Radiator replacement

A6 All/ S6 All
#1

When it rains, it pours… coolant out of the front end. As I was pulling into my driveway today, my coolant light came on (JHM just flushed and refilled it like 1000 miles ago) and when I got out, water was spewing out the front end. Literally a jet of coolant coming out the front grill. When the coolant finally drained completely it spewed steam for the next 20 minutes. From what I can tell, it appears to be one of the vertical runners on the passenger side of the radiator.

So my question is simply: What do I do? Is this a difficult part to replace? Should I just have my local shop order a new radiator and put it in, or is that going to cost a FORTUNE in labor? I have absolutely no idea where to begin.

Gah, it seems like this damn car can never go more than a couple thousand miles without forming some new coolant leak!!!

Also, what kind of coolant should I be putting in? JHM put in some red colored stuff. Obviously I’ll be needing to buy some tomorrow.

#2

I just shot JHM an email asking for the advice as well but I’m hoping someone can provide some insight here as well, the sooner the better, I kinda need my car :-\

#3

I believe g13 is the newest stuff. Saying that it all came out or almost all you should be on using it not knowing what jhm used. Also you’ll want to mix it 50/50 with distilled water. 2 gallons of coolants should get you full but if it is leaking topping off won’t get you very far.

#4

I would use only genuine coolant from audi.

#5

Thanks for that info, hopefully I can talk someone into driving me around town to pick this stuff up. And hopefully someone has an S6 radiator somewhat locally.

Anyone know if the process the same as a C6 A6? Obviously, DIY guides for S6’s are few and far between, but I can probably dig up a how-to on replacing an A6 radiator

#6

I’d be curious to know where it is coming from. Buy 6 gallons of distilled water and try and narrow down where it is coming from. Distilled water is $1a gallon at target fyi.
Also did jhm just use the little screw under the car on the driver side to empty it or did they remove hoses? Could it just be a house?

#7

I have no idea how JHM drained the coolant. This isn’t the result of the JHM work, this is just another problem that popped up that wasn’t a problem 2 weeks ago. I snapped this photo through my grill, obviously I couldn’t put my camera there while it was spewing hot coolant out the grill, but the red arrow show where the jet was coming from:

http://i.imgur.com/L1xWuZo.jpg

You can see how there’s like a folded piece of metal around the edge of the radiator, it seems the leak is inside that folded metal piece somewhere. Unfortunately I don’t think it’s a spot I can really do a temp fix on with some epoxy.

For reference, this is the spot where I took the photo:

http://i.imgur.com/1ZMbOyI.jpg

#8

Id say its the same process as on the a6, remove front bumper to access and away you go, filling/bleeding the system is something i wouldnt be confident doing on these cars myself though. I would just order replacement radiator and drop into your local shop asking for them to install and add new coolant

#9

JHM already got back to me (at 5:30am, wow!) and pretty much said the same thing - that with proper tools and parts anyone should be able to do it in a day. I’m going to call around this morning and see if any local shops are competent enough to handle this - I kind of doubt it considering my past experiences with those shops, but it’s worth a try before I tow my car a 3-hour round trip away.

#10

Update: My local shop says they can get any radiator parts I need today and install them by the end of the day, with 3.5 hours of labor. The guy I was talking to has never worked on a 5.2 V10 but he actually knew quite a lot about it surprisingly, and has worked on a C7 S6, so hopefully he is up to the job. We’re looking at probably $700-$800 all in. He’s also going to take a look at my exhaust rattle I was talking about before at 3k-4k RPM and see if he can pinpoint the source. If all goes as planned I should be back on the road by tonight.

After thinking about it, this really isn’t surprising that my radiator broke shortly after the overhaul. My coolant system has had pressure leaks for a long time, and when those finally got repaired by JHM it’s not surprising that when the system returned to normal pressure that it didn’t take long for the next aging part to break. There are at least 3 radiator parts (it’s a split radiator right?) and I’m only having them replace the broken one for now, hopefully that is enough for now. It was tempting to replace everything at once to save labor but I just can’t afford that right now, they’re just finding the leaking part and replacing only that.

#11

Another update: The leak is coming from the main radiator. The radiator is $500-something from Audi, plus obviously needs coolant flush and refill again, plus 3.5 hours labor comes out to $1277 total. Ouch. JHM would’ve for sure been cheaper but it’s kind of a rush. Won’t be done til tomorrow night and even that is really too long to wait.

#12

I just had the same thing happen about 4 months ago. Almost all the coolant came pouring out from the main radiator. Upon pulling the front end off, my shop diagnosed the exact same area had broken. Funny enough, I had just diagnosed that the coolant reservoir cap seal had gone bad (was looking small amount of coolant while system under pressure). A day after installing a new cap, the radiator blew. I came to the same conclusions as you that the system had not been under full pressure for a little while, and the radiator was the next weak link after system pressure was restored. I think I paid roughly the same, maybe $1100.00, or so, to get the radiator replaced. I also had the serpentine belt, idler pulley and tensioner replaced while they had the radiator out. Something to think about if you haven’t replaced yet.

#13

Thanks Frogger, that makes me feel a lot better that my diagnosis and solution is correct and that I’m not overpaying by a ton. That other stuff you mentioned was all replaced by JHM already a few weeks ago so I should be good to go with the new radiator!

#14

Its hard to tell from the pictures but it looks like lots of oxidation on the one side you showed. The rad units get weak in the corners and the side caps just weep coolant bad.

The good news is the rad was probably not working as efficently as it could have so a new one will be just what the dr ordered. Just make sure to look over the car really well when you pick it up. Lots of local shops tend to not know there way around the cars really well and a few doubble and tripple checks will be a good idea just to make sure they didnt miss something

#15

Ya it’s probably the original radiator, and considering that Frogger had exactly the same experience as me, it sounds like it was pretty much at the end of its life. I may add something about this to the Infodump thread, since it’s already happened at least twice now under nearly identical circumstances. At ~$350 for a new radiator (mine was over $500 because I’m being impatient and wanted one today), this is probably an item worth addressing, for any S6 owner, at around 100k miles when the front needs to come off for other servicing. Coolant issues are NOT fun to discover while you’re driving around, so I think a comprehensive list of coolant system failure points would be hugely helpful to the community. So far, in my experience and from reading what others have said about coolant leaks, they nearly all seem to occur somewhere around 100k miles, +/- 25k or so. Expansion tanks, hoses, that stupid Y connector, coolant cap, water pump… all those thing failed on my car between 100k and 120k.

#16

Ouch. I just ordered a new coolant reservoir cap because the seal is bad. Is there a way to “gently” test the rest of the coolant system for weaknesses before I install a new cap? My engine temp seems to be rock steady, so it might be cheaper to regularly top off the coolant tank when I top off the engine oil rather than to replace the radiator…

#17

Coolant pressure test? Mine was replaced last summer, too. Though it was caught while it was just starting to weep before a complete failure. Was in for the thermostat & waterpump at the time.

#18

C. Scott, your list covered what I’ve needed to replace on mine, except mine happened at an earlier interval. Expansion tank had hairline fractures at about 65k. Replaced expansion tank and the spider hose with the ridiculous plastic Y connector when I sheared the thing in half trying to remove one of the hoses. Expansion tank cap was replaced at 80k, along with the main radiator at 80k.
Anybody want to start talking oil leaks too. I’ve been going through those for the last 6 months now. Valve cover gaskets replaced at 75k. Lower oil pan gasket replaced at 80k (did it with the radiator). At 85k now and I’m hunting down another oil leak on the front. Fun stuff!

#19

I’ll put together a “coolant leak” page soon, something that can be a catch-all for coolant issues. Sounds like 80k-100k is about the timeframe then for addressing these items preventatively if you don’t want any surprises on the road and for the sake of saving money on labor by doing them all at once.

#20

Frogger
Not to thread jack, but where are you finding oil on the ground? The oil filter housing is a very common leak in these cars. I’M needs to come off so if you need a cleaning now would be the time to do that as well