Used Mercedes-Benz S300

What to know before buying: Mercedes-Benz S300

From 3 forum threads · updated 12/10/2026

What the reviews say

• An owner describes W140 engines and transmissions as very durable, but rates the bodies much less favorably.[2]one source
• S300 TD owner experience shows that fuel-pump seal work requires the correct tool and careful handling of small parts.[1]one source
• One W140 300 TD reportedly stalled while driving, restarted an hour later, then stalled again after a few minutes and would not start.[3]one source

Typical faults

• S300 TD injection-pump element O-rings and seals can leak fuel; the forum reports seepage at cylinders four and five.[1]one source

  S300 TD

• The black fuel-system unit with three hoses can leak; the forum says repair seals are unavailable, so replacement is normally required.[1]one source

  S300 TD

• An owner reports pronounced body corrosion on the W140 despite regarding its engines and transmissions as durable.[2]one source
• One W140 300 TD intermittently lost its warning lights, stalled and cranked without starting; the key or immobilizer was suggested as a possible cause.[3]one source

  300 TD

Which engine and version to take

• The best-supported choice is a well-kept W140 S300/300 TD: its engines and transmissions are described as durable, but the diesel fuel system should be dry.[1][2]

What to check at the inspection

• Inspect the W140 body and underside carefully for corrosion; owner experience identifies rust as a significant weakness.[2]one source
• When inspecting an S300 TD, look for diesel seepage around the injection-pump elements, especially near cylinders four and five.[1]one source
• Check the black fuel-system unit with three hoses; silicone residue or wetness may indicate a previous and recurring leak.[1]one source
• Start the car several times and let it run: all instrument warning lights should illuminate and the engine must not stall by itself.[3]one source

Verdict

Sources

1. [1]forums.mbclub.bg — S300 TD W140 - Страница 3 - Проблеми и ремонти · forum
2. [2]forums.mbclub.bg — Съвет относно закупуването на W140 S300. - Страница 2 · forum
3. [3]forums.mbclub.bg — W140 300 TD проблем! - Проблеми и ремонти · forum

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