Need primer on various OM603 heads: - PeachParts Mercedes-Benz Forum

treetrimmer · #1 03-27-2012, 09:37 PM

I just did a quick search and could not find my answer. How many different heads did MB put on the OM603 engine? I'm familiar with the #14, (was that the first one?), and of course the final #22.

What I'm wondering is how many were in between and the actual difference between them, if anyone knows. Also, approximate dates of production for the various castings. The first ones must have been in 1986 and the last ones came on 3.5 engines(?)

Thanks a lot.

Bio300TDTdriver · #2 03-28-2012, 10:28 AM

Quote:

Originally Posted by treetrimmer

I just did a quick search and could not find my answer. How many different heads did MB put on the OM603 engine? I'm familiar with the #14, (was that the first one?), and of course the final #22.

What I'm wondering is how many were in between and the actual difference between them, if anyone knows. Also, approximate dates of production for the various castings. The first ones must have been in 1986 and the last ones came on 3.5 engines(?)

Thanks a lot.

See post #25 in this thread. Also so this thread.

treetrimmer · #3 03-28-2012, 12:44 PM

Thanks a lot! That still does not list all of the various OM603 heads and dates, though, plus the changes to each. Anyone else?

Bio300TDTdriver · #4 03-28-2012, 01:16 PM

Quote:

Originally Posted by treetrimmer

Thanks a lot! That still does not list all of the various OM603 heads and dates, though, plus the changes to each. Anyone else?

Did you try the search feature?

treetrimmer · #5 03-28-2012, 05:37 PM

Yes, I did. Came up dry, so I'm asking here. Do you have any info, or just chiming in?

Bio300TDTdriver · #6 03-28-2012, 07:33 PM

Quote:

Originally Posted by treetrimmer

Yes, I did. Came up dry, so I'm asking here. Do you have any info, or just chiming in?

I spent 30 seconds searching and posted 2 links. The ifno is out there, but it may require some effort on your part.

treetrimmer · #7 03-29-2012, 01:24 PM

I appreciate the links but they still don't answer my questions. Nor did a search. I always try the search feature first. Anyone else?

Jeremy5848 · #8 03-29-2012, 02:38 PM

Quote:

Originally Posted by treetrimmer

I appreciate the links but they still don't answer my questions. Nor did a search. I always try the search feature first. Anyone else?

As you have discovered, this is not a simple question. The subject has a number of major divisions:

1. a) OE heads on 603.96 engines delivered in the USA (300D Turbo)
b) OE heads on 603.97 engines delivered in the USA (300SD/SDL)

2. Replacement heads sold by MBUSA to those repairing the above vehicles.

3. Turbodiesel heads on vehicles not sold in the USA.

4. Heads on normally aspirated 603 diesels not sold in the USA.

5. Gray market versions of #3 and #4 imported into the USA.

I personally know of five heads suitable for use on turbodiesels: #14 (the original), #15, #17, #20, and #22 (the last). There may be others. Sixto is of the opinion that #20 and #22 heads were never delivered on an engine in a new car; he thinks that they were available as replacements only.

Production breakpoint data is rarely available. Babymog's note in the thread referenced above is one of the few I've seen. My paper FSM also gives the information he lists, suggesting that the #14 head was replaced by #15 and then #17. (It is thought that the #16 head was for NA engines.)

Also note that the head casting number is in the form "603 016 xx 01" where xx is the head version number. Many of us have made the mistake of thinking that the "016" was the head version number; it is not. Also note the warning in the FSM: "Caution! Do not mix up cylinder heads for turbo-engines and naturally aspirated engines." In the USA this is not a serious problem because so few NA engines have been imported. Beware, however, of NA heads listed on eBay or some other such place.

The paper FSM section 01-400 "Repair Notes for cylinder heads and cylinder head gaskets" lists many changes, as Babymog has shown, and gives production change dates. However, head casting numbers are not given except in one case (which Babymog quotes) and the changes are usually given based on engine numbers.

I know this isn't all you wanted; maybe you will have to take on the job of assembling the master document of 603 head information for all of us.

Jeremy

Bio300TDTdriver · #9 03-29-2012, 04:01 PM

Quote:

Originally Posted by Jeremy5848

I know this isn't all you wanted; maybe you will have to take on the job of assembling the master document of 603 head information for all of us.

Jeremy

Or brush up on your German and locate and interview some of the engineers that worked on the heads for MB.

Please keep us updated with your research.

atomix8 · #10 03-29-2012, 05:41 PM

Never thought about it...anyone know the differences between the non-turbo and turbo heads?

I've always assumed the non-turbo heads just aren't built for the extra heat & stress "somehow," but never thought that they wouldn't interchange.

*eyes original #10 head & headgasket...*

Jeremy5848 · #11 03-29-2012, 06:06 PM

Quote:

Originally Posted by atomix8

Never thought about it...anyone know the differences between the non-turbo and turbo heads?

I've always assumed the non-turbo heads just aren't built for the extra heat & stress "somehow," but never thought that they wouldn't interchange.

*eyes original #10 head & headgasket...*

Mechanically, they probably will interchange, but the NA head may lack some coolant and oil passages that the Turbo head has. It would be interesting to see photos or diagrams of both kinds. Maybe our friends in other lands where the NA 603 engine was sold can help us.

Jeremy

Hit Man X · #12 03-29-2012, 07:00 PM

Quote:

Originally Posted by Jeremy5848

As you have discovered, this is not a simple question. The subject has a number of major divisions:

1. a) OE heads on 603.96 engines delivered in the USA (300D Turbo)
b) OE heads on 603.97 engines delivered in the USA (300SD/SDL)

2. Replacement heads sold by MBUSA to those repairing the above vehicles.

3. Turbodiesel heads on vehicles not sold in the USA.

4. Heads on normally aspirated 603 diesels not sold in the USA.

5. Gray market versions of #3 and #4 imported into the USA.

I personally know of five heads suitable for use on turbodiesels: #14 (the original), #15, #17, #20, and #22 (the last). There may be others. Sixto is of the opinion that #20 and #22 heads were never delivered on an engine in a new car; he thinks that they were available as replacements only.

Production breakpoint data is rarely available. Babymog's note in the thread referenced above is one of the few I've seen. My paper FSM also gives the information he lists, suggesting that the #14 head was replaced by #15 and then #17. (It is thought that the #16 head was for NA engines.)

Also note that the head casting number is in the form "603 016 xx 01" where xx is the head version number. Many of us have made the mistake of thinking that the "016" was the head version number; it is not. Also note the warning in the FSM: "Caution! Do not mix up cylinder heads for turbo-engines and naturally aspirated engines." In the USA this is not a serious problem because so few NA engines have been imported. Beware, however, of NA heads listed on eBay or some other such place.

The paper FSM section 01-400 "Repair Notes for cylinder heads and cylinder head gaskets" lists many changes, as Babymog has shown, and gives production change dates. However, head casting numbers are not given except in one case (which Babymog quotes) and the changes are usually given based on engine numbers.

I know this isn't all you wanted; maybe you will have to take on the job of assembling the master document of 603 head information for all of us.

Jeremy

I pulled a No 18 off a 3L SDL. No telling if it was from another car or what.

treetrimmer · #13 03-29-2012, 09:17 PM

Thanks a lot. I have a 1987 300SDL with a #22 head. I've only had the car for about a year so I have no idea how it wound up on the car. If I wasn't so lazy, I'd call a colleague who works at the dealer and see if an OASIS search on my VIN brings up any records, such as head and/or engine replacement during the trap oxidisor campaign.

I also have a spare engine pulled from a wrecked '86 SDL that has the #22 head. Same thing--no idea what the story is or how it got there.

Is there a certain delineation point where the heads got a lot better? I have always heard that the #22 is the best/last but was the #17 almost as good? IOW, was there one big improvement and then just further refinement? Thanks a lot. This is a great board.

Jeremy5848 · #14 03-29-2012, 10:40 PM

Quote:

Originally Posted by Hit Man X

I pulled a No 18 off a 3L SDL. No telling if it was from another car or what.

I have heard of that one but have never seen one. What did you do with it?

Jeremy5848 · #15 03-29-2012, 10:45 PM

Quote:

Originally Posted by treetrimmer

Thanks a lot. I have a 1987 300SDL with a #22 head. I've only had the car for about a year so I have no idea how it wound up on the car. If I wasn't so lazy, I'd call a colleague who works at the dealer and see if an OASIS search on my VIN brings up any records, such as head and/or engine replacement during the trap oxidisor campaign.

I also have a spare engine pulled from a wrecked '86 SDL that has the #22 head. Same thing--no idea what the story is or how it got there.

Is there a certain delineation point where the heads got a lot better? I have always heard that the #22 is the best/last but was the #17 almost as good? IOW, was there one big improvement and then just further refinement? Thanks a lot. This is a great board.

You are fortunate to have gotten two #22 heads.

I think most of us who sit around the fire discussing OM603 heads (we have no lives

) would agree that the worst of the problems were fixed by the #17 head and that the later revisions were "tweaks" by comparison. The pilot error problem (trying to "make it home" with an overheating engine) still exists; no head revision will fix that.

Jeremy