Workshop Manuals Factory service & repair Geo

Geo common faults and how to fix them

Faults that are well known on Geo models we hold manuals for: what the owner notices, what causes it, and the pages in our manuals that cover the repair.

Geo Tracker rear axle recall: axle tube welds can fracture (1993–1994)

Symptoms

Often nothing is noticed before the weld cracks. In the worst case a rear wheel assembly separates from the axle, and the brake line to that wheel can break with it, so the car pulls and stopping distances increase.

Cause

NHTSA recall 94V073000 covers utility vehicles built by Suzuki, including the 1993–1994 Geo Tracker. The rear axle shaft housing tubes were incorrectly welded and can fracture. A fracture can let the wheel assembly separate, causing loss of control, and can also break the brake line, losing half of the braking system. GM ran its own Product Safety Campaign 94C22, reissued in August 1994 to cover more vehicles and to reinspect axles already replaced.

Fix

Dealers inspected the welds on the rear axle assemblies and replaced the complete rear axle where needed. On any 1993–1994 Tracker, check that the campaign was done, and look at the axle tube welds on both sides for cracks or rust when the car is up on a lift. The Geo Tracker rear axle campaign bulletin gives the inspection procedure.

Repair instructions on this site

Sources: NHTSA recall 94V073000; GM product safety campaign 94C22(a).

Geo Metro stalling: 1.0 stalls or loses power just after a cold start (1989–1992)

Symptoms

The engine stalls or loses power shortly after starting from cold. It can be made worse by revving the engine straight after start-up. Once warm, the engine usually runs normally.

Cause

GM bulletin 92-362-6A covers 1989–1992 Geo Metro models with the three-cylinder 1.0 engine, built before VIN breakpoints in 1992. High pressure in the hydraulic lifters can stop the valves from closing completely, because the lifters can't bleed oil off quickly enough during the cold start.

Fix

Check and reset the ignition timing and throttle position sensor to the manual's settings first. The Geo Metro lifters bulletin then checks valve spring length and force, the valve spring seats and camshaft lobe height. On engines built before the breakpoint, it replaces the hydraulic lifters with the revised type. A Metro that won't start or keeps stalling when cold is worth checking against this bulletin.

Repair instructions on this site

Sources: GM service bulletin 92-362-6A (August 1993).

Geo Prizm surging: engine surge or chuggle at highway speeds (1989–1990)

Symptoms

At steady highway speeds above about 45 mph, the engine surges or "chuggles". It may start with a light press on the accelerator or when coasting, and ranges from a single bump lasting a second or less to a bucking sensation that goes on for some time.

Cause

GM bulletin 90-443-6E covers certain 1989–1990 Geo Prizm models with the 1.6 engine, built within set VIN ranges. GM's correction points to the manifold absolute pressure (MAP) sensor and its wiring harness connector, which feed the engine computer the engine load signal it uses for fuelling.

Fix

The repair fits a new MAP sensor and a new MAP sensor wiring harness connector. GM covered it under a special policy that has long since ended. Before replacing parts, check the vacuum hose to the MAP sensor for splits and the connector for corrosion or loose pins. The Geo Prizm surging bulletin gives the procedure.

Repair instructions on this site

Sources: GM service bulletin 90-443-6E (special policy, April 1993).

Geo seat belt recall: front buckle release buttons can break (Metro, Tracker, Storm)

Symptoms

The red "PRESS" release button on a front seat belt buckle cracks or breaks. Pieces can fall into the buckle so that it doesn't latch properly, or it unlatches or jams.

Cause

NHTSA recall 95V103 covers passenger cars and multi-purpose vehicles fitted with seat belts made by Takata. GM's Product Safety Campaign 91C52 applies it to the 1989–1991 Geo Metro and Tracker and 1990–1991 Geo Storm. The plastic release buttons can break, and a buckle that doesn't latch properly won't protect the occupant in a crash.

Fix

Check both front buckles: insert each latch plate, tug the belt to make sure it is locked, then press the button and check that the latch plate pops out. Look for any cracks in the red button. If either button is cracked or a buckle doesn't work properly, have the buckle replaced; the Geo seat belt recall campaign gives the procedure.

Repair instructions on this site

Sources: NHTSA recall 95V103; GM product safety campaign 91C52 (May 1996).

Repair instructions for every Geo model: Geo workshop manuals