Greg5OH

Well, it seems the loss of coolant has been speeding up i think. Reservoir is dry this morning.

I dont see any leaks, nor do i smell hot coolant anywhere.
I suppose next step is to put some dye in it, pressurize the system and see if i can spot anything around the engine or reservoir itself, or underneath the car.
no oil in coolant, or coolant in oil, doesnt hear or smell boiling coolant in reservoir when ran hard.

Anyone have this happen? Car was not overheated in our ownership, has just over 80k miles now.
Dont think its headgasket (i hope i should say)
Any other specific parts to go over?

3RDGENFRANK

My 2007 S8 just started doing this as well. There is an elbow just to the rear of the passenger side valve cover. The elbow has a bleeder screw on the top and directs coolant through the firewall to the heater control valve under the PCM. Mine actually broke completely yesterday.

If this is your problem, you have to buy the entire hose with the fitting. The part number is 4E0819371R and is just under $100.

Good luck.

MP4.2+6.0

You really don't need any dye in my experience. The antifreeze itself turns out to be helpful in leak finding.

You are looking for any of:

• 1. Pink cotton candy like wispy stuff if it kind of sprays out and dries
• 2. A pinkish tan kind of crusty stuff for other leaks that also dry or get baked on a hard part.
• 3. Whitish pink stains running along or off hot metal or similar surfaces.

I have found the majority of my leaks over the years only by getting underneath w/ belly pan off. On D3 W12 over the 10 years, under warranty I found a very slightly fractured radiator they replaced under warranty. That hardly showed any pink color, and was mostly just damp in a lower corner. Had a leak at either upper hose o ring or water pump (both replaced) that showed version #3 of above on bottom of oil pan when I first saw it. Had version ##1 and 2 when the coolant overflow tubing got heat soaked, brittle and started splitting. Early on, also had a slightly loose clamp at the heater valve that dealer tightened under warranty; exhibited version #1 signs. When you pull pan itself, sometimes it either shows wetness or some flavor of #3 that can help you triangulate where to look above the belly pan spot in motor area for a corresponding issue.

Greg5OH

unfortunately my belly pan is trashed with oil from PO not repalcing the crush washer.
I now also use the vacuum extractors (best tool i have purchased for this car!)

with the v10 it is super hard to see anything around the engine, but definitely warrants a look under with belly pan off.
My cummins engine leaves a slight pink/white trace when it was leaking coolant but hard to see sometimes when it dries. I put dye in and wow can instantly see the wet spots without even looking hard for them.

Good to know about those problem areas though, will go over them with a fine tooth comb.
With so many external cooling lines on these engines, i surely would hope/expect it is just one of them vs a head gasket.
plus no white smoke when accelerating or idling.

2004A8L

Relax head gasket isn't one of the common failures on these cars. As suggested look 👀 for the leak get a blanket and take a nap under the car you'll find it lol

volvopentaman

And a good tip to find coolant leaks.

Just start the engine and let it idle for like an half hour to an hour to get it warm. And i mean idle, DON'T drive around with it, it will just vaporize the leak making it harder to find.

Leaks are usually found around coolant hose couplings, connectors or clamps. Check every hose, there are a lot of them.

ScottCNelson

On a spirited drive with the AUDI Club Carolinas because the plastic bib broke in two, leaving me on the side of the road. Fortunately, we had the owner of a Porsche/AUDI/VW shop in the group who McGivered the hose together using zip ties and super glue. Got me back to the base hotel and hopefully I can limp home tomorrow. Typical AUDI "known infamous part" crap.

BASARAB

How did you replace it? Did you have to get the intake manifold out?

BASARAB

Took a look today and yes, it is indeed the same part what broke off on my S8 with 140k miles. The intake manifold does not have to come out. Even though its a tight fit, it is possible to replace with just moving couple fuel lines out of the way.
You will need need hose pliers to make things easier https://www.harborfreight.com/3-piec...ers-37909.html.
I thought about replacing the broken part with a generic 3/4 connector from O'Reily auto parts, but figured I might need a bleed screw later on



now gotta order the correct part and wait for it to arrive