Renault Koleos long-term cooling-coil leak causing oil loss and compressor seizure

Sifu White explains what happened

Prices, repair times and warranty terms mentioned in the video applied at the time. Ask the workshop about current arrangements.

What can we see? The compressor is badly seized. This is a Renault Koleos. The car came to Sifu White last year because the compressor had started making noise. We provided a quotation and advice, but the owner did not repair it then. After a year, the compressor finally seized severely.

The original cause is confirmed as a leaking cooling coil. Continued leakage reduced both refrigerant and compressor oil until the compressor failed and seized. Repair requires the compressor, condenser and cooling coil to be inspected and replaced according to condition. Undamaged piping can still be flushed and reused. Some parts for this model share specifications with certain Nissan models.

The earlier quotation was higher because original Nissan parts were difficult to find and we had to use a more expensive supplier option. We can now obtain an original Nissan part at a lower price, giving the customer better value than the previous quotation.

At least this option offers better value.

Why cooling after a regas does not prove a repair

Refrigerant circulates through a closed circuit; it is not fuel that the engine consumes. If cooling returns after charging and then deteriorates, the investigation should establish whether there is a leak, whether the previous charge matched the specification, and whether another control or heat-rejection problem is present. The initial return of cold air describes performance at that moment. It does not show that a leaking component has been repaired.

A model’s familiar failure pattern is a starting point, not proof. The condenser, connections, hoses, compressor seals and evaporator inside the cabin are different possible inspection locations. An oil stain can guide a leak test, but it is not a substitute for confirmation. Finding one leak also does not clear every other part of the circuit. After repair, the sealing and cooling performance need to be checked again under conditions relevant to the original complaint.

How contamination changes the repair scope

Refrigerant and lubricant travel through several components. Debris from internal compressor wear can therefore create a problem beyond the compressor itself. Installing a replacement while contamination remains in circulation can expose the replacement to the same problem. The investigation should distinguish the source of damage, the spread of contamination and the condition of components that might still be serviceable. Neither “compressor only” nor “replace everything” is a complete diagnosis on its own.

Whether flushing is appropriate depends on component construction, contamination and the manufacturer’s procedure. Fine passages and trapped debris can be difficult to clean reliably. Compressors, driers and metering devices cannot simply be treated as open lengths of pipe during flushing. Oil colour is one observation, but colour alone does not measure moisture content or establish that every component has failed. An itemised explanation should identify what needs replacement, what can be cleaned, and the evidence behind each decision.

What to tell the workshop about your own car

You do not need to guess a part name first. A clear description of what actually happens is often more useful for reproducing the complaint than requesting a particular replacement.

• Record the last regas date and how long cooling lasted.
• Ask for an itemised scope separating contamination work from leak repair.
• Include the model, year, recent repairs and what changed before or after the symptom began.