Dodge Omni/Horizon/Rampage 1978-1989 Repair Guide



There are three different engines used in these body styles. The 1.7L, basically a Volkswagen design, is used during the 1978 thru 1983 model years. The 2.2L engine, a Chrysler refined version of the 1.7L engine was introduced during the 1981 model year. In 1984 the 1.6L engine was introduced to replace the 1.7L engine. Below is a description of each of these engines.

The 1.6L displacement engine is a four cylinder overhead valve engine with a cast iron block and an aluminum cylinder head. Five main bearings support the forged steel crankshaft with number three being the thrust bearing. The cast iron dual timing chain sprocket on the crankshaft, not only provides power for the timing chains, but it also acts as a vibration damper. The cast iron camshaft is mounted on three babbitt bearings and a thrust plate located at the front bearing controls the camshaft end-play. The camshaft itself is positioned left of the crankshaft, or toward the front of the car. The camshaft is driven by dual timing chains. These chains are enclosed by a cast aluminum timing cover which has the strobe ignition timing marks embossed on it. The cylinder head material is an aluminum alloy. The head is a crossflow design with inline valves. The valve train design incorporates the use of mechanical tappets, pushrods, and adjustable rocker arms. The spark plugs are located on the left side of the engine opposite the valves. The intake manifold is made of a cast aluminum alloy, cored with coolant passages for carburetor warm up. This manifold is located on the left side of the head. Embossed on the intake manifold is the cylinder number identification, firing order, and the direction of the distributor rotation. The exhaust manifold is made of nodular iron and is attached to the right side of the head (towards the rear of the car) and is held on by eight bolts.

Click image to see an enlarged view

Fig. Fig. 1 Cut-away of the 1.7L engine

The 1.7L displacement engine is a four cylinder, overhead camshaft engine. The block is cast iron and the head is aluminum. A five main bearing forged steel crankshaft using no vibration damper is employed, rotated by cast aluminum pistons. A sintered iron timing belt sprocket is mounted on the end of the crankshaft. The intake manifold and oil filter base are aluminum. A steel reinforced belt drives the intermediate shaft and camshaft. The intermediate shaft drives the oil pump, distributor, and fuel pump. The cylinder head is lightweight aluminum alloy. The intake and exhaust manifolds are mounted on the same side of the cylinder head. The valves are opened and closed by the camshaft lobes operating on cupped cam followers which fit over the valves and springs. This design results in lighter valve train weight and fewer moving parts.

Click image to see an enlarged view

Fig. Fig. 2 The 2.2L engine used on some models covered by this guide

The 2.2L displacement engine is a four cylinder, overhead camshaft design powerplant with a cast iron block and an aluminum cylinder head. The cast iron crankshaft is supported by five main bearings. No vibration dampener is used. The iron camshaft also has five bearing journals and there are flanges at the rear journal to control the camshaft end-play. Sintered iron timing sprockets are mounted on both the camshaft and the crankshaft which are driven by the timing belt. The timing belt also drives an accessory shaft, housed in the forward facing side of the block. The accessory shaft, in turn drives the fuel pump, oil pump and the distributor. The engine oil filter is attached to the base located at the left front of the block, toward the front of the car. The intake manifolds are cast aluminum and the exhaust manifolds are iron, both of which face the rear of the vehicle. The distributor, spark plugs and oil filter are all located on the forward facing side of the engine.