deanyel is correct.

1993 300E's badged "300E" have the same 3.2 liter M104 engine (M104.992) found in 1994-1995 E320's. MB (in the U.S.) for some reason didn't change the badge until 1994, but in the rest of the world, 1993 300E's were badged as 320E's.

This 3.2 liter engine was also used in W210 chassis 1996-1997 E320's as well as 1993-1999 S320's (W140 chassis).

1993 models badged as 300E 2.8 have the same 2.8 liter M104 found in 1994-1997 C280's.

1990-1992 300CE's have a different M104 engien (M104.990). This 3.0 liter-24 valve M104 engine is an early version of the 24-valve DOHC 3.2 liter M104 engine used from 1993-on. The 3.0 liter version still used the CIS-E fuel injection system as 1986-1992 3.0 liter M103 engines, using a distributor with one coil wire and 6 spark plug wires. This is basically a mechanical injection system with electronic control.

The 3.2 liter M104 engine uses a different ignition system - HFM (hot-film mass air flow sensor), fully electronic with integrated electronic ignition and sequential fuel injection. This system combines fuel injection and ignition control in one module. HFM-SFI systems use coils that are mounted directly on the spark plugs, replacing the distributor at the front of the engine. Each coil pack provides spark to two spark plugs at the same time, one connected directly to one plug, and the other with a short high tension lead to the next spark plug. So there are 3 coil wires and 3 high tension lead wires.

HFM fuel injection systems are designed so that idle speed can't be adjusted. Idle speed is completely controlled electronically. This HFM injection system also has adaptive technology that compensates for conditions such as engine wear and unmeasured intake air and is designed to maintain driveability as the engine ages.

HFM-SFI can retard engine knocking to just the knocking cylinders, unlike EZL technology, which retards spark timing across the entire engine. This keeps the ignition timing point as advanced as possible for maximum power output.

The 3.2 liter M104 engines also have variable valve timing on the intake cam, making the torque curve broad and flat, developing HP at a much lower rpm. This makes the power much more useable and noticeable.

The problem with the M104 engine, in my opinion, is that they are more expensive to run. Why?

Early M104 engines had head gasket problems. Also, all 1993-1995 Mercedes have bad engine wiring harnesses. Last, M104 engines have an electronic throttle actuator which is notorious for failing. All three items are expensive to fix.

1992 300E's don't have the dreaded engine wiring harness problem, and also don't have a throttle actuator. Instead, they hava an idle control valve, which are not problematic.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".