Mercedes OM603 FJ80

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May 21, 2011
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Anyone swap an OM603 into a toyota?

I have a good running 3L OM603 with newer head casting.
 
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If it is the same bell housing as the OM617 it would work with the kit from 4X4 Labs. I had a Mercedes G350DT with that engine and it got around fine, mine had the intercooler and put out around 165 HP, plenty for the Land Cruiser. The Mercedes is about the same weight as the Land Cruiser so it should work. One good thing about the Mercedes diesels is the engine likes to rev like a gas engine.
The only problem with that engine is that the fuel economy isn't very good, I was getting about 15 mpg on the highway, not much, if any better than the gas engine. The only reason to use this engine is to run biodiesel or WVO.
Where are you located? I am building an FJ40 and plan to use a Mercedes engine, would be interested in yours if you would like to sell? I want the Mercedes engine for WVO.
Good luck
Rusty
 
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I am in CA, the OM603 has a completely different bell housing than the OM617. Ive had a 300SDL OM603 (@5600lbs), a 190D OM601 (@2700 lbs) and a 300SD OM 617 (@5200 lbs). The 350 got the best mileage, would get about 25 on the freeway on long trips around 65-70 and could avg around 21-22 combined.

I can have an alum adapter made at close to cost, so bolting it in is not really a concern.

I am very surprised that your G wagon only got 15 on the highway, sure the cruiser or g wagon would be aero limited, but I would think it should be higher, I have friends with big diesel trucks that get better mileage than that.

IMO best mileage would be had with a more modern diesel such as sprinter motor.
 
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I was really surprised by the mileage of the G350DT, it did run at high rpm's on the highway, around 3,000. I spoke to several authorities on the G-wagens and they all told me that was normal but I can't help but wonder if that wasn't the problem with fuel economy. The G-Wagen is even less aero than a Land Cruiser so the Land Cruiser could do a bit better and have to believe if you could get the rpm's down to about 2,500 the mileage would go up.
Guess I will stick with the OM617 or possibly go the GM 6.2 diesel route again in my FJ40. I put a 6.2 in a 94 FZJ80 and could get about 20 mpg with that so you would think a 3.5L 6 cylinder would do better.
Good luck with your project, I think the engine could be fine in an 80 series if you don't plan on any towing or anything.
Keep us posted
Rusty
 
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A stock OM603 would make a fine motor for towing with a few mods, infact it would have more power and torque than the 3FE in my 91 even unmodified. They can actually make over 400 HP on an unmodified stock long block.

Hell The 1.9 and 2.0 VW TDI motors can make 175-220 WHP with 270-350 WTQ on stock blocks with most the power band in the 2-3k range.

I have an old Jetta TDI, DD that will spin the tires in third gear, its got a different turbo, tuned fuel injection and different injectors.
 
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???

benz bought chrysler, not the other way 'round. and they promptly sold it, now it has fiat as a partner. but some of the best benz units were built before 1992.
 
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To keep this thread going, the OM603 engine is @ 26in tall (at deepest portion of sump, front 1/3) 19 inches tall rear 2/3's, @32in long (rear flange too front of crank pulley, with an 11.5in diam flywheel.

I measured the weight at @535 pounds complete long block..

The engine I have is out of a 1987 E300, it makes around 150hp and 200 lbs torque stock, but can make in excess of 400 whp on a stock block.

As far as I know the 603 was only imported into the US in 85-87 (as a 3.0l) and 90-91(3.5l), these engines are externally impossible to tell apart without looking up serial numbers for parts which would otherwise be interchangeable (block, heads fuel injection pump, everything but pistons and crank). This is actually the reason I sought out a 91 FJ80, so that it could be smog legal (and smog exempt) in CA.






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benz bought chrysler, not the other way 'round. and they promptly sold it, now it has fiat as a partner. but some of the best benz units were built before 1992.

I was thinking the same thing.
 
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stay away from the 3.5 litre. i have a '91 350SDL that blowed up the engine, and it was replaced with the 3.0 om603 from a 1987 model. pretty much the exact same engine, except the 3.5 was bored bigger for the extra displacement. as it turns out, this made the walls between the cylinders too thin which resulted in warping of the cylinder walls and the eventual catastrophic death of the engine. the 3.5 litre is known as the "rodbender" engine.

the other pitfall of these engines was the trap oxidizer. originally these were placed in such a way that when (not if) they failed it sent particulate into the turbocharger which results in catastrophic failure. benz had a factory fix for these by putting the trap oxidizer downstream of the turbo. best bet is to remove it entirely. otherwise, the om617 and om603 are nearly legendary in longevity and performance.
 
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yes, although some 3.5's have gone the distance also. If the engine was replaced under warranty then they are supposedly bullet proof.

If not probably not a good used engine purchase unless just buying for the head which is an improvement over the original 3.0.

stay away from the 3.5 litre. i have a '91 350SDL that blowed up the engine, and it was replaced with the 3.0 om603 from a 1987 model. pretty much the exact same engine, except the 3.5 was bored bigger for the extra displacement. as it turns out, this made the walls between the cylinders too thin which resulted in warping of the cylinder walls and the eventual catastrophic death of the engine. the 3.5 litre is known as the "rodbender" engine.

the other pitfall of these engines was the trap oxidizer. originally these were placed in such a way that when (not if) they failed it sent particulate into the turbocharger which results in catastrophic failure. benz had a factory fix for these by putting the trap oxidizer downstream of the turbo. best bet is to remove it entirely. otherwise, the om617 and om603 are nearly legendary in longevity and performance.
 
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yes, although some 3.5's have gone the distance also. If the engine was replaced under warranty then they are supposedly bullet proof.

If not probably not a good used engine purchase unless just buying for the head which is an improvement over the original 3.0.

yes, the factory replacement units are a great engine. good luck finding one, they are as hen's teeth. the extra 0.5 litre gives you a bit more low-end torque, but i've been told that the actual "rubber-hits-the-road" difference between that and the 3.0 litre is pretty minimal. the 350SDL will still squawk the tires in second gear and haul-ass up 6% grade @ 70+ mph without breaking a sweat (the SDL is not a small car, and likely every bit as massive as an 80 series), in spite of being short 500cc.

if i had to do it again, i would have replaced the anemic 1L diesel in the hilux with a 190D 2.5 litre turbo, or an OM617 than a 3L with a turbo. much cheaper and easier to get parts for a benz diesel than toyota.
 
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I have a line on a cheap OM617 and approval from the wife to do an engine swap. Will the OM617 push my 93 cruiser when mated to a NV4500? What do you guys think?
 
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Austin Cruiser, I have driven an OM617 and owned an OM603 G350DT, the OM617 would be minimal I would think without some modifications, check the super turbo diesel website (I think that is it) They are capable of some pretty impressive numbers as is the OM603 but at what price?
The OM603 moved my G350DT comparable to my old FJ62 which I think is fine, but it also had a pretty rare intercooler and put out 165 hp.
Only problem with that engine is as stated above my mileage was only about 15 mpg, not worth the effort of a conversion. For the money I would still say consider a GM 6.2 diesel, I did a swap in a 94 FZJ80 and loved it, great engine for the 80 series and the mileage was around 20 mpg, torque was better than the OM603 too, best part is the price of the engine, parts and availability.
The OM603 was called a rodbender because of the increased stroke which was too much and eventually bent the rods which ovalized the cylinders. These rarely ended in catastrophic failure just premature lifespan for a Mercedes, that is why I was not worried about my G350DT despite all the horror stories.
You will hear similar stories about the GM 6.2, do some research, you will find it is actually a good reliable engine.
Good luck, I would be interested in the OM617 for my FJ40 project if you are not, I will send you a PM
Rusty
 
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rtarh2o: PM replied to. I am afraid of GM engines (except their Isuzu engines). I think that the OM617 would be OK in my 80, no speed demon, but OK. I am interested in joining the local WVO coop, so the Merc engine is a good candidate. My other candidate is a 3.9 Isuzu. It is more expensive, but a hell of an engine and will be a very good engine for the cruiser. The adapter to a GM tranny is cheap too.
 
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I am thinking of doing this swap also... currently 4x4labs has kits out for all GM stick shifts and the W56 yota transmission.

I keep going back and forward on this one :rolleyes:
 
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Considering the 617 or the 603?

2 different bell housings

I would guess that the 603 should best the fuel economy of a 6.2/6.5 gm motor if the gearing is right, from the research I have done the 603/606 should be just about the most advanced IDI diesel available.



I am thinking of doing this swap also... currently 4x4labs has kits out for all GM stick shifts and the W56 yota transmission.

I keep going back and forward on this one :rolleyes:
 
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I think i mentioned fuel economy in a previous post but will say it again.
I swapped a 6.2 GM diesel in a 94 FZJ80 with a 700R4 and 33" tires, I was running about 2,000 rpm at 65-70 mph, this is about 200 rpm out of this engines sweet spot for economy but I was still getting around 20 mpg and was running a WVO blend so maximum economy wasn't that important to me.
About a year after building the 6.2 80 I found what I thought was my dream vehicle, a Mercedes G350DT, the OM603 engine with a factory intercooler putting out around 165 hp. Powerwise was fine in the G Wagen, very similar to a 3FE powered 80 but the mileage was never any better than 15 mpg! The previous owner swore to me it got around 25 mpg which I knew going in was probably off by a bit but I really expected more than 15! I always suspected the gearing, it was running around 3,000 rpm at around 70 mph but it was a factory engine, not a swap so I assumed that is the way it was designed to be. I even tried some trips at 60 mph for a full tank of gas, dropping the rpm down to around 2,500 rpm and still the same 15 mpg?
Anyway, I did like the engine, great if WVO is what you want to do, the engine was very quiet at idle, especially compared to the 6.2 diesel but on the highway, they were about the same, the OM603 turning 3,000 rpm was possibly noisier than the 6.2 running at 2,000 rpm.
If I were to do it all over again, I would probably still go with the 6.2 diesel, I loved the way the the 80 felt with that engine, nice V-8 torque which you will never get with the OM603, felt quick off the line, again, you will never get that with the OM 603.
Just my thoughts, hope it helps.
On the other hand, I am currently restoring my 78 FJ40 and would love the OM617 in that!
Good luck with whatever you decide, if I had the OM603 though? I would give it a try.
 

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