Hi Mike and thanks for the Technician tip. I have a family friend in sales at FMW that does not know that I have this car let alone this problem. I will call this tech and ID the source unless you would prefer that I did'nt.

The following is an excerpt from some tech writer that sounded like he knew what he was doing as I recalled from following this vehicle since it's debut in 1992.

In 1990, Mercedes decided to develop a high performance version of their successful 300E model, which debuted in 1986. Porsche was contracted to engineer the modifications necessary to transform an ordinary 300E into the very special 500E. However, the extensive modifications to the floor and external sheet metal meant the 500E could not easily be built on the normal assembly line at the busy Mercedes Sindelfingen plant. So, Mercedes also called upon Porsche to perform the assembly of the 500E at Porsche's Rossle-Bau plant in Zuffenhausen. The contract called for 8 to 12 500Es per day, 2400 per year, built to the highest quality.

During the 1992-1994 production run, Porsche's Rossle-Bau facility was operated by Old World standards: cars were built on wheeled pallets and were moved by hand from station to station as they were assembled. Electric spot welding was also done mostly by hand. This process is a major reason why I would place a special value on the 500E, as no other modern-day Mercedes has received so much care in assembly and quality control.

Each 500E started life at the Rossle-Bau plant where the basic body shell was completed, including doors, trunk, and hood, and then transported on special trucks to the Mercedes Sindelfingen plant across town. There, the body was corrosion-proofed and painted, giving it the full measure of rust protection and allowing customers to choose from the entire palette of Mercedes colors. Then each 500E went back to the Porsche plant for more assembly. Engines, transmissions, and other major mechanicals were assembled by Mercedes and shipped to Porsche for installation. Then another trip across town, back to Mercedes, where each 500E received a final inspection before delivery or export. On average, it took 18 days to build each 500E, much of which was consumed by transportation time.

Porsche's modifications to the original 300E included splaying-out and reinforcing the frame rails, widening the drive shaft tunnel, modifying the front axle cross member and other engine bay components to accept the 5-liter 322-hp V8 engine that was also specified for the 500SL at that time and weighed 70 lbs more than the 300E's inline-6 engine. The heavy duty battery was moved to the trunk to achieve an ideal 50:50 weight balance with two occupants and 175 lb of luggage aboard. 500SL-sourced wishbone suspension pieces and steering linkages were reinforced to accommodate the 500E's increased weight. The 500E stands nearly an inch lower than the 300E due to shorter and stiffer springs with plastic buffers and gas pressurized shock absorbers with internal damping springs. A hydraulic self-leveling suspension is standard equipment. 11.8-inch vented disc brakes in the front were sourced from the 300CE, and the 10.9-inch vented rear discs were the same as the 500SL. Wider wheels and tires resulted in a 1.5-inch wider track, and the wheel well fenders were flared out to better accommodate the extra width.

While the 500E's engine was the same M119 V8 used in the 500SL, the 500E was specified with Bosch LH Jetronic fuel injection (the 500SL used KE Jetronic) and a redesigned intake manifold with longer runners that resulted in an additional 22 lb-ft of torque, developing a maximum 354 lb-ft at 3900 rpm.

To handle the extra horsepower and torque, the 500E's 4-speed automatic transmission was sourced from the 500SL model, as well as its rear axle that used a 2.82:1 differential to fully exploit the V8's torque. ASR traction control was standard and no defeat switches were provided by the factory (aftermarket defeat switches are available, however). Like all other Mercedes transmissions at that time, the default starting gear was 2nd, presumably to ensure smooth acceleration. There were two ways to force a start in 1st gear: either floor the gas pedal, which resulted in a less-than-smooth kick down, or by moving the gear selector down and over to B, then back to D (this tricked the gearbox into starting off in 1st, regardless of throttle position).

Factory performance figures were 0-to-60 mph in 5.6 seconds and a top speed of 155 mph. With the standard ASR, most real-world acceleration runs produced 6.0 to 6.2 second results. With ASR defeated via aftermarket equipment, sub-6 second times would be more reliably achieved. The 155 mph top speed was electronically limited, in accordance with the Audi/BMW/Mercedes agreement to avoid escalating top speed wars.

The 500E's competition was the BMW M5 and Audi S4 (not to be confused with the 2000 S4 which is a high performance version of the A4; the 1992 S4 was a high performance version of the then 100/200 model, now A6 model). The M5 was typically more desirable to track enthusiasts because of its standard manual transmission (no automatic was offered) and beefy inline-6 engine. The S4's standard Quattro four wheel drive appealed to all-season sport sedan owners. But the 500E was the king of the autobahn with its torquey V8 engine and tank-like build quality. The kind of driving fun you experience in the 500E is not the sort of tail-out tire-smoking session you could have with an M5, but rather an impressive display of smoothness and effortless power delivery and road holding grip that can only fully be appreciated on the long, winding, high velocity roads of the Autobahn and Autostradas of Germany and Italy.

The 500E had few faults. The single windshield wiper arm, although engineered to clear most of the windshield with each stroke, cannot compensate for high-speed duty. The climate control system was not very friendly to use, and not very accurate in keeping the cabin at a steady temperature. And, as already mentioned, the ASR was non defeatable (Mercedes has since offered ASR defeat switches in its high performance models beginning around 1995).

The 1992-1994 Mercedes 500E is truly special because of its unique involvement with Porsche, something no other Mercedes model can claim, past or present. That distinction alone makes the 500E desirable to both Mercedes enthusiasts and Porsche enthusiasts. And unlike the AMG Mercedes models of today, with their attention-getting 18-inch 5-spoke wheels and sculpted lower body panels, the 500E looks nearly identical to its plebian 300E sibling, truly defining the old adage "a wolf in sheep's clothing".


If this guy is wrong Mike, I would certainly like to know that and correct my data files on the 500E/E500.

Tom