or a link where i can find out more info ?

 

I would definitely recommend byung an E with an M103 engine (2.6 or 3.0 liter).
Of course, the 3.0- and 3.2-liter M104s produce more horsepower. They also develop more torque, but at higher engine speeds (RPM), due to the added resistance of the 24-valve train, so M103 engines, with their 12 valves, actually have more low-end pull (3000 rpm and lower) and thus give slightly better driveability, especially in town and on acceleration form lower speeds.
I guess one of the known issues with M104 is thw wiring harness. I'm sure many friends here can tell you all about that. Personally, I love my M103 engine []
Hope this helps,

Shady

 

Also, for what ever reason the M104 engine parts cost Way more then the M103's. A lot of the 104 #'s are preceeded w/ WA which usually signifies AMG.. Not sure why, but it makes major rebuilds of those engines nasty!

Jonathan

 

The m104 ist the engine that was used in the w202 c36amg...
Ist the first AMG-engine in the history of Daimler AG...

 

The M103 engine is a true legend. It went in no less than five Mercedes models: 124, 201 (190 2.6), the W126 S-class (2.6 and 3.0), the 300 SL (107), and the G-class.
Did I leave anything out?

Shady

 

M103 for smoothness, quietness, easy "drivability", easier maintenance.

M104 for potent upper rev range and a magic sound when working hard (late HFM version).

I regularly drive both my '90 300TE (M103) and my father's '93 E320 coupe (M104). Whilst the E320 offers good performance (especially with 5-speed auto) and a lovely sound when working hard, it is intrusively noisy for daily driving. Its power delivery is not as progressive and it is possible to feel the points where the camshaft timing and inlet manifold tuning changes. The 300TE, whilst not as potent, offers smooth and progressive power delivery and is almost silent.

 

The 300TE, whilst not as potent, offers smooth and progressive power delivery and is almost silent.

... and easier and less costly to maintain, I might add.

 

Got to agree with Greg....when the M104 comes on Cam at 4000 rpm, what a noise!. A great straight 6 howl....lovely[]

I can see merits in both engines, but as a favourite, I just love the M104 which was found in just as many Benz derivatives as the M103, namely W124, W202, SL, S Class and W210.

Just out of curiosity, whilst I have read of many US forum members having problems with the wiring harness, I rarely hear of members of other Benz forums in the UK having wiring harness problems on the M104 engines and for that matter other owners in Northern European countries.....maybe our damp climate stops the harness from becoming brittle!

[]

 

some mentioned in another thread that the m103 causes premature value degeneration and higher than average oil consumption, can any one confirm this ?

 

I'm sure someone else can elaborate more, but the main pontification I've seen several times had to do with the single-track timing chain.
As for oil consumption on the M103, I had that problem recently, and it was all due to bad valve seals. Once I had those replaced, I still have yet to lose one cc of oil. But generally speaking, as far as I know, all 103 straight sixes and the "tilted" (as opposed to upright fours from yore) four-cylinders had to consume some oil between changes. I recall one 124 user's manual I saw saying that the 2-liter engine typically consumes half a liter to one liter of oil every 5,000km.

Shady

 

The question of perspective has been well answered above so I will leave that one.

The M104 began around mid 1991 forward I believe, at least in North America.

Aside from the standard 12v 3.0 I6 and 24v 3.2 I6. Both the M103's and M104's have their problems, including their variants.

My personal choice of the two would be the M103 12v 3.0 I6 because I think it is far more durable than the M104's.

-CV

 

the 104 was first introduced in the 300CE. late 1989 i think. then the 300SL R129. 1990. then the 140 in 3.2 liter guise 1992.

i like the early 104. 7000rpm, mechanical injection ala 103, 217 horses ( i think.)

for reliability i guess the 103 is the one to have, as long as you realise that you will need to get the head rebuilt just after 100000miles to cure an oil consumption malady. but its simpler and therefore more "reliable" than the 104s.

 

Single row timing chain is not an issue on the M103 (6 cyl), only on early M102 (4 cyl) and early alloy M116 (V8). On the M103 it should last the life of the engine. Oil consumption (not caused by leaking head gasket) is usually easily fixed by replacing valve stem oil seals (which can be done without removing head). Early M103s did also have a problem with oil consumption due to premature valve guide wear (head must be removed to replace guides).

 

i like the early 104. 7000rpm, mechanical injection ala 103, 217 horses

Amen!
230 horses without the cat (UK spec), smooth power (no variable cams), no wiring issues, less weight than 3.2, more stable idle, incredible noise at high revs[]

 

cap'n Jasper - 10/29/2004 8:06 PM

i like the early 104. 7000rpm, mechanical injection ala 103, 217 horses

Amen!
230 horses without the cat (UK spec), smooth power (no variable cams), no wiring issues, less weight than 3.2, more stable idle, incredible noise at high revs[]

I believe you will find that all M104s had variable timing on the inlet camshaft. Please correct me if I am wrong but I have just checked the factory shop manual and it refers to the camshaft adjuster on both the 104.98 and 104.99 engines.

 

The 300-24v does not have variable valves.
The 320 does.

 

cap'n Jasper - 10/30/2004 7:59 PM

The 300-24v does not have variable valves.
The 320 does.

I have checked again. All M104s have variable inlet camshaft (valve) timing. The adjuster is mounted on the front end of the inlet camshaft and operated electrically (hydraulic oil pressure does the work). The HFM (2.8 & 3.2) version also got variable resonance inlet manifold which the CIS (3.0-24) version did not. Perhaps this is what you are thinking of. The CIS version also has a high voltage distributor driven by the front end of the exhaust camshaft. The distributor was not required on the HFM (2.8 & 3.2) versions due to the use of three ignition coils.

 

I stand corrected[]
Looks like you are correct. The 3ltr is definitely much smoother though the revs, the 3.2 has a pronounced 'step' at about 3500rpm. My vote still goes to the 3ltr 24valve(with it's variable cam timing[])

 

But oh, that "step" is very cool. My guess is that begins the steepest part of the torque curve and man does it launch the M104! Even the wagon!

 

Is it the case that the variable valve timing allows the engine to redline at 7000rpm on the 300-24 M104?

The extra 1000 rpm just keeps the power surging on like it is "back to the future" time!

 

cap'n Jasper - 11/4/2004 2:01 AM

The 3ltr is definitely much smoother though the revs, the 3.2 has a pronounced 'step' at about 3500rpm. My vote still goes to the 3ltr 24valve(with it's variable cam timing[])

Cap'n Jasper,
I suspect the "step" in the middle of the rev range which I too have noticed in the 3.2, may be the point where the inlet manifold tuning changes. There is a butterfly valve that can open to form one large chamber or close to form two smaller chambers. This variable manifold tuning does endow the HFM engine with more low down torque than the CIS (KE) engines.

Apial - 11/4/2004 6:10 AM

Is it the case that the variable valve timing allows the engine to redline at 7000rpm on the 300-24 M104?

The extra 1000 rpm just keeps the power surging on like it is "back to the future" time!

Apial,
The variable valve timing does allow for better cylinder charging across the rev range however I believe the rev limits and recommended engine speeds are determined more by what gives an acceptable margin of safety and engine life versus usable power and torque characteristic. The M103 remains turbine smooth and will happily rev beyond its 6,200 recommended limit, however at this point you are on declining points on the torque and power curves.

The 3.0 M104 produces its peak torque and power slightly higher in the rev range so the recommended limit was raised to 7,000 despite this engine essentially sharing bottom end components (and bore and stroke dimensions) with the M103.

With the 2.8 and 3.2 (HFM) versions of the M104, the torque and power peaks were again moved lower in the rev range, allowing the recommended rev limit to be moved down a little.

A similar situation exists with the 4-cylinder M102 which is effectively a shortened M103. Here, the recommended rev limit was only 6,000 due to the M102 producing its power and torque lower in the rev range than the M103. Being a four, the M102 does not exhibit the smooth, free-revving character of the M103 six. The M102, particularly in 2.3 litre form, is much happier slogging along at lower engine speeds making use of its good torque characteristics. Of course, there were also the 16-valve versions of the M102 which displayed a much peakier characteristic with a higher rev limit to exploit their top end power as with the early M104.

 

I did not notice how old this thread is/was but here is my situation

I have a '91 300e, 3.0 m103 with 300k miles... burns about a quart or more per 1000 miles...

I am a new tech, so I can work on it, but I need some advice on performance...

I would like to up the comp ratio ( shave head if possible and if so how much), def a hot cam, and I will rebuild the fuel system. Also I will do some porting and polishing... but the bottom end will remain untouched.

Need some advice and direction

thanks,

Kyle

 

let me tell you something about engines.
so: M 102 you can find on 200 sience 1.85 till 8.86
200 sience 9.86 till 5.90
200E sience 9.88 till 8.92
230E sience 1.85 till 8.92
260E sience 1.85 till 8.86
M 103 you can find on 260E sience 9.86 till 8.92
E300 sience 6.93 till end of production
300E sience 9.86 till 6.92(just for 4MATIC auto tranny)
M 104 you can find on E280 sience 6.93 till end of production
280E sience 9.92 till end of production
300E-24 sience 9.89 till 8.92
E320 sience 6.93 till end of production
320E sience 9.92 till end of production
M 111 you can find on E200 sience 6.93 till end of production
200E sience 9.92 till end of production
E220 sience 6.93 till end of production
220E sience 9.92 till end of production
after i`ve said that if you want to make a comparison betwen the engines you have to pick two engines from different modell but with the same displacement so that the camparison be right. why i`m saing that? because you can find on mercedes different types of fuel feeding like( 175 CDT, 2E-E, KE- Jetronic and HFM) and different numbers of valves like(8, 12, 16, 24).
so it is hard to tell wich one is better, they are all best in their ways, in fact all benzes engines are great as they stand as an german engenering.
but it is more likely to enconture problem with an 24 valve engine than with an 12 valve. that means that the comparison can`t be done because of the major difference betwen them.

 

^^^he nailed it

you really cant do too much to these engines with cams and compression and heads to increase power. they were designed very holistically, and taking parts from one to use on another reduces the "wholeness" of them.

your best bet, is to very very slightly increase the compression with pistons. you are unlikely to find a cam. but you might be able to use the early 104 head since the bottom end is the same. iirc the only real difference on the blocks was something to do with the timing chain, and perhaps and extra oil gallery for the camshaft advance mechanism. other than that, i believe they were the same.

however, the jetronic engines (mechanical injection) dont have knock sensors, so you cant go buck wild with increasing compression. the later HFM engines do, but they are more complicated as they have the variable inlet as well.

if you can do the work yourself, why not replicate the 3.6 liter AMG engines? proven methods, with essentially the same components.

 

is it just me or does this thred rock?!!!!

should be a sticky, oh yeah, i forgot we dont have any mods to do that in the 124 section!!

 

i don`t want to argue with you but i don`t belive that you could replace the head from an M103 to an M104.

 

I cna do anything to the car, but I am having trouble getting answers about what to do.

What would it cost to build an AMG engine?

I am basing my power goal on the old BMW m20 b25 engine... People build them to 2.8 L with 11:1 comp ratio, hotter cam, headers, port and polish and get 285 at the crank... I would think the Benz 3.0L would be able to produce 250 with just a cam, P & P and headers...