m103:

3.0L SOHC, Constant Injection System, cap/rotor style iginition

50k mile head repair for vavle guide seals, unbreakable otherwise

155 hp for the US.

m104:

3.2L DOHC, EFI, Electronic ignition

Head gasket and Wiring harness one time fix.

217 hp


Are there transmission differences?

I have an opportunity to buy a 100k mile 1993 300e which is an m104, but it is wrecked. I would like to put the engine in my rather nice 1991 300e with 300k miles. My engine needs rebuilt and the transmission is acting up. Labor is no issue, but wondering if the m104 is worth the effort, or if I should just pour more money in the underpowered m103?

The M104 also doesn't burn oil.

If you are going to do the transplant your going to need the whole car, for the computers etc.

Personaly I'd just buy a newer car. You can get 1995 E320's with under 100k miles cheap these days.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I thought about that, but I have had this one for two years and everything is done. Evap which counts for a lot, interior, stereo, and the suspension is partially replaced.

My choices are to rebuild the m103 or replace with a m104, and I would have the enitre car, I think I can get it for $1000.

Your exisiting '91 has 300,000 miles and is 16 years old. I would say it that it has reached the end of it's economic life span. Putting an M104 engine in it will be no end of headaches from transmission gearing to electronics and on and on. If you are going to fix the '91 then far better to just rebuild the top end and keep on driving.

Why not look around for a '92 300E, or 93 through 95. They can be had for very little money. I just got a '97 S320 for under $12,000. Or buy a lower mileage '91 and swap that engine and transmission.

Relative to the M103 hp, it is 177 not 155. Plenty fast enough for me, 0 to 60 in around 8 seconds. The valve guide issue was a problem early on in the model. My '92 Sportline had a headgasket at around 75K I think, but no valve train work. The car is now pretty much retired due to the S320, but has 242K on it with no valve train work ever done.

Steve
'92 300E Sportline 242k
'97 S320 116k

A completely new car is out of the question, cheap to me is $1000 as that is how much cash I can part with. $5000 would require me to get a loan which is also not happening.

I would actually prefer to get an e420, but as I said a new car is out of the question for at least 6 months.

If your M103 needs rebuilding and the tranny is acting up - I would also say get a new car/loan.

Maybe try and drive the current one as long as you can until you can afford a new one.

With that mileage and the engine/tranny issue, you are looking at a lot of work and investment for a car that has done its duty, so to speak. Lots of other components waiting to go at that mileage.

I recently had to make the same choice about my 300E. Bulletproof engine and tranny, but everything else was going. She started to develop all kinds of weird issues, so I pulled the plug and got the E430.

If you must fix it, I would say stick with the M103 (177 hp, btw) and get a rebuilt tranny with warranty if possible. Good luck!

Just my $0.02.

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Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

sounds like I should just drive her till she drops.

300,000 miles was a good run.

Did you see this thread?

M104 to replace M103 possible

__________________
Chris
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired

"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon

yea. time will tell what the fate of my 300k 300e will be. I think I will just buy a toyota