Purchase of mercedes 1987 300td



I plan on buying a 1987 mercedes 300td with 120,000 miles original owner died and widow is selling. Car has sat for 6 months (garaged at all times since new)and driven very little the last two years. All maint. done routinely until two years ago. What should I replace or update pror to putting in full time use. What were problem areas with this car? Thanks


Fuel and filter will be an issue.
Glow plugs may need replacement.
Valves may need adjustment.
Do you get the full maintenance history?

Also, have you checked if the various electrical accessories work? And the AC on these can be a problem.

Of course, you have all the normal issues to check on a 23-year old car, too.


Fuel NOT an issue. Diesel fuel does not degrade like gasoline. Charge the battery, pump up the tires and GO! 120K miles is not bad. The only real problem with this and all Benz cars is the COST of maintaining them. You can learn to do most of it yourself. Rust in the lower body can be a problem…Pull up the carpeting and check the foot-wells for rust-through…


Agree with above comments. If you were given this car, it would still be expensive to own. I would decide first if I was the type of person who could live with nursing a 23 year old car that will definitely be difficuult to keep running and get parts for at a reasonable price.

If you live in an urban area with several Mercedes dealers, there will be wrecking yards that have parts, keeping down the cost.

A retired engineer or mechanic is the perfect person to own such a car.

Whatever you do, don’t pay much for it.

Unlike later Mercedes cars, these models had few design problems and many served as taxis for up to a milion miles. You will mostly be dealing with age-related problems.


First, review all the maintenance records and receipts you can find. Put them in order of date or odometer miles and start to piece together the maintenance history of the car. Some people consider an oil change the full extent of maintenance.

On the car I’d start with replacing every fluid and filter unless you have a documented record less than 3 years old that the fluid in question was changed. Even though this diesel has a turbocharger don’t expect rocket performance. The car will get up to speed and hold speed and should be comfy but not quick. You can expect to see some big clouds of black smoke from the tailpipe, especially when you get on the gas hard. That is normal, as is some soot on the rear bumper near the exhaust.

Hopefully the turbocharger is OK, if it is make sure to do oil changes as per mfg recommendations. As a turbodiesel you’ll need to use the quality of oil also as per mfg recommendations. If a full synthetic is compatible with a diesel I’d go with a full synthetic. Turbochargers need good quality fresh oil if you expect it to last and a new one for this MB would be costly.

All the rubber hoses and tubes are 24 years old so inspect and replace any that have dry rot or feel soft. I believe the car was generally reliable, but at 24 years old whether it will remain reliable is doubtful. You should have a back up car for when this one is “down”. Not all mechanics can work on it so you’ll need to find a qualified mechanic. Then budget for repairs, say $1,000 to 2K per year. Good luck.


Fuel could be 2 1/2 years old. May not be an issue, but could be.


I love that car, and if you look around you will see that they’re still being sold with over 200k for more than $5000. They’re coveted because I think that’s the only year they made that car with the turbo 6cyl.

You can get OEM parts really cheap at autohausaz.com, they get their parts from worldpac which is owned by CarQuest. My local CarQuest will match online prices and can get it to me usually the same or next day. I have a '78 Mercedes diesel with 300K and its still the most reliable car i’ve ever owned.

I would do basic maintenance (oil change, fuel filter, air filter,…) maybe do a diesel purge service but definitely flush the cooling system and replace with Mercedes coolant - I would also inspect the rubber boots and bushings in the suspension and make sure they’re in good shape and not all cracked and dried. - that could be dangerous if not in good working order.

buy it! and enjoy


Our better mechanics have covered the repair issues, etc.

My suggestion is to evaluate what you expect from this car. If you expect a car that old to run and run with little or no cost or work, you will be disappointed.

If you want to drive something different from anything you have driven, and don’t mind some expense and work, this could be fun.


This is the six cylinder diesel engine, not the bullet proof five cylinder of 1985 and earlier.

This engine has definite problems with cracked heads, and it’s an expensive fix. If the head has been updated it should be OK, otherwise the repair will cost close to the cost of the car.

Otherwise the updated 124 chassis makes for a timeless design, and holds up well.