"The RB20DET heats up the engine compartment more than the RB25DET — cooling is the first thing to address on any example."
RISKY
62/ 100
"Old turbo six needs serious pre-buy diligence"
276
Max HP
540
Torque Nm
5,000
Oil interval km
0
Recalls
7
Known issues
Known Issues
Chronic Overheating and Cooling System Degradation€400-1,800 · 80,000-160,000 kmCRITICAL
The RB20DET is well-documented in community forums for running hot, with reports of clogged radiators and insufficient cooling capacity even after fitting larger radiators and new water pumps. The engine generates significant heat in the engine bay compared to larger RB variants, making cooling system maintenance critical on any aged example.
Temperature gauge creeping into the upper zone under load
Coolant loss without visible external leaks
Persistent overheating despite new water pump installation
Forum evidence documents compression loss in individual cylinders on higher-mileage RB20DET engines, with at least one case citing cylinder 3 failure specifically. Given the engine age (30+ years), worn piston rings and valve seals are a realistic concern on unrestored examples.
Rough idle on a specific cylinder
Loss of power under boost
Increased oil consumption
Blue smoke from exhaust on startup
DIY: Moderate
EGR System Faults and Carbon Buildup€100-600 · 80,000-150,000 kmHIGH
EGR valve issues are documented in forum discussions, including seized EGR valves that will not budge. On a 30-year-old engine, carbon buildup in the EGR system and intake is expected. Many owners perform an EGR delete by plugging the vacuum hose to the actuator as a common fix.
Rough idle
Check engine light
Flat spot under light throttle
Poor fuel economy
DIY: Easy
ECU Wiring and Grounding Issues€150-800 · Any mileageHIGH
Multiple forum threads highlight ECU grounding problems and wiring faults specific to the RB20DET, including injector and ignition wiring issues. On cars of this age, degraded wiring looms, poor earths and aftermarket ECU modifications are common causes of intermittent faults.
Intermittent no-start
Check engine light with multiple fault codes
Misfires or injector drop-outs
ECU warning lights of varying colours
DIY: Hard
Turbocharger Wear and Oil Feed Issues€500-2,000 · 100,000-180,000 kmMODERATE
The single turbocharger on the RB20DET is aged on any surviving R32 example. Shaft play and oil seal degradation are age-related risks. Oil feed and return lines degrade over time and can cause oil starvation or leaks onto the turbo housing, accelerating wear.
Whining noise from turbocharger
Blue smoke under boost or deceleration
Oil leaks at turbo oil feed or return
Boost lag or reduced peak boost
DIY: Moderate
Aged Rubber and Seals Throughout Engine€200-900 · All mileages on 30+ year old carsMODERATE
Any R32 RB20DET is now over 30 years old. Valve cover gaskets, cam seals, crank seals, coolant hoses and intake boots will have deteriorated regardless of mileage. Oil and coolant weeping is expected if these have not been replaced.
Oil seeping from valve cover
Oil at front or rear crank seal
Cracked or swollen coolant hoses
Split turbo intake or boost hoses causing boost leaks
DIY: Easy to Moderate
Clogged or Restricted Radiator€150-600 · 80,000-150,000 kmMODERATE
Forum sources specifically advise flushing the radiator from the cold side to the hot side using pressurised water, indicating internal silting and clogging is a known and common issue. Mixed coolants over decades accelerate scaling.
Slow warm-up followed by rapid overheating
Poor heater output
Coolant that is discoloured brown or rusty
DIY: Easy
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Buying Checklist
Perform a full cold-start compression test on all six cylinders — reject any cylinder reading more than 10% below others
Pressure-test the entire cooling system and inspect coolant colour — brown or rusty coolant indicates decades of neglect
Check turbocharger shaft play by hand and look for blue smoke on start-up and hard deceleration
Scan the ECU for fault codes and inspect the wiring loom for brittle insulation, poor repairs or non-standard modifications
Inspect all rubber boost hoses, intake couplings and coolant hoses for cracking — replace the full set if in doubt
Verify full service history or at minimum confirm recent oil changes with receipts — oil starvation destroys these turbocharged engines quickly
Service Reality
Community oil interval5,000 km
Oil specification10W-40 or 15W-50 semi/full synthetic meeting API SN or higher; community strongly recommends 5,000 km intervals given turbocharger heat soak on a 30+ year old engine
Est. ownership cost (2yr)€1,500-4,000 per year depending on condition at purchase and extent of deferred maintenance; higher if turbo or engine work is required
The RB20DET in an R32 GTS-T is a rewarding engine for an enthusiast willing to invest time and money upfront, but it is emphatically not a buy-and-drive proposition. Every surviving example is now over 30 years old and will have cooling, sealing and wiring issues that must be addressed immediately after purchase. Budget at least €1,000-2,000 for immediate recommissioning work regardless of how good the car looks. Only buy from a seller who can demonstrate recent cooling system work, an oil change history and a clean compression test — walk away from anything that does not check those boxes.
Parts People Buy
RB20DET Valve Cover Gasket SetLink unavailable
RB20DET Silicone Coolant Hose KitLink unavailable
RB20DET Turbocharger Oil Feed Line KitLink unavailable
RB20DET Silicone Boost Hose KitLink unavailable
Nissan R32 Thermostat and Housing KitLink unavailable
RB20DET High-Flow RadiatorLink unavailable
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