just bought a 1987 300SDL for $500
 

was an old customer from the shop i used to work for, i was actually the last tech to do an oil service on it!lol
the car is in excellent shape interior is like new. it has 212000 miles. only issue i can see is it has possibly a blown cylinder head gasket and differential is noisy. cooling system builds about 15-20psi at idle. everything else is perfect, runs good, cruises nice. i will likely repair and keep it and sell the japan model 560SEL.

cylinder head issue?


don't fix the head- buy a new one.

at this point it is a head gasket issue, once i remove the head and i inspect it if there is something more involved it will be determined at that point if a new cylinder head is the correct repair.

You are are a great tech, this should be no problem for you...


If you market the 560SEL carefully you should be able to get a very decent price from it, paid by a discerning buyer that understands EXACTLY why those Japanese W126ers are so rare and desirable in this country


Diesels rule OK!!!!!!! :vbac47679

You'll have to be a lucky man, Ray, if the problem is just the gasket and not the head. Most who have pulled them find the bad news between the injector holes and one of the valves.

But, keep your fingers crossed..............

In my experience with the 603 engine, I map out cylinde rhead repairs with the following plans:

a. oil leakage from/around cylinder head, including poor oil pressure to one particular tappet> usually a head gasket

b. excessive cooling system pressure> I assume its a cracked head, and then if I am able to verfiy after removal that the head is ok, then I celebrate.

9 times out of 10, the heads are cracked.

the exceptions tend to be very late #20/23 heads- these seem very storng and wer eused on late 603.971 motors [S350]

Other than having the steering wheel on the wrong side, ... what's special about a Japanese 126??

i have not yet removed the head, but i am 99% sure it is cracked.
my casting number is 603-016-14-01 and from what i have read any head with #16 or lower is the vounerable head. i called mercedes today, and they can get me one for $1720.00 it is part number 603-010-96-20 list for that unit is $2140.00
so i believe i will prepare myself with a new head assy from mercedes and do it the right way.
everyone iknow is saying "get a used one" or i know a guy who can fix it" yea? for how long will it last!!
for the short time i have had this car and even shorted distance that i have driven, i feel it is worth the correct repair that will last.
besides i paid $500.00 for it., how can i complain about having to put a few $$ in it!!

is that the right part #?
I thought the 20 head had the 20 where you have the 96...
also, I thought the latest head was the #22 and it needed new PC's and a few other new parts...

Yes it is correct, there is a difference between casting part number and actual part number, the one with 22 is the casing, the one I posted is the part number. would appreciate any info on the needed pieces when purchasing a new head

You will need prechambers and nozzle holders/injectors, and if you're in there, seems an updated vacuum pump is in order. One of the guys here has a thread on using the old injector nozzles by doing some machining to make them fit, and I'm told that the original injector lines can be manipulated to fit the new angled injector position if you prefer that over buying new injector (fuel supply) lines.

You of course have considered cam, valves, and lifters, gaskets and a timing chain, what you're buying new and what you're carrying over from the old head.

BTW, if the head isn't cracked, ... and it might not be, your money but it seems like a gasket and drop it back on is the way to go. Otherwise, there is almost always someone looking for a 603 head somewhere, even as a spare.

if the head shows no cracks be sure to have it pressure tested and then have it resurfaced, just a skim cut at the minimum before reinstalling it. I've been down this road, I paid $475 for a nice 300D sans head in a mechanics lien sale.
I replaced the items listed previously (lifters, timing chain, etc.) as well as an updated vac pump (I was surprised the original hadn't failed as the car showed 224K miles on it!). I also opted for a new water pump and while I was in there I should have replaced the front crank seal that turned out to be something I had done later (I don't have access to a lift any longer).
You are a good mechanic, I can tell but check the radiator, be sure the car has a good one, if its the original I would replace it as a matter of course. The 603's need all the cooling they can get.

We know that many of the 603 heads cracked because of failure of the Nasty Trap Oxidizers but I have a theory that a lack of maintenance in the cooling system category is also a big factor, like the AC fan stops working and people keep driving and then hit a uphill on a hot day with the AC running and a crapped up radiator and that pushes it over the edge and the head cracks.

I installed a used #14 head and its been fine for about 2 years of intense driving fun in my second '87 300D (love em!) and my wife's daily driver is the other '87 300D with a #14 head also resurfaced and new lifters and a shotgunned cooling system. I figure they will still be running another 250K miles from now (if diesels are still allowed in the state of Calif!).

well i have figured my options, and here they are
1. buy new head from mercedes for $1,700.00 that will still require some parts and minor assembly and prechambers $110.00 ea) likely well over $2,500.00when done

2. get an assembled new MB unit from metric motors for $2,850.00 minus prechambers $110.00 ea) well over $3,000.00 when done

3. i found a good used 603-016-18-01 for about $650.00, donor car had 190k miles, no cracks in good shape. i figure i can get it rebuilt and be good to go for around $1,500.00

so within my $1,500.00 budget i will get the head and rebuild it and replace timing chain and vacuum pump and cover all other parts related to the cyl head replacement

To add to your glee, I don't believe that the #18 casting came on a car in the US, which would indicate it has less than the car's mileage on it (likely much less). What year is the donor?

that is good to know, i did not ask, but when i order it tomorrow i will find out.
more specifics on it.
i found a few here in san diego locally, all were #14 and were close to $1,000.00 :eek:

a guy even tried to sell me a complete engine it too was #14 lol