crr1612

for the past few months or so, every once in a while as i hit the accelerator on my 1991 300ce, the car would accelerate very unevenly, almost like i was hitting the accelerator and taking my foot off and hitting it again, very quickly. then today, i pulled out of my parking spot in reverse, stopped, put the car in drive and hit the gas........and my car didnt move. the rpms didnt even go up. so i check to see if im in neutral, which im not and then turn off the car and start it again. it worked the second time but i still had very jerky acceleration. anyone know what my problem could be?

crr1612

i forgot to mention, my mpg's have dropped from around 300 to closer to 230 when the accleration got worse

ashman

a few things to check... Search OVP, oxygen sensor, and fuel pumps

crr1612

i just had my oxygen sensor replaced, and i believe my fuel pump is fine. what is the ovp and how do i check it?

neanderthal

start with the most basic things;
check and replace fuel filter
oil and filter
spark plugs
wires
cap
rotor

make sure you are getting a spark and fuel at the cylinders, then OVP and all that other stuff ashman mentioned.

crr1612

all of these are checked or new. any other ideas? i just added some oil additive, gas additive, and even threw some sea foam into the throttle body, but to no avail.

ebennz

neanderthal wisely suggested you start with the most basic things;
check and replace fuel filter
oil and filter
spark plugs
wires
cap
rotor


when EXACTLY did you replace your FUEL FILTER, spark plugs, plug wires, fuel filter, cap, rotor?
what about the main engine wiring harness?

replacing this stuff is expensive-that's why most people don't do their required maint.
neglect of this stuff will really bite you.

how long have YOU owned the car?

don't know how your car would sputter around if these things were done...it doesn't make sense.

these suggestions are from several long term m.b. owners, neanderthal, ashman, myself.

crr1612

they were all replaced when i got the car, around 2 years ago. i did not replace the main wiring harness, could this be the cause?

black320

Well, first you have checked these main stuff and they look ok, right. Check the adjustment of the battery. If its ok
I guess u have to check the wiring harness as it might be the problem. but u have to make sure that it's the problem as it's expensive.

crr1612

the battery is pretty new. how would i go about checking my harness?

black320

have u adjusted the battery as there is a place for using the screw, it balances the power. regarding the harness I guess you have 2 check it through the w124 computer in a MB garage.

crr1612

ugh, ill go to my mechanic...ALL RIGHT, $80 AN HOUR FOR "LABOR"! ill make an appointment and keep you guys informed as to what happens

crr1612

good news guys. i went to pep boys and bought a bunch of crap for my car. fuel tank de-water-er(?), fuel injector cleaner, oil additive, and some sea foam. i put it all in where it is supposed to go and cleaned out my throttle body with the sea foam. incidentally sea foam makes for a nice show. anyway, it still ran crappy for the tank, with hesitation and jerky acceleration. then i ran out the tank of gas and put filled it with some 93 octane, i drove it home for aorund 80 miles or so highway and didnt notice a difference. then i drove it again for the first time since and i noticed a huge difference. i knew something was up when i turned the key and the car started immediately, i didnt have to give it gas or hold the key in for more than a half second(usually i have to give it gas and hold the starter for 3 seconds). i was in disbelief, so i turned the car off and turned it back on again just to see it happen again. then, i started the car and put it in drive, still slow as usual between gears, but i hit the gas and the car took off nicely, with no hesitation or stuttering. so i ran it through the gears, worked the kickdown, and it runs beautifully. so, if anyone else has that problem, whatever i did worked. now only if i didnt have to wait so long in between gears, the kickdown takes a few seconds before i change gears

shadowgriffen

haha! Nice, I wish I was half as stubborn as you are my friend!

I need to do all of this, I'm having similar symptoms (save for the acceleration part)

crr1612

make sure you arent gonna be doin anything important with teh car a short time after you do this. you have to run out the whole tank after putting in the chemicals, or atleast i had to. also, when you put the sea foam in your throttle body, a very thick cloud of smoke will come out for a little while...so make sure your not goin out to pick up a date and have white smoke comin out of your exhaust. but other than that, good luck with it. its only $30 or so for chemicals, and thats at a pep boys. its probably more like $15 or so at a walmart.

crr1612

i was thinking about my transmission toubles and thought about another sea foam product. has any tried out the sea foam trans-tune? my major problem is that the car is taknig so long in between gears, when i shift from reverse to drive it takes a few seconds. i figured since the sea foam worked so well teh first time, i may as well try another product like it in the transmission. any other ideas?

crr1612

also, i just read this on the sea foam site

When erratic shifting, rough shifting or slow shifting occurs in the automatic transmission – this is often caused by contamination if changing the fluid and filter is not done on a regular basis. Dirty fluid or gum and varnish buildup can also cause these problems.

Your service technician can offer a SEA FOAM TRANS TUNE treatment and a fluid and filter change or a transmission flush to restore smooth and proper performance providing there are no mechanical problems.

crr1612

and read this on consumerguide.com about the 300ce transmission. its seems like what i have

Automatic transmission: The transmission may delay shifting into Drive or Reverse, and may be corrected by installing reformulated Mercedes-Benz transmission fluid.

crr1612

bad news, the car resorted back to its old ways...ugh

Remonster

Sounds like you need some new trans fluid plain 'n simple, I have a '91 300E and it also has problems with gear shifts but its basically when you turn on the car for the first time when it has been off for more then 10 hours or so and you drive it normally (not hard acceleration or anything) the 1-2-3 gear shifts take quite a while, infact in the same area where the car can handle about 35MPH in 2nd gear at like 2500 RPM, it will rev up to 4500 before it up shifts during this first minute or so of being on, its kinda weird and my dad refuses to change the trans fluid which I think may be the problem (im afraid this is the beginning and its gonna slowly degrade until its like yours ) I mean the car has 199,600 miles on it (drove to In n Out today and was like OMG almost 200,00!) so I'd be surprised if something DIDNT happen to the trans by now

EDIT/// I should probably say that Im 15 and not a car mechanic by any means so I am probably wrong lawl.

crr1612

my fluids been changed recently, i may try to get it flushed soon. i dont think its the transmission though, but well see. the car stalled out on me 3 times yesterday, the hesitation is getting unsafe, from around 1500-3000 rpm i can feel the eninge is missing, and the acceleration is extremely unstable.

crr1612

i noticed that the symptoms go away once i fill my tank. then the car runs fine for a half tank, the the symptoms slowly come back to where they are worst as the tanks runs out. fuel pump problem? water in my tank? any ideas?

Makahveli

My car is having these issues now, it hestiates when accelerating, about 2 weeks ago I put that BG44k in the tank and it was last seafoamed back in I'll say october. I don't know if I can be mad at the tranny cause the RPM's aren't going crazy like it did in another car I have.

Bigpete123

'tis the struggle of every w124 owner...

diablo roadster

nice post count