I have two 124's, one with replaced head, one with original. The one with repalced head has 318K on it now, head replaced at 270K, trap done shortly before that. Other car has original #14 head, no trap, currently 218K mi.

Head cracked 248k.Replaced whole engine, has 110k on it.Head no.p603 016 1501.

I still got the #14 head and 500,000 miles. But I bought the car with an open title from a used car dealer...car fax research and the name on the title confirm it was a one owner car, and well cared for it appears.

I should get one vote for each 603 I own.

'87 300D with 317000 and a "14" head, don't know if it's original or what. I was very concerned as there was oil in the coolant tank. Flushed the entire cooling system and found no oil in it. Refilled with Zerex and have been watching it. Coolant level seems to be good with no residual pressure after sitting overnight. I will need to change the fan and clutch as the fan spins for a while after shuting the engine off. I will be pulling the intake off shortly to do a cleaning (egr was still hooked up), compression check and check for oil leakage into #1 cylinder. Also plan on pulling the valve cover to check things in there as well.

What about people with rugged 617's that don't have such weaknesses? :D ;)

It's the price we pay for quiet and horsepower.

Eh, my 300SD can go fast enough to send me to jail.....so I don't need much more HP in my daily driver. I have my 300E to go fast. Quiet is overrated, I love the sound of the 617....way more truckish and rugged than a 603. I drive mine 80 miles a day and love every minute of it. :D

In any 603 thread there will eventually be a "don't you wish you had a cast-iron head" type posting.

The short answer is no, and I don't wish I had a Model A for its simplicity either, ... some of us are very happy with technological advances and refinements, give it a rest.

Amen to that. I've owned both and there's no way I'd go back to a 617 engine. The 60x is a full 20% more efficient both in power delivery and fuel consumption, is significantly quieter, requires less routine maintenance, and has a number of user-friendly improvements like a built-in turnbuckle for IP adjustments, turbo oil drains that keep oil inside instead of outside, auto-tension serpentine belt, and IP's that can be adjusted via "dry" methods instead just to name a few.

The 617's main claim to fame is that it is nearly indesctructible, but the list of annoyances and flaws is extensive. The OM603 is the opposite... long list of improvements / advancements, with the single flaw that the heads used in the first 2 years of production (out of about 10 years total) were a weak design and can crack when overheated. Replace the head, and that one flaw is eliminated.

The folks who are pro-61x and anti-60x are almost always the ones who have not owned a good-running 60x engine, and/or haven't worked on them enough to understand them as well as the 61x which they know very well. That's their loss, though... *shrug*


:chinese2:

Late response to poll
 

Trap removed at 49K
-14 head cracked at 67k
Entire engine replaced at 178k
-22 head cracked at 201K (Replaced under new engine warranty)
Now at 249K and running fine.

My sig is out of date

Seriously? Did you see the cracked #22 head? I don't think I've ever heard of one cracking before. Where were the cracks located... between the valves, or valve to prechamber? What led up to the cracking?

:nuke:

The head gasket on my OM603 is leaking oil around one of the head bolts and the engine still runs hotter than I like it to, but the #14 head hasn't cracked yet. The engine doesn't loose any coolant, and there is no oil or water intermingling. It doesn't show any hard hose symptoms when cold either. Hopefully, I'll get to the citric acid flush this summer, but there is a laundry list of other stuff to take care of since I have had my 1987 300TDT for 6 years now.

I have been looking for a replacement head for a while, and I always seem to miss them at the wrecking yard. It's kind of funny I came across a 1987 300D in the South Sacramento PNP that I had looked at in 2004 when first started searching for a W124 with an OM603. In 2004 the seller told me it had a new head because the original #14 cracked. Sure enough the "new" head was gone from the engine when I saw it. Last time I went to the Moss Landing PNP in January there was a 1987 300D with cracked #14 head in the yard.


I still would take a OM603 any day over the OM617. My Mom used to own a 1981 300D that I learned to drive on (and I had to take care of). The OM617 was naturally aspirated and quite reliable, but the power difference and refinement was like night and day. Just my two cents worth in a long running debate.

If the oil leak is directly below the timing chain tensioner, coming from the head gasket itself... you can try tightening the two head bolts at that corner of the head slightly. The main pressurized oil galley is in that spot, between two head bolts. I tried this on my project car, and it worked surprisingly well. I loosened the two bolts slightly (approx 20-30°, or 1/16 turn), and then tightened them approx 45° (1/8 turn) past the original position. This was enough to stop the external oil leak. Just be warned that if anything bad were to happen (broken bolt, etc) the worst case is that you might have to pull the head to repair it. I've done this twice now with good results, it's worth a try if that is the only slight leak.

If the oil leak is in a different location, the above info doesn't apply.


:1eye:

The oil is coming from around the second or third head bolt on the driver side I believe, but I will have to examine it more closely. Thanks for the tip GSXR.

BTW, do you know of a good source for the special socket required for the head bolt?