Gmc GM 4.3L Vortec V6

Gmc GM 4.3L Vortec V6 — every model and year that used this engine (21 models, 1985–present), based on NHTSA VIN build data, with links to prices and reliability.

Sierra, Sonoma, Savana.

4.3L · 6 cylinders · seen in 21 models, 1985–2026

By the numbers

Gasoline: 99%. Based on 789 decoded NHTSA VIN build sheets.

About this engine family

The Chevrolet 90° V6 family of V6 engines began in 1978 with the Chevrolet 200 cu in (3.3 L) as the base engine for the all new 1978 Chevrolet Malibu. The original engine family was phased out in early 2014, with its final use as the 4.3 L (262 cu in) V6 engine used in Chevrolet and GMC trucks and vans. Its phaseout marks the end of an era of Chevrolet small-block engine designs dating back to the 1955 model year. A new Generation V 4.3 L (262 cu in) V6 variant entered production in late 2013, based on the LT1 small block V8 and first used in the 2014 Silverado/Sierra 1500 trucks.

In detail

These engines have a 90° V-block with twelve valves activated by a pushrod valvetrain. All engines have cast iron blocks and cylinder heads. The engines are based on the Chevrolet Small-Block engine, and the V6 is formed by the removal of the 3 and 6 cylinders. The V6s share the same bore spacing and deck height as the V8 engines. Many parts are interchangeable between the 90° V6 and the small block V8 including valvetrain components, some bearings, piston assemblies, lubrication and cooling system components, and external accessories.

The 90° V6 engine uses the same transmission bellhousing pattern as the Chevrolet small-block V8 engine. The oil pan dipstick is located on the passenger side above the oil pan rail; this design was phased in on both the 90° V6 and Small Block Chevrolet assembly lines (for engines manufactured after 1979) sharing the same casting dies. All the engines use a 1-6-5-4-3-2 firing order. The engines in this family are longitudinal engines, and have been used in rear-wheel drive cars and trucks, industrial, and marine applications.

Until 2014, the Chevrolet 90° V6 was produced at the GM Powertrain Division plant in Romulus, Michigan. Introduced in 1978, the replaced the larger as the base engine for Chevrolet's new downsized intermediate line. The used a unique bore and stroke (the Chevrolet V8 engines shared the same stroke dimension). These bore and stroke dimensions were later used by the V8 Chevrolet engine. Also like the small block V8 engines, the V6 used main bearings and rod bearing diameters.

Being a 90° V6, Chevrolet took steps to eliminate the rough running tendencies of the 200. The crankshaft has each of its connecting rod throws offset by 18 degrees for each pair of rods. This required the connecting rods to have narrower ends as well as a thrust bearing to be installed between each pair of rods. However, the connecting rods were still the same length as most other small-block Chevrolet V8 engines. This produced an engine with a semi-even fire sequence of 132 degrees/108 degrees.

The V6 was only produced for 1978 and 1979. It was available only with a 2-barrel carburetor. In 1978, the used the Rochester 2GC carburetor and in 1979 it used a Rochester Dualjet carburetor. The smaller Dualjet carburetor caused a slight decrease in power. The engine was first introduced for the 1980 model year. This engine replaced the straight-six in full-size Chevrolets and Camaros as the base six-cylinder engine.

Additionally, the intermediate Chevrolet Malibu and Monte Carlo also used the as a replacement for both the V6 and the Buick V6. Checker Motors Corporation also used this engine starting with its 1980 A11 Taxi and A12 Marathon sedans. Both the Buick V6 and the Chevrolet V6 are 90° V6 engines, and are often referred to as the 3.8L V6. These engines should not be confused as being the same, and are unique engine designs.

The has a bore and stroke, identical to the Chevrolet V8 engine. The used the same main bearing and rod bearing diameters as the V6 engine. Also like the V6, the used the same crankshaft with the 18-degree offset throws and the same connecting rods with narrowed ends. It came equipped with intake valves and exhaust valves. The V6 was only equipped with a 2-barrel carburetor. For 1980, the used a mechanical Dualjet. From 1981 to 1984, the electronic Dualjet was used along with the GM's CCC (Computer Command Control) system.

The was rated between 110. The V6 is the last and most successful engine in the Chevrolet 90° V6 engine family. This engine was introduced in 1985 as a replacement for the V6 in the full-size Chevrolet, the Chevrolet El Camino, and Chevrolet Monte Carlo. It also replaced the in the Chevrolet and GMC full-size trucks and full-size vans, and in 1990, it replaced the 292 cu in (4.8 L) in the Step-Vans as the new base six-cylinder engine.

The V6 has a bore and stroke, identical to the Chevrolet V8 engine.

Source: Wikipedia — General Motors 90° V6 engine, CC BY-SA.

Models that used this engine

Model Years with this engine Fuel VIN builds seen
SIERRA 1989–2021 Gasoline 210
SAVANA 1996–2026 Gasoline 171
SAFARI 1985–2005 Gasoline 132
SONOMA 1991–2004 Gasoline 121
JIMMY UTILITY 1995–2005 Gasoline 37
S15 UTILITY 1988–1994 Gasoline 28
S15 PICKUP 1988–1990 Gasoline 18
VANDURA 1985–1995 Gasoline 16

Engine usage derived from NHTSA VIN build data (displacement + cylinder configuration). Model links lead to prices, generations and reliability.

For sale with this engine