MajorCommonFluid Leaks

Renault Megane: K9K 1.5 dCi Injector Return Rail Banjo Bolt Washer Leak

K9K 1.5 dCi Injector Return Rail Banjo Bolt Washer Leak is a common fluid leaks fault on the Renault Megane on the 2002–2016 cars, and we rate it major. Putting it right costs $180 to $550 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 27 documented faults on the Renault Megane.

Vehicle: Renault Megane
Engine: 1.5L
Years: 2002–2016
Fuel: diesel
System: Fluid Leaks

This page covers the Renault Megane as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Renault Megane faults27 documented faults on this model

What you are looking at

What goes wrong

The K9K 1.5 dCi common-rail diesel engine uses banjo bolt fittings with copper or aluminium crush washers to seal the low-pressure injector fuel return rail to the cylinder head gallery. These washers harden and lose their sealing ability through repeated heat cycles generated by proximity to the diesel combustion environment and turbocharger. Once the washer fails to maintain a pressure seal, diesel fuel weeps or sprays from the banjo joint onto the hot exhaust manifold and turbocharger housing. The resulting fuel mist contacting hot exhaust surfaces creates a serious engine bay fire risk, particularly during motorway driving when sustained engine temperatures are highest.

What you would notice

Persistent diesel fuel odour from engine bay during and after driving
Visible wet fuel residue or oily staining around injector return rail banjo fittings
Slight smoke or vapour from engine bay after sustained high-speed driving
Higher than expected fuel consumption without change in driving style
Carbon-stained discolouration on exhaust manifold surface near injector area

How to check it

Where to look. Top of K9K cylinder head at injector return rail banjo bolt fittings, adjacent to the inlet manifold and turbocharger

With engine at operating temperature, inspect injector return rail banjo bolt fittings on top of the cylinder head for any wet diesel staining, fuel residue or discolouration around the bolt head and washer interface; examine exhaust manifold surface directly below the banjo joints for carbonised fuel traces from historical leakage; verify washers have been proactively renewed in service history.

Parts involved: Fuel injector.

What it costs to put right

$180 to $550 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has there ever been a diesel fuel smell from the engine bay?”
“Have the injector return rail banjo bolt crush washers been replaced?”
“Has any fuel leak been investigated or repaired?”
“Is there any smoke or smell from the engine bay after motorway driving?”

Now check the Renault Megane you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Renault Megane buyer questions

Is k9k 1.5 dci injector return rail banjo bolt washer leak serious on a Renault Megane?

We rate it major and common on the Renault Megane. The K9K 1.5 dCi common-rail diesel engine uses banjo bolt fittings with copper or aluminium crush washers to seal the low-pressure injector fuel return rail to the cylinder head gallery. These washers harden and lose their sealing ability through repeated heat cycles generated by proximity to the diesel combustion environment and turbocharger. Once the washer fails to maintain a pressure seal, diesel fuel weeps or sprays from the banjo joint onto the hot exhaust manifold and turbocharger housing. The resulting fuel mist contacting hot exhaust surfaces creates a serious engine bay fire risk, particularly during motorway driving when sustained engine temperatures are highest.

How much does it cost to fix on a Renault Megane?

$180 to $550 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Renault Megane years are affected?

Our research records this fault on the 2002–2016 Renault Megane. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.