Engine life is always dependent on servicing.

I've put pistons & rings in cars with 50K miles & seen other cars with 300K+ that were NEVER apart & still no engine issues.

Early 103's seemed to LOVE valve guides & seals. Replacement parts were better.

Some people HATE CIS cars & others hate EFI cars.

A good 1992 300E would "most likely" cost less to maintain that a 1993 300E with a M104 engine.

The 1994 & later do have a ventilation dust filter system that is better for the driver.
I also like the body up-dates on the 1994 & 95 models.
Make sure on a 1993 & later car that the engine & starter wiring harness has already been replaced!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

2nd generation 104 motors (i.e. HFM 2.8L / 3.2L) with proper care don't seem to need valve jobs. They have head gasket issues but I don't think anyone really knows how long they will go - which is a good sign given that they've been out for 16+ years. Recent Star magazine had an article about one with 450k, no issues other than one head gasket. To me the argument for HFM 104 is the better diagnostic system - too much guessing on a CIS.

It's well and good to talk about the engines, but most W124 are also ready for some expensive transmission work and some expensive HVAC system work, too. Suspension work, too, if it's a wagon.

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

The '91 has 170K and has only had tranny issues. Engine has been maintained and is solid. Burns half a quart between 3k oil changes. It does suffer from poorly performed body work, though.

The '90 has 295K miles and has had the same tranny issues as well as valve guides and seals replaced. It sucked oil at an alarming rate until the valve work was done at about 250k. Now it drinks about a quart between 3k oil changes. Decent for the mileage.

These engines burned a little oil even early in their lives at high RPM. I saw vapor out back at full throttle and I'm quessing it was oil and fuel. CIS seems to over-fuel as a safety measure. I much prefer EFI on gasoline engines.

That's good service from a relatively cheap car in my opinion. Auto trannies suck in general so I'm not surprised by one replacement and one rebuild.

I'll take my OM617 powered cars over the gassers any day. I've got a W220 S430 and even it usually sits in the garage while I drive my old, trusty '82 300D. It has character that the W201's nor the W220 could ever dream of.

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Best Regards,
Sam

'76 280 Time Capsule
'00 S430 Long Trips
'91 190E Seeing how far it will go. 366k
'04 American Eagle Motorcoach

I like the M104 as used in the '93-'95 124 cars. I've found it reasonably easy to diagnose and work on, not that mine has required all that much attention in 6 years of ownership. Plug changes are trivially easy. There is no cap or rotor. The water pump is a bit involved, but seems to be easier than the 103 engine. This past weekend I changed the fan belt in less time than was required for the topsider to drain the oil.

Just make sure the head gasket and wiring harness have been replaced on any candidate car. Might be worth asking after the ETA as well.

- JimY

My 1996 E320 with M104 engine is approaching 150K, the only major issue in my ownership was the broken water pump. Hope to reach 200K without big problems.

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1996 E320 since 1/16/08, 171K miles as of Feb 2011

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1989 300CE - R.I.P. Dec 29 2007
Other MBs (sold): 1992 300E-24 - 1979 350SLC - 1984 230E - 1990 300CE

Thanks - this is great info. Help me out - CIS versus EFI? CIS is a mechanical fuel injector, versus an electronic (e.g. computer) controlled injector?

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1984 300D: 275,000 miles (soon to be for sale)

In search of my 1987 300D in anything but white.