Payson

Well I just wanted you to tell how is youre idling, please specify ur engine.

And lets discuss how can we improve idling, just expose your methods to make idle better. Have you heard about the Italian tune-up? to make general engine working smoother? It consists in running ure car high revs constanly during a long time...


My car is a 320E and seems that at idle the car vibrates a bit more ( u feel it in the wheel or frill, i just dont know the word) and sometime u feel a low hesitation when you´re sit, in ur but xD

Well thanks all

bamberger_1

rough idle won't go away with Italian tuning, it might only shorten the engine's life and then it will go away.
Rough idle has many, many reasons. Hard to track them down. The most common reasons are:
*leaking cold start valve
*defective fuel pump relay
*any broken vacuum lines
*bad sealing of the injector valves
*damaged ingnition coil
*bad (wrong) spark plugs and cables
*and additional air intake due to broken hoses, pipes, manifolds...
*Air mass sensor
*burnt fuse of the OVP-relay
*miss alignment of the air intake flap
*broken or grounded temperature sensors
*broken micro switches of the throttle assembly
*damaged idle controler
*or just age and milage

it is just a big search and by chance find the reason

Payson

Well i have heard that the italian tune-up does really work for idle,exhaust,accel and all that. Just take a look at this webpage: http://www.mercedesshop.com/shopforu...ad.php?t=46769

Remember this thread is to comment how is your car idle, how to improve it and to expose treatments u make in your motor to improve it general function and idle, home-made or cleaners.

hellah fresh

Yes i have the same problem and i cant put my finger on it. My car idles rough while at a complete stop. It seems like it wants to die but never does. Also whenever i start up me car it dies. Then i goto start it a 2nd time it starts. What is causing this? Fuel problem? Oh jsut the other day my car didnt want to turn over, until i got a jump start and charged my battery it works. Can someone please help me and reccomend what i should do.

Payson

Is idling a weak point in W124 series? it seems yes huh?
Any 500 owner give his opinion?¿

An engine known as having rough idling is the 300, do V8´s do the same?¿

neanderthal

all an "italian tuneup" will do is make the catalytic converter hotter, and more effective, meaning a better smog test result.

gone are the days when lots of low rpm driving would cause carbon build up that would be eliminated with an italian tuneup and result in better idling.

azednalcm

maybe it's your engine mounts? I have a 1992 400E and I replaced the engine mounts and I can't even tell that the engine is on when at a stop light.

Mario

nkpnkp

I replace engine mount on my E320 1995 rough idle problems gone.

PaulX608

The v8 in my 400E idles as if it were an electric motor. Of course it only has 78000 miles and had a full tune up at 60k. I would check the motor mounts as metioned above. They don't last forever and aren't terrible expensive, you'd be amazed at how much smoother it'll be after that.

Payson

Ill see if I can change engine mounts as you say, you think it really works?¿
What did the full tune-up consisted paul?¿

Please continue exposing how´s your car idling whoever wants to.
Perhaps can any body help me with this(hesitation problem post):https://mbworld.org/forums/e-class-w124/157815-hesitation-while-accelerating-aaa.html

Thanks

Bigdot

after the port and polish on the E500 it was fine, but the SL has its "burps"
mark

Payson

So first It wasnt smooth and you tuned it a bit and now is oK?
What is exactly a port and polish?? Im spanish and sometimes I get lost in specified words.

Thanks

crr1612

hey guys i tried the italian tune up idea. from what i feel now, im idling a bit more roughly, but also i feel like the car doesnt have to work as hard while im cruising, almost like i have a few more horses. its not dynoed to im goin by the seat-of-my-pants-ometer. anyone else get results like this?

Payson

So you tried out the italian tune up? you say you feel a bit more power, but no gain in idle? it isnt smoother or anything? It is supposed to improve it.

Im thinking about cruising at third gear during a long time to try italian tune up out.

crr1612

sounds about right. im hoping if i continue to do it, the idle problem will get better, rather than worse like it did. i wasnt doin it for a long time tho, maybe a mile or so in 3rd gear goin like 70....im gonna attempt to do it on the highway when i get a chance, see if i can blow some crap outta my headers

Payson

Italian tune up is supposed to be done with in 3/4 of the engine rpm. Per example a car with a max of 6000 rpm should have done the italian tune up from 4500 to up. If u cant do this in final gear, get it done in third or fourth at lower speed and higher revs.
Really what merc engines need to be done from time to time is a long journey (about 100 miles and better when more miles)in final gear at high speeds, close to 120 mph or 200 km/h. Because old engines tend to relax performance if they arent given a full gas in a long period of time, or if you usually drive at low rpm.

This explains the feeling you have that your car goes more relaxed now, when speeding up.

thanks to all, please can someone take a look to the hesitation problem post?¿
Payson

yhliem

There are a multitude of causes for rough idling. There's little point in looking for a definitive answer to why YOUR particular car is idling roughly as this sort of problem is impossible to troubleshoot and diagnose without having the car present.

The best you can hope for is for someone to list possible causes; as bamberger has done...except he missed bad O2 sensor. From there you have to take it upon yourself to investigate further and narrow the possibilities down.

hellah fresh

I jsut replaced me alternator and my car still idle rough like it wants to die. What is a common problem? Take it to the dealership to get tuned up?

triggerman

Just got back from having my motor mounts replaced by an independant. MAN! that fixed ALL hint of rough idle! I have to look at the tach to see if its running and watch that I don't grind the starter when starting it. I would say try this first, its what I should have done.

mgw_300e

Port = port matching - it means they take the manifolds off and make sure the holes in the head and the holes in the manifold are exactly the same size so that ther is no turbulence/better flow. It usually involves grinding some metal off.

Polishing means they smooth out the inside surfaces - again, better flow.

Someone correct me if I'm wrong.

hellah fresh

yep. Porting is to make the holes bigger, Polishing is to polish the and smooth it out. BUt man i dont think my motor mount is causing my car to idle rought because sometimes it sounds like it is missing and wants to die. Forget it i'll jsut take it to the Mercedes dealership and pay $115 to see whats really exactlly wrong with me car.

shadowgriffen

Hellah,

Have you checked your OVP? my car had a horrible Idle (like it wanted to die) before I checked the ovp fuse, once I changed it, the car ran like a bat outta hell and it idled smoothly and quietly.

PS/EDIT: I would STRONGLY suggest you change your battery everytime you replace the alternator, -Also check/replace your serpentine belt.

mtheumer

I had that "Breathing" sort of idling. I had to replace my water pump as it was dragging on the Serp belt.

crr1612

everytime you replace the alternator?!? how often are you supposed to repace the alternator? i thought you just waited until it died, which isnt very often. i think my interstate is starting to go though, its 5 or 6 years old and as of a few days ago, its not starting as usual

shadowgriffen

It should last as long (maybe even longer) than your battery.