VW Transporter coolant leaks & pipes
The metal coolant pipes that run underneath a T5 are a known weak point. They rot from the inside out, and they tend to let go without much warning. Catching it early is the difference between a pipe and an engine.
- Family-run since 2020
- T5, T5.1 and T6
- Used parts on the shelf
What it usually looks like
Cooling faults give you warning signs. They are worth taking seriously.
Topping up the coolant
If you are adding coolant and cannot see an obvious puddle, it is often the underslung pipes weeping where you cannot see them.
Puddle under the middle of the van
Not the front. A leak from under the middle usually means the metal pipes rather than the radiator or hoses.
Temperature gauge climbing
Especially in traffic or on a climb. Stop. An overheated engine is a far bigger bill than a cooling repair.
Sweet smell after a run
Coolant burning off somewhere hot. Something is leaking even if you have not spotted it yet.
Heater blowing cold
Low coolant or air in the system will kill your heat long before the gauge moves.
Mayonnaise under the oil cap
Get it in quickly. That can point at a head gasket, and the sooner it is diagnosed the better.
How we sort it
Pressure test and find it properly
Coolant leaks hide. We pressure test the system rather than replacing parts one at a time and hoping the puddle stops.
Metal pipe replacement
The underslung T5 pipes are the usual culprit on an older van. We replace them, and while the van is up we check the rest of the system rather than leaving you to come back in a month.
Pumps, thermostats and radiators
Water pumps, thermostat housings, hoses and radiators. If your cambelt is near due, doing the water pump at the same time saves paying twice for the same labour.
Coolant leaks, questions and answers
Why do the T5 coolant pipes fail?
They run underneath the van, exposed to road salt and water, and they corrode from the inside as well as the outside. It is age and mileage rather than anything you have done wrong.
Can I keep driving if it is only losing a little?
We would not. Coolant loss is unpredictable, and the failure mode is usually sudden. An overheat can cost you a head gasket or the engine. Get it looked at.
Do you replace the water pump with the cambelt?
We recommend it. The labour overlaps almost entirely, so doing both together is far cheaper than doing them separately a year apart.