Symptoms
Coolant pushed out of the expansion tank, rising temperature after recent leaks or top-ups.
The fix, step by step
- LandyZone members advise ruling out an airlock (a thermostat sitting in air won't open) and a weak pressure cap, which lowers the boiling point, before pulling the head.
- Bleed the system properly, fit a new cap, and only then do a combustion-gas test if the symptoms continue.
Tools & part numbers
- Coolant, bleed procedure from the workshop manual, block tester
- expansion tank cap
Where to buy the parts
NTC7161 expansion tank cap 15 psi, 200Tdi/300TdiLR Direct ↗Amazon ↗
Coolant & antifreeze, 5 LLR Direct ↗Amazon ↗
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Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.