Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 04-25-2003, 02:06 AM
pmizell's Avatar
Benz Zealot
 
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
Working on 104 vs. 103, how much difference?

I'm seriously thinking about purchasing a '94 E320, and considering I'm a DIY'er, I was curious as to the differences/difficulties between wrenching a 104 v a 103. I know the ignition system is more advanced, and the fuel injection is different, not to mention less space to work in the engine bay. (all of that plastic is intimidating )

For example, I've done a head gasket job on my '91 300E, and if this '94 needs one done in the future, I'm wondering if I could tackle that myself (car has 107k on it) using my current knowledge. I know there would be some differences, but would they be drastic?

Any insight appreciated! TIA
__________________
-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi
Reply With Quote
  #2  
Old 04-25-2003, 07:55 AM
LarryBible
Guest
 
Posts: n/a
I have not done a 104, but I have done a 103. In discussions that I've had including with my brother in law who is my tech at the MB dealer, I believe that if you can do a 103, you can do a 104. I think that with a 104 it is better to leave the manifold and injection on the head and pull it all off as a unit. With the 103 I found it quite easy to leave the injection in place and pull the head alone.

Good luck,
Reply With Quote
  #3  
Old 04-25-2003, 02:42 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
It might be a good idea to ask Jim (engatwork).

He did the headgasket on his E320 before he sold it to another member on this site.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #4  
Old 04-25-2003, 06:40 PM
pmizell's Avatar
Benz Zealot
 
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
Thanks guys...

For the advice. While looking at a parts catalog for the 104 I noticed a couple of things added to the 104, that the 103 didn't have. The 'mass air sensor' just before the air filter and a 'slide actuator' at the bottom of the air intake area. Do either of these have a history of failure.

Also, how does the durability of the 104 compare to the 103? (104.992) Did this engine debut in '94? If so, I guess it'd be a little premature to answer this question ... unless there is an owner out there with 200k + on the engine.

Thanks again for your help... :p
__________________
-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi
Reply With Quote
  #5  
Old 04-25-2003, 09:28 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
This engine debuted in the W124 chassis in 1993.

Mercedes didn't change the badge this year, so it simply reads 300E, even though it has the 3.2 liter engine.

In fact, all 1993 300E sedans, coupes wagons, and cabriolets have the 3.2 liter engine.

Mercedes also installed the 2.8 liter M104 engine found in successive C280's in 1993, and called this model (correctly) 300E 2.8.

I might also point out that all 1993 300E (3.2's) share the same chassis #, engine #, and VIN # as 1994-1995 E320's. All of the interior changes occurred in 1993 (passenger side airbag, flip-up armrest, etc), but 1994-1995 W124's got the updated grill and headlights, chrome strip on rear trunk, clear / red tail lights, and clear / yellow front indicators.

I find the 3.2 liter engined W124's to be far superior to the earlier M103 300E's. The M103 engine has a single over head cam, and still used the CIS-E fuel injection system, using a distributor with one coil wire and 6 spark plug wires. This is basically a mechanical injection system with electronic control.

The 3.2 liter M104 engine was used in all 1994-1997 SL 320's, 1993 W124 chassis 300E/300CE/300TE (3.2), '94-'95 E320's (W124 chassis), 1996-1997 E320's (W210 chassis), and 1992-1999 S320's (W140 chassis).

The 3.2 liter M104 engine uses a different ignition system - HFM (hot-film mass air flow sensor), fully electronic, with integrated electronic ignition and sequential fuel injection. This system combines fuel injection and ignition control in one module. HFM-SFI systems use coils that are mounted directly on the spark plugs, replacing the distributor at the front of the engine. Each coil pack provides spark to two spark plugs at the same time, one connected directly to one plug, and the other with a short high tension lead to the next spark plug. So there are 3 coil wires and 3 high tension lead wires.

HFM fuel injection systems are designed so that idle speed can't be adjusted. Idle speed is completely controlled electronically. This HFM injection system also has adaptive technology that compensates for conditions such as engine wear and unmeasured intake air and is designed to maintain driveability as the engine ages.

HFM-SFI can retard engine knocking to just the knocking cylinders, unlike EZL technology, which retards spark timing across the entire engine. This keeps the ignition timing point as advanced as possible for maximum power output.

The 3.2 liter M104 engines also have variable valve timing on the intake cam, making the torque curve broad and flat, developing HP at a much lower rpm. This makes the power much more useable and noticeable.

The M104 engines also have a superior head design. Valve guide wear has always been a problem on M103 engines. The M104 head design has minimal vave stem/quide side force [ cam-valve swipe] . Mercedes seems to have solved the common M103 valve guide problems with this far superior design and it is not unusual to see them still tight into the 200K figures.

The early 3.0 liter 12-valve M103 engines are nice, but the advancement of technology is just so great in the 3.2 liter M104 engine, making these later cars much more desireable, IMHO.

I might add, however, that some seem to believe the M104's to be more trouble prone or expensive to operate because of two very common repair issues on the early versions of the M104 engine from 1993-1995:

1. The early head gaskets were bad, leaking oil at the right, rear corner of the head gasket. Techs have mentioned that this failure is much more commone on the M104 engine than the M103. Luckily, the head gaskets have been redesigned with copper or steel inserts, and the new head gaskets don't leak.

2. The early engines (1993- early 1995) have bad engine wiring harnesses, where the insulation on the wires flakes off, causing driveability problems, misfiring, random engine fault codes, etc. Budget about $500 for a new harness.

Except for those two issues, these cars are nearly perfect, IMHO.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #6  
Old 04-25-2003, 09:42 PM
Glen's Avatar
...auto enthusiast
 
Join Date: Sep 2000
Location: Carlsbad, CA USA
Posts: 1,186
Quote:
Originally posted by suginami

2. The early engines (1993- early 1995) have bad engine wiring harnesses, where the insulation on the wires flakes off, causing driveability problems, misfiring, random engine fault codes, etc. Budget about $500 for a new harness.
Just a quick addendum to Paul's comments. Budget about $750 for the wiring harness PLUS installation. Dealer price is even higher.
__________________
Glen Tokuhara
Beauty & the Beast and the wagon that could!
Reply With Quote
  #7  
Old 04-25-2003, 09:50 PM
Moderator
 
Join Date: Dec 2001
Location: Southern California, U.S.A.
Posts: 8,508
I believe the Parts Shop price for the engine wiring harness is about $550.

A typical Mercedes inpendent shop should charge between 2.5 to 3 hours to install it for you, or you could DIY for free.
__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".
Reply With Quote
  #8  
Old 04-26-2003, 04:24 AM
haasman's Avatar
Registered User
 
Join Date: Jun 2001
Location: San Francisco, CA
Posts: 3,097
Also the 104 engines are quite fast. They pull. I am always amazed when I floor the wagon. It loves to run. The cars never used any oil (5k oil change intervals, synthetic 10-w40 oil) and when hot during the summer it always shows strong oil pressure.

The only running problem I have ever had was a little surge under acceleration which disappeared after one good acceleration run.

More horsepower and a better fuel economy than the 103's.

I like this engine a lot.

Haasman
__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 01:58 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page