Heat dissipator exchange cayenne diesel

[mrpseudonym]

Hi, was after opinions of any diesel experts out there. My MY11 diesel cayenne recently went into the dealer to have the heat dissipator exchange replaced. A day later the coolant light came on, so vehicle was returned. Coolant was topped up and I was on my way again. Two days later while on an extended drive the coolant light came on again, I was in the middle of nowhere so rang the dealer, and was told to top up the coolant tank with water and bring car back when I could. I kept driving and 10km later the oil over temperature warning came on. I immediately stopped the car. Car was towed to dealer.
Throughout all of this the coolant temp remained rock solid at normal level, and another clue was that when I put the heater on to try and take heat away from the engine no hot air came through.
Clearly the job was done incorrectly in the first place by the dealer, but when I get the car back I want understand why and whether there is any lasting damage. Is it possible for water to get into the crankcase if the heat exchange is fitted incorrectly (like head gasket problems)? I looked into the oil filler cap and saw no sign, but that doesn’t mean it wasn’t there.
Any opinions welcome.

[mollytherocker]

There are a lot of assumptions there.

If the car is under warranty, let them deal with it.

[mrpseudonym]

mollytherocker said:

There are a lot of assumptions there.

If the car is under warranty, let them deal with it.

I tried to keep it simple. Among other things I left out all the swear words and anger that accompanied the fact that a reputable dealer had screwed up a job (that should not have needed to be done on a 5 year old car in the first place!) so badly, and left me, my family and a weeks worth of luggage stranded by the side of the road in the middle of nowhere waiting for a tow truck.

Car is not under warranty. I am trying to get an understanding of what might have gone wrong and what potential exists for long term damage so I know what to believe when the dealer tries to tell me "the problem is all sorted now sir".