1998 model year · 0+ owner reports · Updated April 2026
According to Au7o's analysis of 0+ owner reports, the 1998 GMC Suburban has 4 documented known issues. No issues are rated critical, indicating generally reliable ownership. Across all issues, repair costs range from $150 to $2,000. DIY maintenance guides at au7o.io.
On the 1996-1999 GMC Suburban, the in-tank fuel pump works harder due to the Suburban's large fuel tank (42 gallons) and fails prematurely. The pump draws more current to push fuel the longer distance to the engine, leading to burnout.
Replace fuel pump module assembly (Delphi FG0100). The large tank makes this job more involved - support the tank properly during removal. Replace the fuel filter (frame-mounted) at the same time.
Parts and tips from 0+ owners who fixed this issue
On the 1996-1999 GMC Suburban 5.7L Vortec, the GMC Suburban shares the same 5.7L Vortec intake gasket and spider injector issues as the C/K 1500. The larger vehicle runs hotter, which can accelerate gasket degradation.
Pressure-test the cooling system and inspect for external seepage at the lower intake manifold gasket, then scan fuel trims/misfire data and remove the upper plenum to check the Central Port Injection (CPI) spider for fuel leakage or sticking poppets. Repair typically involves replacing the lower intake manifold gaskets with the updated metal/rubber design, changing coolant and engine oil if contaminated, and torquing the intake in sequence to spec; if the CPI unit is leaking or causing hard starts/rough idle, replace it with the updated MFI spider assembly. Parts are usually about $120-$250 for intake gasket sets and $250-$450 for the injector assembly, with total repair costs commonly running $900-$1,800 depending on labor rates and whether both problems are addressed together.
Parts and tips from 0+ owners who fixed this issue
On the 1995-2006 GMC Suburban, the GMC Suburban (and Chevrolet Suburban/Tahoe/Yukon) with rear AC systems develop leaks in the rear evaporator core and the aluminum rear AC lines that run along the passenger-side frame rail. The lines corrode under the securing straps from road salt and moisture. The rear drain tube also clogs, causing musty odors inside the cabin. Repair is costly because the rear AC system is difficult to access.
Confirm the leak by recovering the refrigerant, pulling the system into vacuum, and pressure-testing with dry nitrogen and UV dye or an electronic leak detector at the rear evaporator case and the aluminum lines running along the passenger-side frame rail, especially under the retaining clamps. Replace any corroded rear lines and, if leaking, the rear evaporator core and O-rings, then flush debris, evacuate the system, recharge to factory specification, and clear the rear evaporator drain tube to stop water intrusion and mildew odor. Many owners in rust-belt areas choose a rear A/C line delete or block-off kit if rear cooling is not needed, which is cheaper than full line replacement. Typical cost is about $400-$900 for line repair/delete, or roughly $1,200-$2,000+ if the rear evaporator core and interior trim access labor are required.
Parts and tips from 0+ owners who fixed this issue
On the 1992-1999 GMC Suburban, the rear heating and A/C system suffers from blower motor failure and rear heater core leaks. The rear heater core is located under the rear cargo area and is susceptible to coolant corrosion.
Replace rear blower motor (VDO PM3542) and/or rear heater core. The rear heater core requires removal of rear cargo panels for access. Flush the cooling system and use proper coolant mix to prevent future corrosion.
Parts and tips from 0+ owners who fixed this issue
STRUCTURE
CERTAIN PICKUP TRUCK, VAN, AND MINI VAN CONVERSIONS EQUIPPED WITH SOUTHERN COMFORT BUILT RUNNING BOARDS THAT CONTAIN CERTAIN COURTESY LIGHTS MANUFACTURED BY AMERICAN TECHNOLOGY COMPONENTS, INC. THESE UNITS CONTAIN A COURTESY LIGHT OR LIGHTS THAT MIGHT OVERHEAT WHEN THE WIRE HARNESS IS EXPOSED TO EXCESSIVE MOISTURE AND ROAD SALT.
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According to Au7o's analysis of 0+ owner reports, the 1998-1998 GMC Suburban has 4 documented issues. The most frequently reported are: Fuel Pump Failure in Large Tank, 5.7L Vortec Intake Manifold Gasket and CPI Issues, Rear AC Evaporator Core and Line Leaks. None are rated critical, but regular maintenance is recommended.
The 1998-1998 GMC Suburban has 4 known issues documented across 0+ owner reports. No issues are rated critical, suggesting generally good reliability. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known GMC Suburban issues range from $150 to $2,000, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
The in-tank fuel pump works harder due to the Suburban's large fuel tank (42 gallons) and fails prematurely. The pump draws more current to push fuel the longer distance to the engine, leading to burnout. Repairs typically run $350-$700. Severity: medium.
The GMC Suburban shares the same 5.7L Vortec intake gasket and spider injector issues as the C/K 1500. The larger vehicle runs hotter, which can accelerate gasket degradation. Repairs typically run $500-$1,200. Severity: medium.
The GMC Suburban (and Chevrolet Suburban/Tahoe/Yukon) with rear AC systems develop leaks in the rear evaporator core and the aluminum rear AC lines that run along the passenger-side frame rail. The lines corrode under the securing straps from road salt and moisture. The rear drai… Repairs typically run $600-$2,000. Severity: medium.
The rear heating and A/C system suffers from blower motor failure and rear heater core leaks. The rear heater core is located under the rear cargo area and is susceptible to coolant corrosion. Repairs typically run $150-$600. Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
