Check out the thread below from a MB Technicians forum. In short, not all M119 block are interchangeable, specifically a M119.970 vs. M119.972 blocks.

I would hypothesize that our 500E blocks (all M119.974) are also not interchangeable, so caveat emptor.

:-) neil
1988 360TE AMG
1993 500E


============
Well, I will tell you everything works fine [the swap] would I ever do this again? NO. The
timing cover is different on the 972 engine (vs.970) and does not have the front speed sensor, oil pan and the sub-pan had to be swaped, the EA was different; had to be swaped along with all
pulleys have a different amount of grooves the belt tensioners different; the PS pump along with the bracket different; the AC compressor along with the bracket different; all of which had to come off regardless for the timing cover the engine hangers are different where the bolts go through the 972 engine takes a 10 mm bolt where the 970 engine takes an 8 mm bolt had to drill the hangers from the 970 engine so the 10mm bolts would go through the manifolds are different. I guess if you had a long block it may not be that bad but when you have 2 complete motors it is a lot of work like I said will not do this again for anybody they will just have to buy for same model.

From the sound of it it's not the blocks that are different, only the ancillaries. Sounds like the engine change worked fine, just that it was a lot of work swapping all the external components.

__________________
Glen Tokuhara
Beauty & the Beast and the wagon that could!

Glen- I agree, mostly "ancilliary" equipment, but who knows for sure. I still would try to source an actual M119.974 block for our 500E's, especially with the different engine mount holes for the W124 application.

Here's a post I did a while back:
----------------------------
In addition to the different cams, intake manifold, LH injection, and the crankcase holes for the engine mounts, here
are more differences on the 400E/500E engine (there's a LOT more), taken from the MB's Introduction to Service:

1) Oil pan: upper and lower pan havles modified to accommodate front crossmember. Upper: cast aluminum; Lower:
steel. Oil pan gasket and baffles/windage tray modified;

2) Belt Length modified (2465 mm);

3) Modified EGR & Air injection;

4) Oil pump strainer and oil level switch modified due to different oil pan;

5) 1-pole oil pressure sensor on steel oil line identical to non-M119 W124's;

6) Oil dipstick tube modified due to oil pan;

7) Oil cooler line connections are sealed-off with a plug & O-ring since an engine oil-cooler is NOT installed. Oil
thermostat was also deleted.

8) Viscous fan clutch housing modified to bring fan 8mm closer to engine;

9) Viscous fan engagement was lowered from 96-C to 82-C;

10) Heater return fitting modified to available space [in W124 chassis] on the right rear of crankcase;

Hope that helps,
:-) neil
1988 360TE AMG
1993 500E

Dean's Need2Speed site has an article that was published in the April 2002 issue of Mercedes Enthusiast magazine which says that the deck height and various internals of the M119.974 engine were altered so that everything would fit under the hood.

http://www.homestead.com/need2speed/testbed.html

Jim

__________________
--
Jim Stadter
'94 E500 Black Pearl
'89 190E 2.6 Black Pearl
'88 928S4 5-speed
Austin, TX

hi all,
I have a 92 400e with a damaged engine (metal shavings in the oil), recently I found a 5.0 m119 off a 93 SL500, from what I read so far there seems to be some differences between the two, but if we assume that I use all the accessories from the 4.2 (alternator, powersteering pumb, A/C compressor) and oil pan and attach them to the 5.0 won't it be a straight forward swap?

Or

How about taking the crankshaft+rods+ pistons from the 5.0 and into the 4.2 (since I belive the damage is to the crankshaft and bearings), or will I run into deck height and compression problems?

So far I found these two threads relating to the same topic. If anyone has more please post them M119 CHANGE 4.2 to 5.0
5.0 litre motor into a 400e, can it work?

I think this is a good question. I've wondered about the feasibility of buying an E420 and swapping in the 5.0 engine. Could be a poor man's E500.

__________________
Brian Rogers
'96 E320 traded in at 292,000 miles
'09 C350

My 97 E420 still looks good and drives great, but I would consider that if the engine gave out.

__________________
With best regards

Al

You will need the EZL and ECU, otherwise, I think it's a simple swap.

:-) neil

Won't the 5.0 work with my existing EZL & ECU? I realize the map might be different for the two engines, but I was thinking about compensating for that by tuning the fuel regulator.

are the W124 and R129 ECU's the same?

Bump.