32 has not been in the shop. It is a ton of fun to drive.

http://i827.photobucket.com/albums/zz195/MaxRS6/Tiger%20Car/PIC_0905.jpg


However; I can't argue with the fact every car has issues...;0

[lswing]

^^^Nice ride for your teenager:)

[RSoverAll]

^^^ too funny

[MaxRS6]

LOL- It has been a great reliable car for her. 45 mile round trip to high school (and many other travels) during those years. Easy to maneuver, safe, did I mention reliable, a bit of power for the highway mergers, and the brakes nicely stop the thing. It ruled out her trying the old "I couldn't get the car started" late curfew excuse. :)

It is now tooling her around for her first college year.

edit: Funny story. One of her male passengers at college was arguing with her about the stopping power. Something about his big truck could stop just as fast. Well...she decided to pull into one of the large college parking lots, sent it up to about 50 and stomped on the brakes bringing it to a nice stop. She told me that stopped the argument.

[RSoverAll]

Hi guys,

I found the water leak, it is coming from the front right corner of the car. I would like to do this properly, has anyone done a guide on removing the front bumper?

Thanks for the help this far.

I see you found the leak already but figured I would share this anyways. This has helped me many times before. You can rent a similar tool at most auto parts stores.16088 16089

Oh and you would need the green threaded adapter for most VAG cars.

[Bigglezworth]

Hi guys,

I found the water leak, it is coming from the front right corner of the car. I would like to do this properly, has anyone done a guide on removing the front bumper?

Thanks for the help this far.Here's hoping it's a passenger aux radiator, one of the hoses feeding the aux radiator, or a lower rad hose. You do not want it to be the oil cooler pipe.

[G2]

Normally when I see that on the V8's it's the water pump leaking.

[Knowa]

Water Pump will be replaced as soon as those parts arrive... I'm hoping its not the issue or the car is grounded until that time.

@ Iswing - Thanks for the link, will check it out and get to it.