what to look for when checking out a used diesel mercedes? - PeachParts Mercedes-Benz Forum

psranga · #1 09-29-2006, 09:38 AM

Hello all,

I have done the preliminary checking of several cars and narrowed it down to two after eliminating the obviously unappealing cars. Now, I would like examine these two cars in detail before finally making an offer.

1. Is there a checklist of what to look for when examining a used diesel
Mercedes?

2. Is there a reliable mechanic in San Francisco who I can call on to do the
examination for me.

3. The cars being considered are:

1983 300SD Turbo Diesel 190K miles
1982 240D 236K miles

4. The 300SD shifts hard from first to second during hard acceleration.
Is that a problem?

5. What are the common problems that are expensive to fix that crop in
these cars after 20 years or so?

Thanks a ton. This forum is awesome!

Ranga

greasybenz · #2 09-29-2006, 11:04 AM

Not in SF but ive found a good mechanic in walnut creek that is very familiar with MB diesels. Look it up on yellow.com, his shop is called kirks motorsport and its in walnut creek.

My uncle works at bay area alternators in SF which is a european car repair shop but he isnt to familiar with MB diesels. Youd have to tell him what you want done and he can do it.

My suggestion, if your looking into getting either one of these cars its best to learn how to do the work yourself. Otherwise buy a newish C-class benz or a toyota. They are more reliable, these cars require a good amount of work and $$ to stay running correctly.

The shifting is most likely a vacuum issue and can be fixed.

rrgrassi · #3 09-29-2006, 11:24 AM

See if you can go over ALL the records, if available.

Check for blow by.

Look at the condition of the drive belts.

Look at the levels and condition of all fluids. Look under the car for drips and or puddles.

Start the engine and listen for any odd noises.

If possible, raise the car up to relax the suspension and check for movement in things that should not be moveable, and also try to wobble the wheels from top to bottom. There should be no movement. Spin the wheels to make sure the bearing feel right. Check the CV boots on the rear.

Make sure all lights, horn, locks, radio, antenna, A/C and heating, rear defroster, windows, and guages work.

Look at tire wear. Brand new tires can be a visual mask for suspension problems.

Check brake and accelerator pedal wear.

Check for pulling on either side when test driving.

If possible have some one follow you while you test drive the car, so they can check for "crab walking" and can also tell you the color of the exhaust smoke, if any.

A hard shift can be due to lack of vacuum, or the modulator needs a bit if tweaking.

That's about all I can think of.

Jeremy5848 · #4 09-29-2006, 11:48 AM

Quote:

Originally Posted by psranga

4. The 300SD shifts hard from first to second during hard acceleration.
Is that a problem?

My 300D also shifts hard from first to second when the transmission is cold. Once I've driven for awhile and everything has warmed up, the hard shifting goes away. I read here some months ago that it's just the nature of the beast. That is something you can easily check yourself in 30 minutes. On the other hand, it could also be a vacuum problem, as others have said, but I think that would affect all of the shifts, not just 1-2.

Cateaux · #5 09-29-2006, 12:27 PM

Be sure that it's stone cold the first time you start it. Alot of sick engines run fine once warm, but have issues with cold starts.

Keep an eye on the oil pressure too. It should be pegged when cold, and should never drop below 1.5 bar at idle. You should always have at least 3 bar above 1K RPMs with the engine warm.

Check thoroughly for rust, too. lift up the spare tire and check underneath, as this is a common place for rust. While you're in there make sure the jack and tire iron are still there. Mine were MIA when I bought my 300D. Somehow I managed to check the spare tire well and spare without even noticing that the jack and tire iron were gone

. Luckily, I realized it before having a flat.

#6 09-29-2006, 01:58 PM

Main things to look for are as follows:

Make SURE that the car starts easily when cold. Don't worry so much about "blow-by."

As long as the motor quickly grumbles to life first thing in the morning you should be okay.

Transmission rebuild/replacement is very expensive.

Mine failed at just over 200K

(I now have 250K) but some last much longer than that. It is difficult for an amateur to tell if the transmission is bad or if the vacuum modulation just needs adjustment. The majority just need adjustment.

The A/C systems in these cars aren't very good. When still on R12 they are FREEZING cold

but many if not most have been sadly switched over to 134.

Air isn't as cold as it should be and compressors fail quickly.

A/C issues are expensive to fix.

RUST RUST RUST. This is the major enemy of these cars. Look everywhere. Behind and under the battery. Under the doors. Along the door sill. At all drain holes. Under the fenders. At the jack points.

If you find one that's not rusty, the air blows cold, starts easily when cold, and holds good oil pressure, then d#mn near anything else can be fixed with some effort and a little bit of $$.

Jim B. · #7 09-29-2006, 03:27 PM

In the CITY of San Francisco,

Sal's on San Jose Avenue would be a good bet, they know the older Benzes.

Pete's Inc. on Pacific Ave in SF is OK, but you will pay a high price, they are pretty good but not cheap

I would avoid every other shop in SF, I had bad luck, misdiagnosis, etc, especially avoid the dealer. I had a MB in SF from 96-04 and had much difficulty finding a good shop. There is not much to choose from there

Good luck the W123 and W126 diesels you are checking are both generally speaking, about the best in diesel choices you could make. You are on the right track. The early 300SD and the 77-85 300D/300D turbo are all excellent all around diesels. Avoid rust at all costs

#8 09-29-2006, 10:30 PM

Quote:

Originally Posted by psranga

Hello all,
1. Is there a checklist of what to look for when examining a used diesel
Mercedes?
Ranga

Answer: How do I explain the necessity of the purchase.

t walgamuth · #9 09-30-2006, 05:46 AM

Quote:

Originally Posted by ncof300d

Answer: How do I explain the necessity of the purchase.

to whom?

look for a nice smooth idle in a diesel. if it doesnt then it may have a weak cylinder. five cylinder will hop at idle but if you dont look at it it will sound nice and even. if it doesnt idle smoothly it still could be a good engine but if it does it probably is a very good sign.

tom w