He talked me out of it... - PeachParts Mercedes-Benz Forum

MercFan · #1 10-21-2009, 05:36 PM

Found a really shiny looking '87 300SDL: 262K miles, asking $3,500 - I spoke with the owner and he said that the car/engine is mostly original and needs few things: one of them was tie rod ends work (I suspect some other front ends parts as well), and a/c compressor hose. He said he was flexible on the price.

I called up a local shop to see if they would do a pre-purchase inspection on it, and spoke with the reputable mechanic (he has been recommended on this site) and we spoke for a while - and he talked me out of this car - saying that he's been seeing a lot of problems with 603 engines with 'those kinds of miles'... He said that if it had been a 5 cylinder (617) engine it would have been nothing, but not the 603... I took his word for it and cooled off about the car - but I'm wondering: thought the 603 engines pretty robust even with mid 200Ks on the clock?!

Renntag · #2 10-21-2009, 05:51 PM

Is there a list other engine designations, description, and models used?

603 and 617?

Is my 83 300TDT powered by a 603 ?

MercFan · #3 10-21-2009, 05:59 PM

Quote:

Originally Posted by Renntag

Is there a list other engine designations, description, and models used? 603 and 617? Is my 83 300TDT powered by a 603 ?

I think your 300DT is powered by a 617.952 (if I'm not mistaken)... I have a spreadsheet I copied from one of the links on this site - send me a PM with your email addrss and I'll send it to ya (did not let me attach it here).

James

blackestate · #4 10-21-2009, 08:45 PM

I was under the impression that the head on the early 603 was an issue, And if you got past that it was good. Do not remember the casting ID that you avoid..

rcounts · #5 10-21-2009, 08:52 PM

As I understand it, the 300D series all had OM617s until 86
86 and up (til 92?) had the OM603 with the aluminum head
IIRC the aluminum head casting you want to avoid is the 14 series - but I don't know how to tell one from another, never having owned or even considered looking for one.

NJ300sdl · #6 10-21-2009, 09:21 PM

Check for oil in the antifreeze and other signs of headgasket failure. Do not overheat the engine. Engine should run smooth with good power.

lvfast1 · #7 10-21-2009, 09:47 PM

My 87 300d has well over 300k on it with original #14 head and runs wonderfully. The car was abused by previous owners but i assume never overheated. I think the cracking head is a possibility in 86-87 300d's with om603 but definetly not the norm plenty of them still around running with original head its a crapshoot with that many miles if they let the car run hot as the radiator got old and plugged up or a slowly failing fan clutch (which is common)versus replacing promptly it could effect life of the head in my opinion. also I thought the om603 3.0 liter was only available in 86-87 the 87 and up got 5 cylinder om602 2.5 liter but i may be wrong..I love the w124 body and the power of the om603 so i may be bias toward going older for the slightly less chance of having a problem. By age alone the om617 are more likely to have a higher cost of ownership as the miles will be higher and the rest of the car is getting old and fragile I.E. interior and suspension. Just my opinion not based on owning the infamously bullet proof om617.

Arlo

Crazy_Nate · #8 10-21-2009, 09:57 PM

If there are no signs of overheating (cracked head, excessive coolant pressure, oil in water / coolant in oil), runs smoothly, has consistent and thorough maintenance records, I wouldn't be too scared of the engine.

Yes, the #14 casting is susceptible to trouble if overheated. If it's been well maintained (especially the cooling system), and the temperatures are watched, it won't be a problem. If you overheat it, all bets are off (or, rather, not in your favor)

My car runs nicely at 88-90C on the highway, and about 95-100C in warm weather stop-and-go traffic.

When I was considering the purchase of a '87 300D, I started a thread here. The chassis may be different, but all of the posts about the engine (OM603) are the same. Specific things mentioned are the condition of the head (and how to check for problems) and the vacuum pump, which may or may not be original on the car you're looking at. The general consensus is that the original vacuum pump should be replaced as preventative maintenance at these higher mileages.

Compared to the 616 and 617, the OM60x engines are quieter and more efficient (I've managed 30.7 mpg overall, with a high of 33.1 on one tank). The car is FAST compared to my 240D (

)

As always, YMMV, but, I'm thoroughly happy with my car, and plan on driving it for a long time.

MercFan · #9 10-21-2009, 10:52 PM

Quote:

Originally Posted by MercFan

...needs few things: one of them was tie rod ends work

How difficult is a tie-rod end job on these cars?! I've done the upper control arm replacement and front shocks replacement on my 300D - how would that compare in level of difficulty?! I suppose changing the tie rod ends also would necessitate the alignment... Other stuff?

Brian Carlton · #10 10-21-2009, 11:28 PM

A 603 can go 400K miles before it needs any serious work.

On the other hand, it can go 150K miles and need a complete overhaul.

It all depends on the maintenance given (specifically........oil changes).

The mechanic might have experience with engines that have not been carefully maintained.........but, that's no surprise.