1993 Nissan Sentra Problems: 6 Known Issues

On the 1991-1999 Nissan Sentra, the defining electrical failure of the 1990s Sentra. On both the GA16DE (1.6L) and SR20DE (2.0L), the crank angle and camshaft position signals are generated by an OPTICAL sensor (a slotted disc read by an LED/photo-diode) housed inside the distributor. Two age-related failure modes dominate: (1) the internal distributor shaft seal fails and engine oil weeps up into the distributor, coating the optical disc and electronics; and (2) the optical encoder/electronics degrade or the encoder wheel works loose. As the sensor warms with the engine it drops out intermittently, so the classic pattern is an engine that runs, then stalls once hot and refuses to restart until it cools. At high mileage it becomes a hard-crank or no-start. Because the sensor is integral to the distributor, Nissan supplies it only as a complete distributor assembly.

On the 1991-1999 Nissan Sentra GA16DE 1.6L I4, aging GA16DE engines commonly develop gradual oil consumption that owners don't notice as a puddle because it is being burned. Contributing factors are the small PCV baffle plate gasket in the valve cover failing, which lets the PCV system pull oil into the intake, a clogged PCV valve, and at very high mileage hardened valve stem seals and worn piston rings letting oil into the combustion chambers. Because the loss is combustion rather than a visible leak, neglected engines can run low on oil and suffer bearing wear.

On the 1991-1994, 1998-2001 Nissan Sentra SR20DE 2.0L I4, the SR20DE (Sentra SE-R and 200SX SE-R) uses a timing chain, and the original hydraulic tensioner leaks down oil overnight. On a cold start after sitting, or at low RPM when hot, the chain slaps the guides and produces a loud metallic rattle/clatter from the timing cover for a few seconds. Nissan acknowledged this in Technical Service Bulletin NTB92-056 for 1991-92 SR20DE engines, describing 'a rattle in the timing chain area for a short period when the engine is started after a one night soak or at low RPM caused by a leak-down of oil in the chain tensioner.' Left unaddressed, weak tensioners and brittle plastic guides can let the chain go slack, wear or shatter a guide, and in the worst case skip a tooth causing valve damage on this interference engine. Note: in the Sentra line the SR20DE was fitted to the B13 SE-R (1991-1994) and the 1998-2001 Sentra SE 2.0; the 1995-1998 SR20DE lived in the 200SX SE-R, but the failure mode is identical across the family.

On the 1991-1999 Nissan Sentra GA16DE 1.6L I4, the GA16DE's valve cover gasket and its spark-plug-tube seals harden and leak with age and heat cycles. Oil weeps down the outside of the engine and, more importantly, pools inside the spark plug wells where it saturates the plug boots and can cause misfires and rough running. A partial gasket-only repair often doesn't hold once the tube seals have hardened. Nissan vehicles past ~75,000 miles are noted as substantially more likely to develop these cover/gasket leaks.

On the 1991-1999 Nissan Sentra, as with most economy cars of this era in salt regions, the third- and fourth-generation Sentra/SE-R (B13 1991-94, B14 1995-99) develop structural and cosmetic rust. Enthusiast community 'trouble spot' guides for the B13 SE-R specifically call out terminal rust, saggy doors, and leaky sunroofs. Sunroof-equipped cars suffer plugged sunroof drain tubes that dump water into the headliner and floor, feeding floor-pan and rocker rust; rear strut tower/mount corrosion is also a known age issue on these unibody cars.

On the 1991-1999 Nissan Sentra, by age and mileage the Sentra's rear strut mounts, strut inserts, and suspension bushings are worn-out consumables. Community buyer's guides for the B13 note cars 'probably need a lot of new bushings, probably struts too,' and rear strut mounts are a routinely stocked replacement part across the 1991-1999 range. Worn mounts and bushings produce clunks over bumps, imprecise handling, uneven tire wear, and noise from the rear suspension.