alexus

Hey all
I realized that some times my C280 '97 Sport drops its power tremenuosly. Ex when i stop at the lights and start movinbg again i have to step on the gas like 50% down to get 40mph by the middle of the block (high way road block say 900ft in total ~~) At the same time on the same road when i feel that car has power i can press gas ~10-15% down and get to 40mph in about 1/4 of the block. Also what I notices is when I dont press on gass and i'm going los speed say 20mph I feel like cars brakes are in use and i'm loosing seed too fast.

Maybe some one have any ideas? Car has 83k miles on it so it seams not too much for mercedes. Oh yea, if I go max speed and max throttle for new sec (say from ligh to light) and then geting back to normal driving it seams that car gets much more power aftter wards. hmmm

Another note.. when car is not moving and engine is idle i get sort of vibration es[pessially when there is an decline toward passanger side. but when i release the brake and start moving the vibration goes to relative zero.

Finally I took OBD mesurments (maybe they would be handy for experts)
I hve results in both parked and driving positions of transmission (in both cases car was standing still) below is my data:

I hope some one can tell me what it looks like. Maybe i'm just being paranoid ...
Thanks for help!

Untertürkheim

It seems strange that there would be so much load on the engine, is that normal?

alexus

I cant say anything about load I dont remember old OBD2 readings... so maybe some one with share their load values on idle?

My new mech told me to use differenet oil 10W-30 instead of 10W-40 that MB reccomends. can that be a problem?

Untertürkheim

Do not use 10w-30! Get a good 229.5 -40 weight oil like Valvoline Synpowr 5w-40, M1 0w-40 or Liquimoly 5w-40.

Is the engine reving with low power, or are the RPMs staying low?

alexus

RPMs are fine (i think so at least) Tach goe to 20k then switches gears... same as in old days.

Just feels like i'm haveing 400 pounds in the trunk. Thing is tha its not the same, some times it works like i have 300 hp instead of my 145 hmm

Another thing is that engone wireing harnes that goes to (what thioese things called in English .. the once that prodie sparks for ignition) one of the wires seams to be either cut off and replaced (hopefully) or just cut off i think it should be relaced as OBD doesnt give any warnings so i assume all cylinders are fired up OK. I will have pix of that wire posted.

Whats a difference in oils
which part of oil means what. I know one is wiscosity and another um forgot.

How do i select oil? I dont want to "liquid" oil as it will leak. I have drain plug leakage .. i think all merces have that.

rondocap

I have a 2000 c280 sport with 90k miles...I notice this too. Sometimes it isn't as responsive on the throttle and acceleration, but other times it's really much faster. I always use 93 octane gas, and Mobil 5w40.

I don't know what it is, maybe the engine on these cars is just like that and not always consistent?

alexus

so i guess its not only me
I will be stopping by Mercedes performance shop that does sports cars and tuning, I'll see what that would say.

rondocap

Yeah, let us know what they say - I want to know too. If it is something serious, we can fix it.

alexus

everything is fixabe the question is how much =)

C43AMG

When is the last time the plugs,fuel filter and air filter were changed?Start with the basics for you start throwing money at theories.I would also look at changing the mass air sensor.

alexus

All filers were changed last september when i had B-Service at the daler (or at least they claim so) plugs where not touched in last 2 years, and before that it did not own the car

C43AMG

Then , beased upon your mileage, the plugs are due.I would change them and then look at the mass air sensor.

alexus

which plugs are better for reasonable price?

I can see bosch platinum plugs goes from $2 to $50 per each peace, but what is the difference? paying 50 x 6 = 300 for plugs alone is a bit too much for me on another hand 2x6=12 makes me cautious for low price

mass air sensor - where it is located?

AcousticplayerJ

Check for leaks. I had an issue like that last summer. My car would barely be able to push 30 MPH without using all the gas. It turns out that some oil was leaking into one of the air-intake filters and essentially starving the engine of air. The dealer figured it out and fixed it. Afterwards, the car ran like new. Keep in mind that cars can slow down as they age. Though, what you're describing is very unusual.

alexus

well i went to a performance shop
they changed fuel pamp and spark plugs + filteres....
now it runs steady, but I think at the same time it runs steady as it has less power now hmm but is hard to say now i need more objective way of mesuring power...

I guess i will go to airstrip and do 0-60 test... i hope police wont see me there...

AcousticplayerJ

I recommend taking your car for like a 30 mile trip or so on the highway. My car always runs better after some good highway driving. If you can, take it up to about 60, then gun it up to 80 or so. Push the car a little bit (but not before it warms up!). That should help prime everything a little better. I would say that if you don't notice anything after like 150 miles, have them check it out again. By the way, does your car have a supercharger? If so, those add a bit of power, but take a second or so to kick in. So initial acceleration won't be so great, but then the car will fly.
P.S. just watch out for cops if you're going to go past the speed limit. They hide everywhere!

alexus

well afetr reak good worm up car goes pefect... drove it at 80mph...
but nost of the time i goe 20mpg in the city like and thats like terribel but at the same time i dont gas to much in the city line... no point geting fast and then wasting the brakes in 1 min on the nex light

PS: unfortunatly dont have supercharger... i'm not sure if i can get one in good condition for W202

AcousticplayerJ

Glad to hear it's working well. My car takes a few min to warm up before it's good too. But after the initial warm up, all is great!