Help me figure this out - M103 - Page 3 - PeachParts Mercedes-Benz Forum

JohnM. · #31 03-26-2010, 08:33 PM

Honestly, my well-tuned....M103 with a fairly low mileage bottom end, and a fresh top end has oodles of power (even at 5500ft). I believe it is very close to the factory spec'd 7.5sec 0-60.

I can't wait to take it down to sea level. Not sure why people bag on the M103 so much. Honestly the published 0-60 times for the late M104 engined cars are slower than that of the early M103. Especially with first gear start, the 300E is a joy to drive. IMO, the M103 redlining sounds ten times better than an M104 under the same circumstances. No, it's not going to blast people from the line. But 20mph rolling starts, it's going to take something with considerably more power (or less weight) to put it to shame. The M103 loves to rev and I think some people are afraid to drive it hard, but that is where it performs the best. One of the favorite parts of my usual commute is a ~1/2 mile considerable up grade portion of highway, punching it at 55, and by the top of the hill I can just touch 100mph.....it's quite fun. I think many people don't realize how nice a proper low-mileage/maintained 300E engine is.

Oracle12345 · #32 03-26-2010, 09:04 PM

Quote:

Originally Posted by tbomachines

I'm not going to buy anything exhaust-related until I get a smog test. As I mentioned earlier, there is an exhaust leak somewhere up the pipe, regardless of whether or not the cat is plugged. You can hear it alongside traffic, jersey barriers, fences, etc. when driving along, especially accelerating from a stop. It does burn a bit of oil, though not much....I've driven it about 500 miles since I got it and it is just a tad lower on the dipstick. No leaks around the engine, it is spotless.

I know the car is underpowered in terms of performance numbers but my 300SD shouldn't be able to outrun it.....I live basically on the edge of a river and after crossing the bridge, there is a massive hill on the other side. The 300E loses speed with the pedal to the floor, even after it upshifts. I think the trans needs to be tuned a bit (it upshifts to 2500 rpm, have to put it into "2" to get it to maintain speed at 3-4k). My 300SD has no problem going up that hill and that is a significantly heavier car (especially with all the crap I have in the trunk), though a bit more torque. Along with a transmission adjustment (bowden), I'll probably check/tighten up the throttle linkages too....

Idle is a bit rough and shuddery as well. I am going to go through and clean all the sensors I can, along with testing them out via multimeter and diag port just to make sure there is nothing odd going on. I've the the weekend ahead of me, might as well put it to good use!

Edit: also been getting below expected mileage...gone 120 miles mixed city/highway and it is down half a tank, haven't done the figures yet but it seems quite low.

you are experiencing the difference between a gas and diesel vehicle. A diesel vehicle will offer much better low end torque because of the design of the engine, the chemical structure of diesel. A gas engine is only 20-25% efficent and a diesel is 50% efficent in terms of combustion.

As for the fuel mileage problem sounds lambda needs to be adjusted, fuel injectors to be checked. A common place for those to leak oil is on the right side of the motor at the front because of the head gasket design. I would do a compression test and cylinder leak down test to see the health of the motor. do you know how to do a cylinder leak down test?

Zeus · #33 03-26-2010, 09:30 PM

Quote:

Originally Posted by JohnM.

Honestly, my well-tuned....M103 with a fairly low mileage bottom end, and a fresh top end has oodles of power (even at 5500ft). I believe it is very close to the factory spec'd 7.5sec 0-60.

I can't wait to take it down to sea level. Not sure why people bag on the M103 so much. Honestly the published 0-60 times for the late M104 engined cars are slower than that of the early M103. Especially with first gear start, the 300E is a joy to drive. IMO, the M103 redlining sounds ten times better than an M104 under the same circumstances. No, it's not going to blast people from the line. But 20mph rolling starts, it's going to take something with considerably more power (or less weight) to put it to shame. The M103 loves to rev and I think some people are afraid to drive it hard, but that is where it performs the best. One of the favorite parts of my usual commute is a ~1/2 mile considerable up grade portion of highway, punching it at 55, and by the top of the hill I can just touch 100mph.....it's quite fun. I think many people don't realize how nice a proper low-mileage/maintained 300E engine is.

Hey, I'm not bagging on it at all, it's a fantastic engine! My 300E went to 333,000 Km all original - zero work done on the engine. Just saying it is a tad underpowered for the chassis is all. Just MHO, not fact. I thought it was a decently peppy engine until I got the E430, which changed the entire picture. Part of the issue I think is also that 4-speed tranny. It's hard to find a sweet spot and it has a mind of its own in terms of shifting. I got tired of either slamming it off the mark to force a 1st gear start, or using the shift down and back up method at stop to get the 1st gear start. That obviously makes a big difference, but I do remember times when I hit the gas hard (like passing on a hill, etc.) and I didn't get as much power as I'd hoped for.

The diesel vs. gas is a good point as well.

I guess all I am trying to say (in a long winded way) is that perhaps there is not as much wrong with the engine, but rather it is not delivering as per tbomachines' expectations in this case?

Yours sounds rebuilt and I'm guessing that would make a significant difference compared to a higher-mileage specimen.

I've driven an M103 300E, a M104 300E and a M104 E320 and in all cases the M104 pulled significantly harder than my M103 ever did. Nothing scientific, just seat of the pants observation. Significant differences in the two.

The M103 however, has been touted as being one of the toughest I6's around. Just check out the Performance board on this forum and see what those guys are doing with them and turbos...500HP+!

That would solve the little hill problem.

tbomachines · #34 03-26-2010, 09:33 PM

Quote:

Originally Posted by Oracle12345

you are experiencing the difference between a gas and diesel vehicle. A diesel vehicle will offer much better low end torque because of the design of the engine, the chemical structure of diesel. A gas engine is only 20-25% efficent and a diesel is 50% efficent in terms of combustion.

The performance numbers for the 300SD and 300E should absolutely not match as mine do. Of course the diesel will have more low end torque but the gas engine should leave the diesel in its dust in a drag. My cars are about the same performance level...not good. I've driven a number of gas vehicles, not new to them...just new to this car.

Quote:

As for the fuel mileage problem sounds lambda needs to be adjusted, fuel injectors to be checked. A common place for those to leak oil is on the right side of the motor at the front because of the head gasket design. I would do a compression test and cylinder leak down test to see the health of the motor. do you know how to do a cylinder leak down test?

I agree I need to do some diagnostic work to fiddle with the AFR and fuel injection system. I noticed today that when I rev it in neutral a bit and let off the gas, it comes VERY close to stalling, which would indicate running a bit rich (in my past experience at least). Fuel pump is pretty loud too...crawled under there while the car was running to check it and for exhaust leaks. Cat-back is all like new, definitely replaced but with OEM pieces ($$$). All that I've got left to do is really to start picking this thing apart and check all of the sensors. Will update this thread as I do it.

Thank you for all your input!!

Edit: the line about the fuel pump was supposed to be accompanied by this bit--tried to get the fuel filter off but damn those nuts were STUCK. Had a tough time getting leverage but still....Blasted it with PB, letting it soak a bit then I'll get at it again tomorrow. Looks like the filter hasn't been changed in forever so that'll be a good thing to do for sure.

JohnM. · #35 03-26-2010, 09:56 PM

Quote:

Originally Posted by Zeus

Hey, I'm not bagging on it at all, it's a fantastic engine! My 300E went to 333,000 Km all original - zero work done on the engine. Just saying it is a tad underpowered for the chassis is all. Just MHO, not fact. I thought it was a decently peppy engine until I got the E430, which changed the entire picture. Part of the issue I think is also that 4-speed tranny. It's hard to find a sweet spot and it has a mind of its own in terms of shifting. I got tired of either slamming it off the mark to force a 1st gear start, or using the shift down and back up method at stop to get the 1st gear start. That obviously makes a big difference, but I do remember times when I hit the gas hard (like passing on a hill, etc.) and I didn't get as much power as I'd hoped for.

The diesel vs. gas is a good point as well.

I guess all I am trying to say (in a long winded way) is that perhaps there is not as much wrong with the engine, but rather it is not delivering as per tbomachines' expectations in this case?

Yours sounds rebuilt and I'm guessing that would make a significant difference compared to a higher-mileage specimen.

I've driven an M103 300E, a M104 300E and a M104 E320 and in all cases the M104 pulled significantly harder than my M103 ever did. Nothing scientific, just seat of the pants observation. Significant differences in the two.

The M103 however, has been touted as being one of the toughest I6's around. Just check out the Performance board on this forum and see what those guys are doing with them and turbos...500HP+!

That would solve the little hill problem.

Indeed. It just seems most people resign themselves to the fact that the stock M103 is never going to be fast. The transmission on mine is also quick, snappy and changes gear at the right times. If you learn the shift points (and double kickdown points) and drive accordingly, you can make the 300E look damn impressive. Mine just had a "proper" head job done, nothing too fancy. The compression on my motor is a little higher due to the fact I had the head skimmed by the machine shop the smallest bit. I looked a good ten or so 300's before choosing mine. It doesn't take much neglect over the course of just one owner.....to turn these cars into granny shifting pigs that can barely get out of their own way......

In its day the 300E was a FAST 4 door sedan. I mean the non-turbo 944 was almost a full second slower 0-60. It is not FAST by today's standards, more like QUICK.....As you said, or someone else; minivan's can now crank out sub 8 second 0-60's. But it's all in how you get there. And how reliably you can get there well past 200K.

.

I also picked up a 95 540i just recently, now that would definitely smoke the W124 for breakfast and lunch....probably similar performance to your E430. V8 sedans are a whole different animal.Boy that thing is FUN on the highway.

.......I just prefer the silky smooth high revving I6.

Sorry for the threadjack BTW.

Zeus · #36 03-26-2010, 10:16 PM

Quote:

Originally Posted by JohnM.

Indeed. It just seems most people resign themselves to the fact that the stock M103 is never going to be fast. The transmission on mine is also quick, snappy and changes gear at the right times. If you learn the shift points (and double kickdown points) and drive accordingly, you can make the 300E look damn impressive. Mine just had a "proper" head job done, nothing too fancy. The compression on my motor is a little higher due to the fact I had the head skimmed by the machine shop the smallest bit. I looked a good ten or so 300's before choosing mine. It doesn't take much neglect over the course of just one owner.....to turn these cars into granny shifting pigs that can barely get out of their own way......

In its day the 300E was a FAST 4 door sedan. I mean the non-turbo 944 was almost a full second slower 0-60. It is not FAST by today's standards, more like QUICK.....As you said, or someone else; minivan's can now crank out sub 8 second 0-60's. But it's all in how you get there. And how reliably you can get there well past 200K.

.

Yep, agreed.

I'd love to drive my 300E hard at times and that I6 sounded fantastic when you opened it up. It had a great steering feel as well, nimble yet firm. The only thing that really stank about the 300E was the stereo...

Mind you, I upgraded that as well (I wrote a DIY article for this site re: amp install).

540? Nice. I considered one, but a) didn't want to stray from my MB comfort zone and b) needed a bit more interior room (kids/car seats). Great car though, and it would likely beat the E430 all-around as well.

Cheers,
C.

Zeus · #37 03-26-2010, 10:21 PM

Quote:

Originally Posted by tbomachines

Thank you for all your input!!

Edit: the line about the fuel pump was supposed to be accompanied by this bit--tried to get the fuel filter off but damn those nuts were STUCK. Had a tough time getting leverage but still....Blasted it with PB, letting it soak a bit then I'll get at it again tomorrow. Looks like the filter hasn't been changed in forever so that'll be a good thing to do for sure.

Good luck, hope you get it sorted out!

tbomachines · #38 03-26-2010, 10:39 PM

Quote:

Originally Posted by Zeus

Good luck, hope you get it sorted out!

LOL thanks me too!

I'm sure I'll have more questions as I go through everything....

400Eric · #39 03-27-2010, 07:53 AM

I know somewhere in this thread there is info on the Euro 190 hp M103. I just can't remember which page. http://www.peachparts.com/shopforum/showthread.php?t=32224

Some info and links to videos and photos of actual 300E, 400E, 500E and 540i dragstrip experiences: http://www.500ecstasy.com/forums/showthread.php?t=6323&page=12

A video of my 400E running a 14.551: http://www.youtube.com/watch?v=sOpeNXP0sMw&feature=channel

The final word on the 540i vs. 400E/E420 debate: http://www.peachparts.com/shopforum/showthread.php?t=172171 The best info is near the end of the thread on the last page (but not right at the end).

Regards, Eric

JohnM. · #40 03-27-2010, 06:13 PM

Quote:

Originally Posted by 400Eric

The final word on the 540i vs. 400E/E420 debate: http://www.peachparts.com/shopforum/showthread.php?t=172171 The best info is near the end of the thread on the last page (but not right at the end).

Regards, Eric

My 1995 540i with the 4.0L M60 is spec'd at 6.2 secs 0-60 (AUTO). The 1993 and 1994 540's were significantly slower for some reason. Mine gets 18-19mpg around town, with a lead foot, and about 24-25mpg highway. The 6 Speed 1995 540i with a Dinan chip is exactly as fast as the 500E, and would have no problem keeping up with an E34 M5. 5.5secs 0-60 for the 6spd. I've driven both....the 6-Speed is scary fast.

PETERPNYC · #41 03-27-2010, 07:02 PM

Quote:

Originally Posted by tbomachines

Thank you much for the info guys. I am actually registering the car in CT, but the laws are not much different than here in PA. I've been thinking about it and I think that I will go through emissions just for S&Gs, since the PO passed about a year ago in Jersey (tighter emissions/inspection laws). If I fail I'll order a universal cat and have it welded in within a few days, pass will give me more time. The 100k estimation is my own, the odometer reads 81k but its going slow. 100k was just a rough number from the condition the car is in. Guess I'll see where this leads me.

Turbo idea is a long-term one...would be converting to EFI (probably megasquirt) and all the fun stuff associated with that. Interesting post on the performance paddock section notes that the 350SDL is basically a turbo manifold that will fit the M103 for a T3/T4 turbo. But, as the #1 rule in modding states, need to get everything working 100% before any mods.

I am not sure if this will help but did you look at coils for arcing. Mine cause all kinds of problems at under 2000 RPM . Just a cheap thought . I also went nuts and drew no codes Spent 1k and it was $120 parts
Worth a look IMHO.

Its just that I very seldom see anyone mentioning coils for anything intermittent, under load , or in any other way obvious , and I from experience going thru 3 certified MB techs know better .

Do not over look a posssibilty that is free to see . Any arcing , white stuff like everyone describes for caps/rotors. It was on one of my coils instead

400Eric · #42 03-28-2010, 03:23 AM

Quote:

Originally Posted by JohnM.

My 1995 540i with the 4.0L M60 is spec'd at 6.2 secs 0-60 (AUTO). The 1993 and 1994 540's were significantly slower for some reason. Mine gets 18-19mpg around town, with a lead foot, and about 24-25mpg highway. The 6 Speed 1995 540i with a Dinan chip is exactly as fast as the 500E, and would have no problem keeping up with an E34 M5. 5.5secs 0-60 for the 6spd. I've driven both....the 6-Speed is scary fast.

Well bring it out here son! Our next track day is a week from today Sat, April 03, 2010 in Fontana. We'll line 'em up! http://www.peachparts.com/shopforum/showthread.php?t=251933&page=7

I'll make you a deal: if you'll come out to our next track day, I'll give you that ECU for your M103!

This is my knappy 400E holeshotting a 97 540i 6spd: http://forums.turbobricks.com/showthread.php?t=193034&page=7 (Go down to post number 169, first and fourth pictures). In all fairness though he wasn't on top of his game yet cause it was in fact the track's first run of the day and the track was still cool and damp. (but he got much better later in the day, see next paragraph). He only ran a 17.73 on that first run. Still makes a nice picture though don't y'all think?

That 97 540i 6spd. got better as the day wore on. Here he is seen spanking a Camaro while running his best E/T of the day, a 14.908 at 97.33 MPH: http://www.youtube.com/watch?v=0og-7EoUJ20

My best E/T of that day, a 14.530 @ 97.22 with this car's best ever 60 foot of 2.297 despite the track still being cool and damp, was ironically the run against him. That E/T is even with me hitting the rev limiter! (of course nobody got a video of our run but thanks to one of my Volvo buds it is at least caught on film). My last run of the day was a 14.727 @ 97.57.

For the record, this is kind of a "slow" track, over 1000 foot elevation, a so so launching area, and the last half runs slightly uphill! Don't forget those times you see published are corrected to sea level and cool temps (60 F I believe). The 14.476 in my sig corrects to a 14.07 @ 101 MPH!

Bottom line: Benzes rule

Bimmers drool!

Back on topic now I would add to Peter's post that spark plug wires are another very overlooked part under the hood. Look for arcing there too.
Regards, Eric

PETERPNYC · #43 03-28-2010, 12:51 PM

Quote:

Originally Posted by 400Eric

I know somewhere in this thread there is info on the Euro 190 hp M103. I just can't remember which page. http://www.peachparts.com/shopforum/showthread.php?t=32224

Some info and links to videos and photos of actual 300E, 400E, 500E and 540i dragstrip experiences: http://www.500ecstasy.com/forums/showthread.php?t=6323&page=12

A video of my 400E running a 14.551: http://www.youtube.com/watch?v=sOpeNXP0sMw&feature=channel

The final word on the 540i vs. 400E/E420 debate: http://www.peachparts.com/shopforum/showthread.php?t=172171 The best info is near the end of the thread on the last page (but not right at the end).

Regards, Eric

Eric,
You really drive your car like that? I baby mine like a granny till I get to 70 MPH at least and then if I feel safe I will downshift it once to 110 MPH but only when I have good cop connections , and feel I can talk my way out of a speeding ticket.

Benz's drive like yours does? Coulda fooled me

tbomachines · #44 03-28-2010, 11:37 PM

Thanks guys!

I did replace the cap/rotor/wires already as tune up items. The coil still looked good and I haven't seen any arcing under the hood at all. Haven't made much progress since then, just another try at the fuel filter (no progress). I'll be driving it up to CT this coming weekend for registration/tags/etc. I have more tools and time up there so I will hopefully get to the bottom of it. All I have left for the initial tune up is the fuel filter and replacing the front brake rotors since the current ones are warped...have slotted ATEs waiting to be put on.

As far as power is concerned...I can't wait to get this thing up and running/tuned properly despite its inherent slowness. The engine is smooth as can be while running, can't wait to unleash it!! A T3/T4 turbo should do wonders

tbomachines · #45 04-02-2010, 03:17 PM

Update: Passed emissions today-- it did really well, way within the boundaries. Now, to make it run smoother and more powerful...pretty much going to take the entire day tomorrow to work on the car and polish it all up.