MajorCommonFluid Leaks

Nissan Skyline: RB25DET Series 2 Fuel Injector O-Ring Leaks

RB25DET Series 2 Fuel Injector O-Ring Leaks is a common fluid leaks fault on the Nissan Skyline on the 1993–1998 cars, and we rate it major. Putting it right costs $350 to $750 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 41 documented faults on the Nissan Skyline.

Vehicle: Nissan Skyline
Engine: RB25-DET
Years: 1993–1998
Fuel: petrol
System: Fluid Leaks

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

All Nissan Skyline faults41 documented faults on this model

What you are looking at

What goes wrong

Series 2 R33 Skylines (post-1995 facelift) fitted with the updated RB25DET suffer from fuel injector o-ring deterioration. The o-rings harden and crack with age, allowing fuel to leak at the injector-to-rail and injector-to-intake-manifold sealing points. This creates a fuel smell in the engine bay, raw fuel contamination of the oil if fuel runs down the bore, and a significant fire risk if fuel contacts hot exhaust components. The fault is well-documented on Series 2 engines due to a specific o-ring compound used in the factory assembly.

What you would notice

Fuel smell in engine bay particularly after shutdown
Visible fuel staining or wetness around injector bodies
Rough idle or misfires from injector seal leakage affecting mixture
Oil that smells of fuel (dilution)
Hard starting when hot

How to check it

Where to look. Fuel injectors seated in the intake manifold runners, clamped by the fuel rail on top

With the engine at operating temperature, open the bonnet and smell around the inlet manifold area.
Inspect around each injector body and the fuel rail connections for fuel staining (shiny wet residue or dried varnish deposits).
Press a clean white cloth against each injector base — any fuel transfer confirms a leaking o-ring.

Parts involved: Fuel injector.

What it costs to put right

$350 to $750 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

“Have the fuel injector o-rings been replaced?”
“Is there any fuel smell in the engine bay or cabin?”
“When was the last fuel system service?”

Now check the Nissan Skyline 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.

Nissan Skyline buyer questions

Is rb25det series 2 fuel injector o-ring leaks serious on a Nissan Skyline?

We rate it major and common on the Nissan Skyline. Series 2 R33 Skylines (post-1995 facelift) fitted with the updated RB25DET suffer from fuel injector o-ring deterioration. The o-rings harden and crack with age, allowing fuel to leak at the injector-to-rail and injector-to-intake-manifold sealing points. This creates a fuel smell in the engine bay, raw fuel contamination of the oil if fuel runs down the bore, and a significant fire risk if fuel contacts hot exhaust components. The fault is well-documented on Series 2 engines due to a specific o-ring compound used in the factory assembly.

How much does it cost to fix on a Nissan Skyline?

$350 to $750 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 Nissan Skyline years are affected?

Our research records this fault on the 1993–1998 Nissan Skyline. 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.

How do I check for it before I buy?

With the engine at operating temperature, open the bonnet and smell around the inlet manifold area. Inspect around each injector body and the fuel rail connections for fuel staining (shiny wet residue or dried varnish deposits). Press a clean white cloth against each injector base — any fuel transfer confirms a leaking o-ring. Look here: Fuel injectors seated in the intake manifold runners, clamped by the fuel rail on top