New to Benz. 89' 300d questions.
 

I am looking at a 1989 300d turbo to convert to WVO. The car has been sitting on the back lot of a freind of mine for about one year. Interior good, paint and body good. Engine.......blown head gasket, as told by a former mechanic of his. 186000 miles. I can get it for $300 bucks. I have an F350 7.3 and have learned some about diesels and bolt ons. Rebuilt gassers , but never inside of a diesel.
1) What would cause the head gasket to give?
2) How much of a pain to replace?
3) What else to change while I am in there......timing belt, ect.?
4) Aluminum head........should I have that checked too?
5) Also, the head lights are fogged over from water inside the light.
6) Before I do anything I will put a battery on her to make sure it has not locked up. Hope there is no water in the cylinders.

No such thing as a 1989 300D. Find out the year, without the year we don't know what kind of engine it has.

Sounds like it might be a parts car though, from not even seeing it I bet it takes a few grand to get road worthy.

Is this a non-US car? The 300D was sold in the US from 75(?)-87 but not in 86, then again from 90-93. Can you provide the first few characters of the VIN (WDBEB3x or 1241xx)?

1) If it has a 603.96x engine then a cracked head is not uncommon. Similar symptoms to a blown head gasket. Overheating will make a paperweight out of the cylinder head in short order.

2) I weigh ~150 lb; can't bench my weight. I replaced a head 603 head pretty much by myself. I needed a second pair of hands to position the head over the block.

3) Quite possibly the head itself :) It's a little easier to get to the water pump with the head off. Glow plugs. Turbo seals. Valve lash adjusters if their noisy though you won't know if the engine isn't running now. I think you can test them but I wouldn't trust a test on an engine that's not been running for a year. You're that much further into pulling the front cover to replace the tensioner rail and oil pump drive chain but that's a heck of a lot of work.

4) Most definitely!

5) If the car has US DOT spec headlights, lift the front wheels, put a headlight assembly under each wheel, release the jack. Repeat until the headlights are in a million pieces. Then get a set of E-code/Euro headlights which actually illuminate what you need to see to drive safely at night. IF they are E-code headlights, it's possible to remove the lens from the reflector. Clean as best you can. Be very gentle with the mirror as the slightest wiping will destroy the reflective finish.

6) How about taking a 27mm socket to the crank pulley to accomplish the same thing? Remove the injectors (takes a 27mm deep socket) to make it easier to turn the engine.

Sixto


Sixto

Oh, don't turn the engine in reverse rotation!!!

Sixto

I will have to check with him about the year, it was kind of in the weeds and I only looked inside and did not open the doors. The truck lid did show "300d" on the left and "turbo" on the right.
Sooooo......it should turn counter clockwise, right?
Also, where would be the best place to buy the new head? Dealer or is there an after market that may be better for the next 200k miles?

Turn the crankshaft clockwise only.

If you can find a nice used head, that seems to be the way to go. Try Craig's List (see CL watch thread at top of forum) or eBay or your local newspaper. The best way is often to find someone parting out a car and get the head off of that.

If I remember correctly you will want to look for a number 17 (I have a 14 which is not good), on the driver side of the head there is a line of numbers cast into it. The number you are looking for is the last two digits. Apparently the later model heads were not as prone to cracking.

I have seen these for $600 - $1000.

I have seen these for $600 - $1000.

Ouch! What would be a later year?

Very likely an 87 then.

The head part number as cast near the #2 injector is R 603 016 XX 01 where XX describes the replacement sequence. Original heads will have a -14-, the 3.5l engines originally cam with a -17-, the latest revision is -22-. The heads are interchangeable but moving from a -14- to anything newer requires some simple modifications. It's all in the archives.

Sixto