Wrong 3.5L head for my 3.0L OM603? - PeachParts Mercedes-Benz Forum

Vilnis · #1 02-28-2015, 07:23 AM

Hello everyone!

You all guys have helped a lot before, I have big dillema right now so I need Your opinion a lot.

I have OM603 3.0 turbo diesel with #14 head in w124 sedan(saloon).
The head is cracked and I got high cold pressure, which I did not see until I replaced the coolant reservoir.

My idea was to swap head from 3.5L engine as a lot of recommendations have been found here. Fortunately I found 2 heads in my country - Latvia (Europe). One of them was allready cleaned, machined and sealed, so chose that to have less problems with searching for a good shop to do that. Seller said that it was from w140 3.5L turbo diesel.

Casting number was R 603 016 10 01. I was not able to find any info about #10 head, but some said that sellers often mistake those numbers.
He sweared that it is from 3.5L turbo and it will definately fit my block and injectors. I was bit afraid but I bought it.

After short I found this info from forum(posted by babymog):

Engine ----- previous cast no. --- new cast no. --- Production Breakpoint
_______________________________________________________

602 ---------- 602 016 03 01 --- 602 016 07 01 --- 09/89

602 Turbo----- 602 016 06 01 --- 602 016 08 01 --- 07/89

603 ---------- 603 016 10 01 --- 603 016 16 01 --- 10/89

603 Turbo----- 603 016 15 01 --- 603 016 17 01 --- 07/89

Oh Murphy and your laws, why? So turns out that it is NA head? I called him and he again said that there is no differences at all, however some in forum said that they should not be used on turbo.
I can bring this head back and get my money.

But now I am in a great dilemma. Head is prepared and is in good condition. It is hard to find good head also in here.
But if the head should not be used I don't want any experimenttation and changing head once more.

There is also strange thing between #1 cylinder valves. Does not look like crack but bothers me too.

All of Your opinion and information about these heads and situation in overall would be invaluable.

Pictures of new head are attached to the post.

Thanks.

Vilnis · #2 02-28-2015, 07:26 AM

Also not sure about the injectors. As I mentioned, he said that mine should fit if I have the prechambers with those tooth inside.

I am not sure how inclined, non - inclined prechamber should look.

And those corrosion things all oround the head surface that goes to the block bothers me too. He said this is normal.
I actually don't know. Maybe this head was allready swapped from non turbo to turbo and those are made by channels that don't exist in the head but exist in the block?

sixto · #3 02-28-2015, 02:35 PM

I'm not familiar with options and varieties of heads outside the US. You have to wonder why MB would have a different casting number for naturally aspirated and turbo engines. Mind you, there is a different part number for the head on EPC which is the head with valve seats, valve guides and a few plugs. If the difference is in the added parts such as hardened valve seats, what could be different about the casting? Maybe it's just a processing and accounting convenience. Will a #10 head work on a turbo engine? I'm sure it will as long as you don't pull heavy loads uphill everyday.

I don't know about that mark between the #1 valves. Looks like a dent more than a crack. Cracks usually start in #4 and #5 so the head could be okay. Or the mark is remnant of a weld repair in which case I'd only use the head as a parking stop.

Those prechambers look to be the kind for inclined injectors. I hope you have a set since the vertical kind won't thread into those prechambers. You should be able to move your slotted lock ring prechambers and injectors to this head.

I don't know what you mean about corrosion. Do you mean that yellow stuff in the coolant passages? Ideally they would have been cleaned when the head was cleaned. Maybe you can use citric acid to clean as much as you can before installing he head. Rinse thoroughly!

Did you check if naturally aspirated and turbo head gaskets share a part number?

Sixto
MB-less

HappyHappy · #4 02-28-2015, 03:19 PM

Good pictures!

Those prechambers are for inclined injectors, the injector threads directly into the prechamber itself rather than into the prechamber ring as with the non-inclined injectors.

I' don't know for certain, but with the 602 series 5 cylinder engines there is a difference between the prechambers for turbo engines and non-turbo engines. Turbo engines use prechambers (both inclined and non-inclined)that have a larger diameter "nose" of the prechamber, the part that protrudes into the combustion chamber, I think turbo engines are 15 mm in diameter while NA engines use a smaller diameter nosed prechamber of 14 mm.

If that scheme is also used in the 603 6 cylinder engines the holes, the prechamber "nose" bores machined into the cylinder head are smaller for NA engines (14 mm) so the Turbo prechambers will not fit because they are larger diameter and need a 15 mm bore.

Just checked the Mercedes Engine manual for the 602 and 603 engines, the 603.912 is the 6 cylinder NA engine and it uses smaller "14 mm Combustion neck OD prechambers" on page 01.10 - 417/2

you should be able to measure the tip of that "nose" of the prechamber protruding out of the cylinder head and by that determine if your Turbo prechambers could be used.

There may be other differences such as Sodium filled exhaust vales or hardened valve seats but I haven't seen that detailed anywhere.

Cracks are often visible usually extending between the prechamber bore and the valve, as far as the ones I've seen.

Vilnis · #5 03-01-2015, 04:58 AM

Thank You sixto and HappyHappy for involvement!

By corrosion I mean these things that I have on pictures. My head did not have anything like that. Master said that it is sign that head had been used with water instead of antifreeze for long period.

Friend that works in part shop said that gasket and vavles should be the same.

One master said that valves with non-turbo camshaft are opened further.
He said that it is some kind of dent but people do so to mask the cracks.

Vilnis · #6 03-01-2015, 05:02 AM

Also I have found that I have #15 head not #14. Somehow I missed that.
These seem to be inclined injectors as I undestand?
So these injectors will fit any #17, #17, #18, #20, #22 head?

mytmousemalibu · #7 03-01-2015, 05:52 AM

Also, since this head has been milled flat, the deck has of course been thinned a bit. You might need to put in different thickness prechamber seal shims to adjust the prechamber protrusion from the head. You don't want your pistons contacting them!

To me, personally, that corrosion looks pretty nasty, I would be concerned with the integrity of the cooling passages, hence chances for cracks to possibly form. Can you take some closer photos of the line/dent/scratch of cyl #1 with it clean and dry? I would investigate that very closely. Some of the aluminum near the exhaust seat has been peened over, makes me wonder why. Need to be like Sherlock Holmes with this stuff, be very cautious, careful and diligent.

Vilnis · #8 03-01-2015, 08:04 AM

Here are the pictures:
http://1drv.ms/1EXPUTi
http://1drv.ms/1BOekBw

something interesting for other cylinder:
http://1drv.ms/1EXPYCt

Interesting that something was done to prechamber sockets, is it machining to change type? :
http://1drv.ms/1EXQ3WF

Prechembers must have got problem with taking them out:
http://1drv.ms/1EXQgJE

Vilnis · #9 03-01-2015, 08:10 AM

mytmousemalibu, thanks for the information. This bothers me too much. The more I look on this head and more I hear from people, more I think about giving this head back.

It seems that even welding of my head is better idea than put this on.
One master told me to search for head that hasn't been touched, is dirty and oily.

vstech · #10 03-01-2015, 08:25 AM

The "dent" between the valves is from a welding of the cracked head previously. It looks to me like a shoddy job too...

Shortsguy1 · #11 03-01-2015, 09:12 AM

If the price of that head was very low, then perhaps keep it. But if it was expensive, you need to ask for your money back. The list of things wrong with it are way too long:

NA head
severe corrosion
cracked (and perhaps repaired)
??

mytmousemalibu · #12 03-01-2015, 02:25 PM

Yeah, personally, I would have to pass on this one. Too many issues and I'd hate to see you install this one and have problems. Sucks having to hunt down another good head but if its worth your time to replace it, its worth your time to find a better condition head from a proper 603 turbo.

Vilnis · #13 03-01-2015, 05:16 PM

I am taking this head back to seller this week. Thanks for the opinion and suggestions.

Does anybody has some experience or have some info about welding these heads?
Should I consider this if I can't find any good head?
I have heard of some shop in neighbor country (Lithuania) that offers welding with 1 year warranty. Guy that told me that said that half of the people that work with heads in my town sends heads there for welding and surfacing.

HappyHappy · #14 03-01-2015, 06:57 PM

Here is someone on this forum posting a #20 head in Europe, looks like Poland maybe.

http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/366121-fs-om603-20-cyl-head.html

sixto · #15 03-01-2015, 08:02 PM

Quote:

Originally Posted by Vilnis

Also I have found that I have #15 head not #14. Somehow I missed that.
These seem to be inclined injectors as I undestand?
So these injectors will fit any #17, #17, #18, #20, #22 head?

Inclined injection is native to #17 and later castings at least for turbo engines. Vertical prechambers can be adapted to #17 and later castings so you can use vertical injectors but either the prechambers or prechamber pockets have to be machined. In your case, inclined prechambers appear fitted to an older head. That's either a non-US configuration or a mechanic used whatever parts were available.

1 year warranty = do you really want to do this again next year?

Sixto
MB-less