Mercedes-Benz OM603 engine
The Mercedes-Benz diesel unit, which has been used since 1984. True, the motor was used in limited quantities, mainly on the W124, W126 and W140 models.
Description of OM603
The volume of this engine is 2996 cm3. It was an engineering marvel in its day, a revolutionary design over the earlier 5-cylinder OM617. The new motor was capable of delivering up to 148 hp. with., its compression ratio was 22 units.
Several versions were released, including turbocharged ones. The latter were exclusively sold in the USA.
The engine operates according to the following scheme:
- one camshaft and turbopump are driven by a double chain from the crankshaft;
- the oil pump is controlled by a separate single-row circuit;
- the camshaft acts on the valves using special bucket-type pushers;
- valve adjustment is automatic;
- fuel injection is carried out directly into the chamber;
- in the injector, a pump from Bosch with a mechanical regulator and vacuum control was used;
- pre-heating of the motor is provided, carried out automatically by glow plugs.
| Manufacturer | Daimler Benz |
| Years of production | 1986-1997 |
| Volume in liters | 3,0 |
| Volume in cm3 | 2996 |
| Fuel consumption, l / 100 km | 7.9 – 9.7 |
| engine's type | Inline, 6-cylinder |
| CO2 emission in g / km | 209 – 241 |
| Piston stroke | 84 mm |
| cylinder head diagram | 2 valves per cylinder/OHC |
| Compression ratio | 22 to 1 |
| Turbocharger | No (.912), Yes (.96x, .97x, KKK K24) |
| Fuel system | Injection |
| fuel type | Diesel |
| output power | 109 – 150 hp. (81 – 111 kW) |
| Torque output | 185 Nm - 310 Nm |
| dry weight | 217 kg |
| Power kW (hp) | 81 (109) 4600 rpm; 84 (113) at 4600 rpm |
| Torque in Nm | 185 @ 2800 rpm or 191 @ 2800 - 3050 rpm |
| Years of production | 04 / 1985-06 / 1993 |
| Vehicle in which it was installed | W124 |
| Power kW (hp) | 106 (143) at 4600 rpm or 108 (147) at 4600 rpm |
| Torque in Nm | 267 at 2400 rpm or 273 at 2400 rpm |
| Years of production | 01 / 1987-03 / 1996 |
| Vehicle in which it was installed | W124 300D Turbo |
| Power kW (hp) | 106 (143) at 4600 rpm or 108 (147) at 4600 rpm |
| Torque in Nm | 267 at 2400 rpm or 273 at 2400 rpm |
| Years of production | 1987 |
| Vehicle in which it was installed | W124 300D Turbo |
| Power kW (hp) | 110 (148) at 4600 rpm |
| Torque in Nm | 273 at 2400 rpm |
| Years of production | 02 / 1985-09 / 1987 |
| Vehicle in which it was installed | W124 300SDL |
| Power kW (hp) | 100 (136) at 4000 rpm and 111 (150) at 4000 rpm |
| Torque in Nm | 310 at 2000 rpm |
| Years of production | 06/1990-08/1991 и 09/1991-08/1996 |
| Vehicle in which it was installed | W124 350SD / SDL and 300SD / S350 |
Typical malfunctions
When developing the OM603, engineers paid special attention to emissions control. In the US, regulations were tightened, and a diesel particulate filter had to be created. It was installed on the cylinder head, which did not allow for a long time to use only lightweight aluminum heads that came into fashion. The diesel particulate filter also interfered with the turbocharger, which was easily damaged by trapped debris. Versions of the 603 with this filter were sold in the US during the period 1986-1987. However, the dealer removed these traps free of charge at the request of the car owner, and also repaired the damaged turbine if the damage was caused by a diesel particulate filter.
In a word, in 1990 the idea of using a particulate filter was completely forgotten. The cylinder heads were overhauled, as they were still too susceptible to overheating and cracked quickly. A new generation of OM603 comes out with more torque and power but less low rpm. Another turbocharger is installed, more efficient, which accordingly increases engine power. However, despite the correction of problems with the cylinder head, another malfunction appeared - an early damage to the gasket and oil getting inside the first cylinder. This also led to increased oil consumption. The problem is caused by weak fixing rods of the head.
Another typical problem with the OM603 is strong engine vibrations. This causes the crankcase screws and bolts to loosen. The latter enter the oil pump or clog the channels, which ultimately leads to oil starvation, bearing damage and broken block rods. Timely maintenance helps to eliminate this problem.
Cars in which it was installed
The following car models were equipped with the OM603 engine.
| E-class | station wagon, 1st generation, S124 (09.1985 - 07.1993); sedan, 1st generation, W124 (11.1984 - 07.1993) |
| E-class | restyling 1993, station wagon, 1st generation, S124 (07.1993 - 04.1995); sedan, 1st generation, W124 (05.1993 - 09.1995); station wagon, 1st generation, S124 (09.1985 - 07.1993) |
| G-class | restyling 1994, suv, 2nd generation, W463 (07.1994 - 06.1998) |
| S-class | sedan, 3rd generation, W140 (01.1991 - 09.1998) |
| S-class | sedan, 3rd generation, W140 (04.1991 - 09.1998) |
| Epoxy | I want to find a G class suitable for myself with the OM603 engine, I didn’t find any information on the mechanics on the Internet about this engine, I have this question: Who had a Gelik with such an engine, please tell me how problematic this engine is. and is it worth taking Gelendvagen with such a motor (my goal is not to pile on) |
| Vadka69 | it’s different from the simple 2.9 high-pressure fuel pump from Lukas (not in-line but rotary) and the moment there is much larger (it was put on middle-class trucks) |
| Cyril 377 | 603 is one of the best motors. High-pressure fuel pump is fashionable to change. I advise. |
| Nikolay I | Regarding the first main question, I can say that all naturally-aspirated diesel engines in Mercedes are reliable, there are unlikely to be any questions. We now have a naturally aspirated OM603 on our Gelika from 1988... how long it has already run before, who knows, and now it has been running on our Gelika for three years... No one has climbed inside it yet. 2016 - 1988 = 28 years... But should you take Gelik or not... it’s up to you to answer it yourself, why do you need Gelik. With your engine, Gelik will maintain its 110 km per hour, but not to the point of “fast” overtaking on the highway. |
| Epoxy | Displacement [cc] 2996, Rated power [kW (hp)] 83 (113) at 4600 rpm Rated torque [Nm] 191 at 2700 rpm since I'm new I was told what it is OM603 |
| 5002090 | I used to have a turbo like this. Proezdil 4 years without complaints, the main thing is to change the oil on time and not overheat (very afraid). |
| Sunny | yes, it’s 603, I don’t remember beyond the number 969, it seems to be very reliable, unpretentious, but it doesn’t drive, and if you turn on all the locks, it doesn’t have enough power, but it’s more reliable than the 603 turbo, I went through the turbo once a year until I stopped turning it, now for me the turbo has become too reliable for five years now, I haven’t even unscrewed a couple of spark plugs, just changed what else did you want to know about it? , but the repair is not complicated, it’s just hard to move everything heavy alone |
| Volodde | The first thing you need to do is check the compression when cold (should be at least 20), then pay attention to how it starts (should be from the first “push”) and run smoothly at slightly higher revs, then the revs should drop on their own. If everything is as I wrote, then everything is in order with the engine and fuel injection pump. What problems could there be: 1. GB. He is very afraid of overheating and is far from new. It is practically impossible to repair, a new one is only made to order, in the region of one hundred square meters. 2. Injection pump. It is easier to treat, but there are few specialists with normal equipment. 3. Compression. Old age, does not like boring. 4. Pre-chambers and seats for them, but this applies to GB. Watch out: viscous coupling (overheating), change the oil more often, in general, observe all recommended operating conditions - in this case everything will be fine. |
| Eric68 | compression 20 is the engine is almost dead |
| Stepanov | I decided to rebuild my motor. I took it apart, took my head for crimping - a crack, I buy a second one, for crimping - a crack, I buy a third one - a crack. I spent 4500 rubles only on crimping and gave up the idea. I will put 612 or 613. Before that, the motor was completely sorted out in 2007, the motor has seen a lot in its lifetime, but now it is more expensive to put it in order than to buy a 612 assembly. Wild consumption, 18-20 liters, though on 35 wheels |
| Jeka | I've been going for 5 years. The motor is called 603.931. It differs from 603.912 (passenger car) by the presence of a deep sump and an extended oil intake, the absence of an oil level sensor, different crankshaft pulleys and pumps, the presence of an oil thermostat with a radiator, the presence of a corrugation on the generator, and that’s it. Although I have a suspicion that the injection pump on the 931 is still configured a little differently. In any case, the numbers were definitely different. Features: 1. it doesn't move at all. Still nothing until 60-70. Then it’s very sad. If there are mountains and a heavy trailer, you will be driving in second gear, roaring and smoking. 2. maximum speed - 140, on Vladov springs - 125, but if you load it, it will go faster. In general, the lower he sits, the faster he goes and vice versa. There is a similar relationship with wind. 3. consumption 70-80 – 9 l., 100 km/h – 11, city 15, winter 20. 4. in principle, probably one of the most reliable engines, because it’s stupidly simple. There are no additional radiators, valves, brains, etc. 5. Maintenance is very easy, you can crawl and reach everywhere. Everything or almost everything fits from the 124th. 6. Normally handles high speeds. You can easily turn it up to 4-5 tons, it runs without consequences on any diesel fuel. Someone even poured dark stove into it, but the injection needs to be adjusted. 7. His head is a sore subject. Aluminum does not have a fatigue strength limit like steel, so on 20-25 year old engines, a crack in the head is a common occurrence. The question is how critically its presence affects the heat dissipation. I solved the problem by installing additional. pump and I drive without problems. I wanted to put 605.960 instead, but apparently I can’t find a deep sump for a 5-cylinder engine and will put the 606th. I already bought a pump... |
| Eric68 | automatic or manual gearbox? |
| Jeka | I have an automatic |
| Vasiko | That's right. If you have such a new motor, then its lam, with proper operation, it will run. We have 602 engines, essentially the same, only five cylinders (on beads) of 700 t.km each. went out, if you believe the speedometer One is still in the economy on the go. |
| Eric68 | Yes, it’s quite sad... he’s more fun on the mechanics. |
| V81 | I have experience in owning a diesel gelik 350 turbodiesel ohm 603. If the engine is normal, not killed, it will drive without problems, of course, if you drive calmly! does not like speed and under a long load (protracted rise) starts to warm up and then cracks appear in the head! accelerates for a long time, but accelerates!)) 100-120 cruising speed on the machine. very simple without electronics, you can repair it yourself if anything, consumption is 15 liters in the city, oil consumption is 2 liters per 10000 km |
| Yurok | I also warmed up .. until I thoroughly washed both radiators with a karcher, especially it was clogged from the conder, don’t be lazy, disassemble the muzzle, and it won’t hurt to check the viscous coupling for hot |
| V81 | Everything is clean there, the visco clutch is also a new engine, it works clearly without problems, but all the same, when the temperature rises uphill, and only after I installed another pump from 603 5-cylinder 2.9, I think the blades are made completely differently there! Stopped warming up! |
| Sunny | take it to a radiator man to clean it |
| Yurok | SIMPLY! The pump came to me, so I had to grind the impeller, because. touched the block. I also filled in yellow antifreeze, because. highest boiling point. When the coolant boils, the heat removal is disturbed, because instead of a water jacket, a steam-air jacket is formed and the HPG comes in a skiff (((if it’s already boiling, don’t go off the beaten track, otherwise it will jam and you’ll turn the shaft, just stop and wait until the tamper drops. |
| Efim | And a new radiator is better for an old motor, the heat transfer efficiency is an order of magnitude higher than that of a 20-year-old one. Checked more than once As a rule, the middle of the radiator is overgrown with deposits and the permeability and heat transfer through clogged cells is reduced. Washing inside aluminum with chemistry is fraught with leakage |
