1999 GMC Yukon Problems
RepairPal has identified the most common problems with the 1999 GMC Yukon based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
The upper dash may crack, most commonly on vehicles in warm climates and exposed to a lot of sunlight. The common repair is to replace the upper instrument trim panel. Information on a technical service bulletin or extended warranty is not available at this time.
The power door lock actuators may become slow to operate or stop working completely and require replacement.
The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.
Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
The inside and outside door handles are prone to breaking.
The 99-01 GMC Yukon has a known issue with the air pump check valve which causes illumination of the check engine light. There are no notable symptoms, but the vehicle will not pass state inspection or smog testing.
When the valve fails, it sticks closed, and the computer sets the code P1416. Replacement of the check valve is the only fix, as the valve is not serviceable.
The headlight switch used on the GMC Yukon is known to fail through normal operation. Since the headlight switch is also integrated into the interior lights, a malfunctioning switch can cause issues with interior lights as well.
- Symptoms of a failed headlight switch include:
- Headlights and taillights failing to turn on or off
- Interior lights flicker, or fail to turn on or off
- Gauge cluster lighting off or flickering with headlights on
- Parking light malfunctions
This issue is well known with General Motors Trucks and SUVs, and is solved by testing and, if needed, replacing the headlight/dimmer switch. Bad grounding wires at the tail-lights, and dirty/corroded tow package wires can also lead to some of these issues.
The engine may develop a misfire due to worn valve seats. This fault will cause the Check Engine Light to illuminate. Our technicians tell us the misfire may or may not be felt while driving. They further recommend that both cylinder heads be removed and thoroughly inspected and repaired as necessary.
The front or rear differential may develop an abnormal noise due to worn bearings or another internal fault. Our technicians tell us that a complete overhaul of the affected differential is commonly necessary to correct this condition.
One or more fuel injectors may become stuck closed causing an engine misfire and the Check Engine Light to illuminate. Our technicians tell us that this problem can be caused by some fuel additives. There are special procedures which may be able to restore the affected injector. If this fails the affected injector must be replaced.
The spark plugs should be replaced every 100,000 miles. Our technicians recommend replacing the spark plug wires also at this time.
The quick-connect fittings for the heater hoses tend to leak engine coolant. This problem commonly occurs because the metal housing has become brittle, which can break and cause leaks.
A coolant leak may develop from the water pump. This can result in an engine overheating condition. A leaking water pump will require replacement.
Vehicles equipped whit a 4 speed automatic transmission may develop a harsh 1-2 shift and/or illumination of the Check Engine Light with code P1870 stored. This can be caused by wear of the bore for the TCC isolator and regulator valves in the valve body. This condition does not commonly occur until the transmission reaches normal operating temperature. If the valve body is worn, replacement will be necessary to correct this concern.