Mercedes W124 E500/500E Buyers Guide

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Jan 25, 2014
Nuneaton, Warwickshire
Lots of Mercedes!
Hi All,

Over the years I have written some buyers guides for the popular magazines. I thought they may help here.

I hope these is no issue with that.

If there is anything wrong, please dont hesitate to correct me. The final printed versions were heavily scaled down by the magazines. These are my raw words and my opinions based on my experience only.

The 500 used a variant of the proven M119 engine. Overall this engine has a fantastic reputation for reliability and longevity. We very rarely see failures of these engines and can rack up hundreds of thousands of miles.
Like any engine, maintenance is key and there are some common issues with the engine.
The 500’s were manufactured during the era of biodegradable wiring looms. At this age they have all but biodegraded and so require replacement. The symptoms of this issue are non start, poor running and other engine related electrical issues such as misfires. The issue is very easy to spot by looking closely at the wires where they plug into sensors or components. If the inner insulation is cracking, it has likely not been replaced. There is an upper and lower wiring harness, both should be replaced for peace of mind. Any car that hasn’t has this work done, should have it done as a matter of urgency. If left unattended, damage to other electrical control units is likely.
Electronic Throttle Actuators and Mass Air Flow Sensors are two common failures. The Electronic Throttle Actuator also suffers from crumbling wiring and this should be checked. The Mass Air Flow Sensor will cause a lack of performance when it becomes faulty.
The distributor caps and rotor arms are known to fail regularly. There are two of each. This will be evident if the car is misfiring or idling poorly. In my experience, these should be changed every third service to ensure trouble free motoring. There are two distributor caps and two rotor arms. Parts are available aftermarket and we always recommend either Bosch or Beru branded parts if Mercedes prices are too much to stomach.
Timing chains are duplex on this engine and rarely fail. At mileages of over 150K, it would be good preventative maintenance to replace the chain, tensioner and guides. Not a cheap job but this will ensure the continued smooth running of the engine. If you hear any rattle on startup the chain should be replaced immediately.
The M119 chain also suffers from failed cam oiler tubes. These are plastic tubes that supply the cam shafts with lubrication. Any tapping from the cams is normally due to these oiler tubes. This job will run to around £600 at an independent garage.
The cooling system should be working efficiently. The vehicle temperature should never approach the red area. An efficient cooling system will keep the temperature well under the 100 degree mark even on the hottest day. Most of the time it should stay at around 85 degrees. Viscous fan couplings, radiators and water pumps are common issues. We recommend using only genuine parts if replacing these essential items. An overheating car will quickly cause severe damage to the engine so any issues should be rectified without delay.

The exhaust system is well made and have been proven to last 15-20 years. At this age the system should be inspected for leaks. Parts are still available from Mercedes.
Many owners choose to replace exhaust systems with custom made stainless steel items, which usually come with a lifetime guarantee and are cheaper than buying a genuine system.

The transmission on the 500E is very strong and well proven. Of course over the years the gears and clutches can wear. Any potential buyer should check that the gear changes are silky smooth and there are no harsh clunks when selecting gear.
We recommend regular transmission fluid and filter changes, at least every 40K miles. Cost would be circa £200 at an independent.

The 500E shares many suspension components with the standard W124, although hydraulic rear self levelling is standard across the range. Front shock absorbers are a serviceable item and are not expensive. Various aftermarket options are available.
Front Lower suspension arm ball joints are a wear and tear item that should be checked for excess play. This requires replacement of the complete suspension arm. These should be replaced in pairs. A garage should charge between £7-800 for this work using good quality parts.
The rear suspension is a little more complex and does require close examination. The pipework should be examined for corrosion. These, like brake pipes, can corrode and leak. The pipes are available from Mercedes, however fitting some of the lines around the rear axle takes time and patience.
Rear suspension spheres are a common replacement item which will cause a bouncy uncomfortable ride. These are approximately £200 each from Mercedes. Including fluid and fitting charges, this is around a £600 job. Aftermarket parts are available a little cheaper. Once this job is done, the car should not need them replaced again for at least 100K miles.
The rear shock absorbers have been known to become noisy or leak. Replacement is straight forward but they are pricey. Aftermarket items are around £350 + VAT each.
Due to age, all of the various ball joints and suspension links should be examined closely. The rear lower ball joints in particular are often missed during inspections however they are prone to fail, causing a knocking noise. Special tools are required for this job and a garage would likely charge £300 per side for this work. The five link rear suspension is also worth replacing if it has not had any attention. All the arms/links are available and not too pricey individually, however to complete a refresh of both sides would cost around £800 using genuine parts.
Wheel bearings should be checked for excess play. Front bearings can be adjusted. Rear bearings cannot be adjusted and replacement is a labour intensive job.

Brakes and wheels
The 500E uses the brakes from the R129 series. Early 500E’s have 300mm front brake discs. Many owners complain of poor braking performance with this setup. In 1993 Mercedes changed to a 320mm brake disc which improved the situation.
A common upgrade amongst owners is to install 334mm brakes from a R129 Silver Arrows. These larger brakes with high performance Brembo callipers improves the braking of the 500E immensely.

As with any twenty plus year old car, corrosion is an issue. Front wings are made from heavy guage steel and even if they exhibit some paint bubbles, the rust can normally be ground back and repaired. New wings are now over £1200 from Mercedes and therefore well worth restoring if possible.
Rust around the wheel arches is common, again a good bodyshop should be able to repair any affected areas. It is important to examine the car thoroughly for rust, especially on the underside.
We recommend wax protection in order to keep the underside and suspension rust free.
Some of the 500 specific plastic side cladding panels are no longer available. If these are missing on a car, finding replacements is extremely difficult.
Many owners “facelifted” early cars with bonnet and boot lid from later models. If you want an original car then pre 1993 cars should have the larger chrome grille and recessed number plate panel on the boot lid. Later cars had the chrome grille inset into the bonnet and a flush number plate panel on the rear. Pre/Post Facelift cars have many other subtle differences including colour coded bumpers, different headlamps, rear tail lamps and indicators.
A full respray will run into many thousands depending on level of corrosion, therefore it is very important to check the car over in this respect.

The electrics on this model do not generally cause many issues. The engine wiring harness is the major concern which, I have mentioned above.
It is important to check the function of every component. Items can fail due to age and although most items are available from Mercedes, prices are not always palatable.
Seats should be checked for all of their functions, electric windows should be fast and smooth. Sunroof should glide back without any nasty noises.
The Air Conditioning system should be examined for proper function. Due to age, leaks in the system are common and electrical such as the fan switches components can fail. The most likely leak point is the condenser, this is available from Mercedes. Cost of replacement will be around £800 from an independent garage.

Parts supply
Mercedes offer most items for these vehicles from stock. However many 500 specific items are now becoming obsolete or prohibitively expensive. Items such as body panels, trim pieces and so on are difficult to find.
The common service items are available, mainly due to the fact that they are shared across other models of Mercedes.

Whilst we always recommend Mercedes genuine items, good aftermarket alternatives can often be just as good with a lower price tag.

Minor service


Major service


Gearbox service


Front brakes ics and pads
Depending on year, between £250-350

Engine mounts

£700 using genuine parts

Distributor Caps & Rotor Arms:

£650 using genuine Mercedes parts

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