I recently bought a 2001 allroad with 2.7T motor and 6-speed dual-range gearbox. It has done just 80,000km or 50,000 miles.

I had the ecu flashed with a GIAC St I tune last week.

I noticed a slight smell of coolant after a trip a couple of days ago. Today the weather was much warmer (almost 30C or 85F) and after a short run I parked the car. I returned to find a fair-sized pool (perhaps a pint or two) of liquid seeping out under the RH front door. I drove to a mechanic (maybe 5 miles), and just before I got there the low coolant light came on.

As soon as I parked and switched off fluid could be seen running under the car. The engine was bubbling and steaming a little. The collant reservoir was empty and we added liquid (water only at this stage) which came straight out the bottom of the car. When we got the undertray off, most of the fluid seemed to be falling roughly under the LH headlamp - ie at the front LH of the engine. The mechanic couldn't see much (it IS an Audi...) and couldn't locate the main leak at all but he thought he saw some fluid leaking at the back of the engine near the heater hoses. There was a relatively small amount coming falling below the RH rear of the engine.

From the location of the fluid leakage described above, does this sound consistent with auxiliary/secondary water pump failure? Is it possible there could be a simultaneous failure of the plastic heater hose T-piece?

I know this has been regularly written up, but wanted to narrow down the possibilities before planning my response.

Thanks all

 

Because anti-freeze can run down/around and drop from anywhere, it's hard to say where your original leak is. Your mechanic should really perform a pressure test of the system. There IS a coolant pipe which runs across the back of the engine and it has two temperature sensors in it. (one on each side) Could be leaking from one of those, could be your after run pump, could also be one of the feed/return lines to one of your turbos. (turbo's are cooled by anti-freeze) Pressure test takes all the guess work out of it.

 

Thanks swamper. I don't know how successful a pressure test is going to be when there's a massive breach in the system!! I think the best method might be just to take the covers off the top of the engine and fill the reservoir, using a torch to try and spot wher it's flowing from.

My guess is it will be from the secondary pump between the cylinders. I haven't had time to do this because I had to abandon the car at the mechanic's workshop and accept a lift home with him as he happens to live in the same village. The allroad wasn't going to be motoring anywhere that evening...

 

I just realised I didn't follow through with the results of my breakdown.

Turns out the coolant system was full of rusty water and this was eating away at various metal parts of the motor. It finally ate right through the pipe that runs across the top of the motor at the back, between the cylinders. Doesn't seem to have a name apart from Water Pipe and a cost of $600.

While the car is in showroom condition and has been dealer-serviced its entire life (serviced at 12 month intervals as the 2 POs put on such a low mileage), it seems the dealer had not been as attentive as he should have been. The invoice for the last service (less than 3 months before I bought the car) listed "checked coolant" along with the other service items, but it appears the coolant was not checked. They could not have done a visual check as the expansion tank was so discoloured with rust you couldn't see through it, and if they had lifted off the cap they would have seen the liquid was dark brown, the inside of the cap was covered in scum and there was no O-ring.

Unfortunately, I did not discover this until I had had the car repaired by an indy and paid him the money. The dealer doesn't seem to think I have a claim, although he has offered to sell me parts in the future at a discount. As this is unlikely to be anywhere near the price I pay when I import parts from the US, this is not going to be of much use to me.

Of course I should have checked the car more thoroughly before buying - but when the service manual is full of dealer stamps and you have a pile of dealer invoices, you sort of think it's a pretty safe bet.

The worry for the future is what else is corroding away in there? Radiator? Turbos? Water pump?

We live, we learn

 

HEY MAC,

how many miles on the engine?

 

Sounds like typical mixing of audi and "green" cheap auto store coolant which is a big no-no. When they are mixed, they gel up and start eating coolant.

I would strongly advise you to replace the coolant again and put in audi stuff. While doing so, ensure your indy runs two loads of coolant system cleaner so that as much as possible it dissolved and removed from the system.

The only known part being very sensitive to gelling up is heating matrix. If that clogs, the replacement is extremely expensive due to labor cost.

 

The PO never did a thing to the engine - never even raised the bonnet. He never did as much as 5,000 miles per year, so he left everything to the annual dealer service.

This wasn't a mix of anti-freeze - this was the original stuff being left in there for ten years, possibly topped up occasionally with tap water.

It was so brown and rusty there was rust scum around the bottom of the expansion tank cap and the tank itself is completely discoloured.

My indy is very particular - I have absolute faith he flushed out the system properly and eventually replaced it with the right stuff.

I've given the dealer notice that I'll be chasing him all the way to court if anything happens in the next couple of years which I can trace to his failure to service the car in the way he claimed.

 

Less than 50,000 miles when I bought it. Now about 65,000

 

How's the heater core? Getting any heat? With all this junk in the cooling system, I bet your core is plugged, if not fully, at least partially.

 

No problems with the heater at all. I believe the motor has been very thoroughly flushed and the coolant is retaining its clear pink colour.

As I said, the real worry is what components may have already been corroded and are just waiting for a dark, cold, rainy night when I'm 400 km from home....