A whiff of coolant!

[PD_GT3]

So my 94k mile Diesel S was using coolant, after a pressure test it was found that the rad had a tiny leak, new rad in & all was well....

Since replacing the rad, I've had to top the coolant up a few times, normal I thought after replacing the rad to allow for air burps etc but it just keeps going down at a rate of around 100ml per week along with a very faint smell of coolant when you park the car up.

I'm going to look into this further & if anyone has any pointers I would be most greatful.

[Guy]

Perhaps the new radiator is faulty too? Not unusual, I just had a new radiator in a VW Golf and the garage noticed that the new one also had a leak! Either that or something as simple as a coolant hose not being tightened during replacement.

The original leak in my Golf was very slow. I only noticed it after leaving the car parked with the engine running, leaving a pool on coolant on the drive. If the engine wasn't running then it didn't leak - lower pressure obviously. You could try this to see if you can identify the leak.

Was it replaced under warranty?

(PS: Impressed with your high mileage! Any other problems? DPF? Transfer box?) EDIT: Just seen your other post in the mileage thread!

[PD_GT3]

Thanks Guy, I'll look into that.

No DPF issues either, this has surprised me actually!

[Nuclear Nick]

Try running the engine a short while from cold, stop it, then release the coolant reservoir cap. Don't do this when it's hot! If there's no pressure build up when cold it could rule out a failed head gasket which would pressurise the system as soon as the engine is running.

If there's a smell of coolant then there's likely a leak somewhere. Presume you've checked the vent pipe from the coolant header tank? Otherwise it's careful checking of the system until you find the leak.

In the old days I've used Bars Leaks, and that was very effective, particularly on small leaks. But in the first instance see if you can spot a leak.

[TheTraveller]

I think if you can smell it somewhere, then it should be evident to see also. Is there any trace on the floor, underneath simultaneously. Another pressure test should expose it. Usually head gasket water leeks are burnt and blown out through exhaust, and are difficult to smell.

[ScotMac]

Impressed with 94k miles.

Presume there is no obvious signs of coolant around engine bay.

[Tech2019]

Not come across with coolant leaks from the diesel engines on Macan, but with that mileage possible EGR coolant lines.
Quiet common with the TDI V6 engines

[PD_GT3]

An update to this, I had a garage check for any signs of a leak & nothing, they too could smell the coolant though.

They looked deeper & searched for this issue under Audi Q5 & some results popped up, turns out my issues was the same, some seals on components on the engine valley had failed & actually filled the valley with coolant!

Pic below with it all removed.

This issue was impossible to see without removing the top end of the engine (intake manifold etc)