1983 Mercedes-Benz W123 300D turbo diesel

Summary:

A timeless, powerful, well built beauty, but it needs TLC

Faults:

Rough idle only at the start.

Typical oil leaks for this car.

Run on sometimes after the key is turned off.

General Comments:

Bought this car with 183K on it for $4500. Beautiful looking, and some light rust on the rear wheel wells.

Start right up, but idles rough for 10 minutes. Once on the road, it is very powerful and smooth. A real pleasure to drive, but it is over 30 years old, so is not engineered like we are used to today.

Good mileage; 33 MPG.

I love this car, and its classic looks are absolutely beautiful. Not perfect, and I expect it will keep me busy.

I have work to do on this vehicle, namely valve adjustment, diesel purge, rack damper adjustment, fluid filters (engine, trans, rear, power steering), track down oil leaks, vacuum review, body work... Etc etc.

I look forward to maintaining this car, and having it for many years.

Would you buy another car from this manufacturer? Yes

Review Date: 20th January, 2014

7th Jul 2015, 23:27

Mine has 97,875 miles on it. Outstanding original interior, needs a new paint job. Anyway your problem is probably one or more bad glow plugs.

21st Jan 2020, 02:18

I picked up a Blue W123 1983 300D turbo diesel for $300.

This was the 'fully loaded' last--year-model for the W123 chassis, sun roof, power everything. The only interior upholstery wear is on the driver's seat. Original floor mats. Original --everything--. About 300K on the clock, the odo cable blew out and I've yet to replace it.

The previous owners (AKA "IDIOTS") had parked it for well over a decade, covered in road salt, and the body is now un-repairable.

The drive-train, however, was nearly perfect. The brakes and the radiator were the biggies. Four wheels, three different models of brake caliper, and two totally destroyed disks. All four new, and same model now. Going is good. Stopping is better.

Scoured out the fuel tank, put in a new vacuum pump and secondary fuel pump, some brake lines and other hoses. New battery, flushed the crankcase, clean oil, clean fuel, and some fiddling to get the glow-plugs to work again. (Key switch is shot. There's a button on the lower-left of the knee-kick, driver's side, that fires the glow-plug relay now...)

Once it was all back in one big pile, it started after about twenty seconds of cranking, on a brisk 7C day (that's about 45F for the metric-impaired). Big puff of white smoke. Rattle-rattle-rattle for ten seconds, then the oil pressure was up and it has been running like a top ever since.

I had my buddy who owns a shop take it in and do the repairs as bits and pieces when his shop was otherwise idle. Took about a year to get it road-worthy again, but it was worth it. It will never LOOK good, but I drive it nearly daily, and use it as a great big tool-box.

I do odd job work for some local restaurants, now that I'm officially retired. Since they throw it away (recycler gets it for free), I have been known to scavenge 20 or 30 litres of used deep-fryer oil to mix into the rock-diesel from the petrol station. (Only during hot weather!!) It smells like tacos, or sometimes fish, going down the road, but I get upwards of 15 km per litre (that's about 35 miles per gallon, give or take).

I really love this old behemoth. Drives like a dream. I'd love to find a chassis and body with a blown engine, and swap the good parts from this one into it.

Anybody know where one might be found??

21st Jan 2020, 18:23

You'd need to try eBay or Mercedes/classic car community specialist websites, and expect to travel far to find the perfect car. I like these old Mercedes also.

1983 Mercedes-Benz W123 300D 3.0 liter 5-cylinder turbo diesel

Summary:

It would be a great car for a first time driver, or for someone who is in no hurry

Faults:

Key stuck in the ignition due to steering wheel locking mechanism failure... common at around 300000 miles. Required some minor dash removal, a new key, tumbler, extraction of the wheel lock, some grinding and pounding, but it is better than new.

I accidentally started the car with no way of turning it off (no ignition switch installed). Can't pull the plugs, the battery, the coil wire, etc. as there are none. Even pinching the fuel lines was absurd. I was freaking out.

General Comments:

Comfortable, safe, although this is my 2nd, and both cars had the same ignition switch problem, and this one has the vacuum door locks not working, no dash lights, no overhead light, and no heater/ventilation unit working.

Would you buy another car from this manufacturer? Yes

Review Date: 6th June, 2012

8th Jan 2020, 21:21

There should be square or diamond shaped lever near the top of the engine (pretty easy to see) with a stop sign at the top, says 'ENGINE STOP'.

Press this lever down (at the red sign) towards the engine and hold it down and the engine *should* stop. Saw a YouTube video about restoring an old I want to say 1983 Mercedes 300D (YouTube poster is called "mercedessource", all one word) and he had to do this to check the engine for a suspected misfire.

p.s. Of course wear gloves and exercise caution, the engine may be hot!

Happy motoring!