as someone said before it is not the labor that is killing us it`s the parts. if you don`t have the parts neccesary to modify an engine then you can`t modify it. and you all know how hard you find tunning parts for benzes.

 

okay

dump a twin turbo set up on the m103 a la Turbo technics...300 odd hp !!!

that would be my route to more power.....2 turbos aggghhh, make them big! whooooosssh

 

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

Yes. R129 300SL. So that`s six!

 

Had me sixed there

Shady

 

I believe here in the states the overall higher ambient air temps. may play a role in the "toasting" of the underhood wiring especially on the V8 saloons (W124 and W210) rarely a problem on older M103 engined motorcars.

190E
400E
500E
C240

 

Engine swap M103 to M104

I know this is a old thread but I'll try anyway

I now have a M103 3L 12v in my car, and I'm soon going to put in an M104 3L 24v. What I need to know is if I can use my standard wiring harness or if I have to get all new wiring from an M104 3L 24v car. I have the black box for the M104.

 

All I got to say is between owning both a 93 190e 2.6 and a 96 C280
both good body styles and great handling cars
but there is no comparison on acceleration

Wouldn't mind getting my 190e back and putting in a M104

 

I owned a "88 300E which was great. Then I got an '86 300E, those both had the M103. When I got a '90 300CE it was funny, cause when I bought the car I saw how the engine looked different but it didn't register with my mind what I was looking at. It wasn't until I ran the VIN on the russian site that it told me I had a M104 with 4 valves/cylinder, variable valve timing and dual exhaust manifolds, and the site also says it's an AMG 3.2 engine although I didn't think the 3.2 M104 was out yet in '90. But everything else on the russian report is correct. So when I was driving the car one day shortly after I bought it, I thought it would be interesting to see what the difference in head, valves and exhaust etc. would be. Until then in terms of power this car seemed somewhat fairly similar to the others. I was going about 30MPH and floored the gas pedal. Three or four seconds later I had to let off, as I was going so ridiculously fast in a short period of time that I'm sure I said a swear word in amazement. I tried this out several times after that, and the car just really impresses the sh@t out of me. I had to show some of my friends, "Hey watch what happens when I do THIS", and everyone agrees it performs very impressively.. not supercar status, but still fast enough to be considered a "sleeper". The 88 I had ran extremely well, and this M104 may or may not have a higher top speed than the M103s I've owned, but for the excitement of driving or when you are passing someone this engine shines, it passes other cars when I want to, with very little effort, and it seems as if it's clairvoyant and all I had to do was consider passing and -Zing! -it happens. It purrs pretty dam smooth, like a Benz should, and if at a green light I want to take off "really" fast which isn't too often anyway, by kicking the pedal to the floor it makes the trans decide to use first gear and wow, That sure seems to be the ticket. I decided I like having the extra valves, and the DOHC has less valvetrain. The engineers really did a great job with designing.. I know there is a first gear start mod you can do so that it will always take off in first, ...I may do that sometime.. This thing has got to run pretty well to impress me as I used to be a big V-8 power junkie, and now I'm happy with a six. Having owned both the 103 and 104, I have to say I like them both. With Mercedes, the engineering & build quality is there; all ya gotta do is take care of them.

 

I'm not sure about the 1st gear mod
but from what I understand is that the 4 speed auto (722.4)
normally starts in second, but when you fully press the pedal to the kickdown switch it will start in 1st

(please anyone chime in for a correction if I'm wrong)

 

Was that the first auto transmission on the six-cylinder 124 (from '85 to about '89)? That's true, but if you shift from D to L and back to D in standstill, it will take off in 1st without the need to use the kickdown feature with WOT.

 

I haven't driven a 124 with either M104 iterations (3.0 and 3.2), but I would suppose that the M103 has a little more low-end grunt, and therefore is a little smoother for urban driving. All things being equal, ulti-valve engines (that is, more than one camshaft and two valves per cylinder) tend to suffer from low-RPM torque deficiencies compared to single-camshaft, two-valve counterparts, due to increased valvetrain drag.

That said, I would still get one with an M104 should I decide to get another 124 (and considering the severe state of 124-sickness I'm going through right now, I just might, pending my annual bonus!) The M103 in my old 300E tended to get disinterested at higher RPMs. And then there is the reliability and service costs issues of the old K-Jetronic system to grapple with.

As for the 1st-gear takeoff mod, I don't think you really need to bother with the actual mod, because you can tell the transmission to take off in 1st at will, even without using kickdown. The procedure is simple: while in standstill, shift from D into L and back into D again. Once you step off, the transmission will have shifted into 1st instead of 2nd, and you're good to go.

Oh, and a small edit: "With Mercedes, the engineering & build quality was there;" just drive (not own) a '99-06 S-class for a few days and you'll know what I mean.

 

Yeah, a couple of people found it hard to believe that little tidbit until I actually showed them how it worked.

If you ask me now, I think it was a rather stupid technique. It would've been better if they had designed it to default to 1st at throttle application that exceeds a certain level. But then again, we're talking early 80s technology here, when full electronic transmission control was quite unheard of, so they must've had to resort to mechanical means of gear selection.

 

If you consider that not everyone is racing from start then its pretty smart for reducing fuel usage.

If you consider that some people drive in the winter and snow on the road hinders traction, then its bloody brilliant.

 

I would have to agree on that point
because of the ratio, 1st gear really isnt needed for good fuel economy and,
of course for some of us that have to drive in the snow during the winter,
it helps there also

though the 722.6 transmission does offer the S & W switch for that reason (plus the added 5th gear)

 

I never thought I needed 1st gear on my 300E 2.6 until I drove to Denver. I still didn't think I needed it, but I could see a valid case for it for those people who live in mountainous regions.

My E320 seems to start in first gear. I will have to note how many gear changes it makes.

 

Something to note, the M104 has double overhead cams with the 4 valves, so there are no lifters & pushrods in the valve train. So you get the better air moving capabilities with the 4 valves, without the drag of the valvetrain

 

There is definitely MORE drag in the m104 valvetrain compared to the m103. That's what an extra cam and replicate set of valves (compared to a 2 valve engine) gets you... and why the m103 is "electric motor smooth" and more rev-happy (definitely happier above 3k rpm) than its 4 valve counterpart.

 

I really liked the M104 in my C280 I once had

even better in the M104 3.0 24v of the 300ce I have now
the power just keeps going all through the 7k red line

 

The two are different animals. Just as much as I find the high-rpm surge of my E320's M104 intoxicating, I also loved the more linear nature of the M103's torque curve in my old '87. I would say the M103 is more of a daily-driver, inner-city workhorse, while the M104 is the better illegal-speed, balls-out cruiser. But one thing is for sure: such is the nature of progress.

 

VIN on the russian site that it told me I had a M104 with 4 valves/cylinder, variable valve timing and dual exhaust manifolds, and the site also says it's an AMG 3.2 engine although I didn't think the 3.2 M104 was out yet in '90. But

(Did AMG build my engine??)

 

i find it that my 2.6 has a nice torque sruge at 4000rpm wide open throttle. If i floor it on a stop sign, it will start in 2nd gear and stasrt accelerating and before shifting into third, it will peel the tires which is pretty fun.. thats how i know if it runs strong.. i rememeber i lost the ability to peel tires once.. and then i got new spark plugs and now i got it bak.. this motor is a beast.

 

As owner of both, I must admit the M103 is growing on me. Things is not: smoother than the M104, more powerful than the M104, lower revving than the M104, more economical than the M104. What it is: once tuned and running well - arguably the lowest maintenance and strongest gas motor ever to come out of MB. a high revving beast on the highway (but loves it), and 95% of anything that will ever go wrong with it can be fixed by the OEM tools that come in a bundle with the spare. I honestly think at some point in the near future I will sell the wagon and drive the SE. Always been a retro kind of guy.

 

thought I'd try a different approach to comparison

so I sold my 300ce with the 3.0 M104
bought an Alfa Romeo 164LS with a V6 24v 3.0

let the learning begin

actually a nice comfortable drive
but front wheel drive and some torque steering under hard acceleration
it does have a switch for "sport mode" which is nice
also an "ice" switch for 2nd gear starts in the snow

I'm definitely the only person in my area with one of these cars
went to get an alignment and the the guy at the counter said; "an Alfa WHAT?!"

 

I know this is an older thread but I figured I'd post something. Gotta love the 103 engine, my 92 300TE 4M with 230k on the clock still runs strong as ever! Love the sound as it revs up to redline, smooth as ever like a jet turbine spinning up to speed.

 

Wow this thread is 6 years old now, the 103 is a great motor i remember my first one 91 300e first day i got it i took it home 700km driving on the highway looked down at the speedo and i was doing 160km 100miles and didn't even notice it that engine was so smooth and vibration free. Got a e320 with a 104 motor still very nice but head gaskets are weak.

 

Wait until you get into a M104
You'll be surprised

But I get bored of having one car too long

 

I probably already commented in this thread, but...
I drive several 103s and several 104s every day, and very much like all of them...
but there is no comparison. I prefer the 104's added hp.

Yea, maybe it is a bit higher in the rpms before I GET that hp advantage, but when looking for it, it is there.

I won't dispose of a car due to the 103 but, when looking for new toys, I significantly value the 104.
it.

 

I've owned an M103 car for a few weeks now and I'm pleased with it.
-MPG. Don't know how it stacks up to other models, but I'm pleased with low 20s mpg in a big wagon
-Space. The last few cars I've owned were BMWs iwth V8s shoved in. The space in/around the engine to work on it is great
-Simplicity. Easy enough that you could tell what is what glancing at it once.

 

Yea I'm surprised of the MPG with the V8s. Both my 93 MBZ 400e (4.2 V8 275 HP) & 93 BMW 740iL (4.0 V8 282 HP) have a 2.93 dif so they get in the mid to upper 20s mpg on the freeway.

I do like my 740iL over the Merc because of 5 speed auto gear box (vs 4 for the Merc) with the selective 4 speed sport mode. Then of course the extra HP even though it's a smaller displacement. The electric rear sunshade and individual coil pack vs the Merc cap & rotor set up (they did change in 94 with coil packs and badged E420)

The 18x9.5" rims definitely help in the corners

 

Hello everyone,

Just read this old thread and thougth I'd put in my 2 cents:

My '86 300 SL has a M103 under the hood and runs very smooth. Sure it's not as fast as the 104, but for a 25 yr old car, racing is out of the question (with what is out on the streets today). This is a convertible cruiser and as such, this engine seems to be easy to work on and generally trouble free.

Only complaint is that due to it's euro spec, the water pump is slightly different (part #) than the US version, but way more expensive !! Something Im going to have to tackle when I have to replace the timing chain.

Here's a few pics:

 

Looks good with those rims and the euro headlights :thumbsup: