george559

Im having some trouble with my car and the engine sounds like it's mis-firing. The engine shakes from time to time usually at the stop light and then has this crazy surge of rumbling from the engine here and there. The car drives like normal but shakes at stop lights

The spark plugs were foul when i took them out for a change, can this be the cause of mis-fire, causing the coil pack to go bad?

george-

sanf

yes...the dealer will say that's what's causing your engine to royal rumble nonstop

C230SportsCoupe

If your spark plugs are fouled then the car is probably running rich is an indication that the MAF requires cleaning or replacing, or your air filter is very dirty.

george559

the spark plugs are changed, and the air filter is still good. but the maf wouldnt cause the engine to sound like a mis fire and vibration.

SeaCoupe

Okay, so you come to the board, someone gives you good input and you summarily dismiss it?

Uhhh okay.

You'll likely dismiss my thoughts too so I'll let you handle this on your own.


E

george559

dude no one's here for any dis respect or dissmissive responses im just stating the facts and eliminating whats there to find out what it can be. There has only been 2 responses, i wont count your's since all you can do is take things the wrong way, im just trying to find the problem with the car and your not helping.

________________________________

-the plugs have been changed NGK Iridium for F/I Mercedes Benz
-the filter checked out to be okay, no build up or discoloration.
-sprayed the maf with Sensor Safe cleaning solution spray.
-checked the bottom of every coil pack to make sure the spring inside is still intact.
-and all the coil packs doesnt have tears or rips on boots or white calcium buildup from grounding out.

the engine vibrates like the mount is broken ( but is not ) and has surges periodically after 3x1thousands.

im taking it to the dealer tomorrow morning but if anyone had this symptom or know of any other way to fix it.

I would appreciate it.

george-

SeaCoupe

Look man, this is stuff I TRULY like to do. What I was mentioning was that there is some checking of the AF that could be done. Does the car run fine with the MAF unplugged? If your problem goes away, suspect that MAF.

However my first input would be, what are the OBD II codes, if any? Get the car read, then you can get some ideas.

I'm going offline for the rest of the day, however, I'll check back first thing tomorrow a.m. to check in on your codes.

Zeppelin

Put the air duct back to stock and take the car to a dealer for Warranty Repair.

advans

thats what I was gonna respond with E, I was gonna say unplug the MAF. see how it runs.

c230Pilot

put it back to stock and see how it is. Your intake temps could just be way too high at stops causing fuel problems. I assume its pretty hot down there right now. I definitely would make it stock before bringing it in. No dealerr "voids" a warranty, but they will say the aftermarket part caused the problem and won't fix it under warranty.

george559

Dang another try and nothing. I started the car unplugged and started the car with it plugged and then unplugged it. NOTHING.

oh yea, THANKS ALOT FOR ALL THE FEED BACK i appreciate it greatly and will be a member of this forum for a while and ill do my best to help others while i learn as i go.

I also bought a new air duct (52 bucks ) and popped it in. Still nothing.

I was thinking, when the spark plugs went foul and not spark correctly can it make the coil pack go bad too?

thanks again

george-

SeaCoupe

Okay, so you ran the car with the MAF unplugged, and have the same prob. We have eliminated the MAF. Next up is your injector cycle. Does this happen at cold idle or only at a warm idle.

run the car, give it about 5-7 minutes of running. Spray water on each of the exhaust outputs. If everyone of them boils the same, you can eliminate injector pulses.

I really think that you have an O2 sensor problem at low temp. It is the opposite of an 02 sensor failing at high temp. you have a problem with (likely the first sensor) failing at low temps. It is reading too high 02, and goosing the injector pulses. Thus the fouling.

W/O OBD codes that is the best I can do.

Hey, I logged in just to check on you. Hope you appreciate it.

advans

hmm

E, Do you know of a good OBDII reader?? for our cars atleast...I need to get one!

SeaCoupe

I came back just to check on the guy, but no update. I use one with memory. That allows me to download data.

I have it at home and will take a look for you. Right now I'm at work and don't have it here. I think I paid about $200 bucks for mine. If I could do it over again, I would get something that ran through my laptop so I could have more data logging capability and real time monitor stats.



E

george559

Thanks a grip for checking back with me, after a crazy morning @ the dealership. and a 110 dollar diagnostic fee.

We have a broken hose from the manifold to the super charger built up with carbon and a brass looking fitting.

500 labor cost to replace the hose, which costs 34 bucks.

dang this whole time i thought it was an ignition or sensor problem, but a hose.

thanks again Emrl. for all the help I DO APPRECIATE IT THOUGH i couldnt sleep pondering over this problem. You've been more then helpful and hopefully i can use your brain the next time something goes wrong.

You should've see the repair sheet for the warranty.. 4 pages of evap. valve, sticky exhaust valve, a/c evap, alternator, camshaft, etc.

oh yea, thanks for everyone's input too.

george-

SeaCoupe

WHOA!!!!! This is unreal. I'm familiar with ALL of the hoses leading to and from the supercharger and the plenum unit that is above it. Do you have a part number for the hose that they replaced. I truly don't want to see that they screwed you on this. While there is intake ducting going into the S/C, the hoses are two fold. One that goes from the top of the engine cover to the black plenum intake, and one that is long and thin, and plugs into this same hose.

There is a oil catch hose that goes from the back of the plenum to the oil pan, but I doubt it would be this.

Let us know if you want. May save you some money.

E

C230 Sport Coup

Sounds like issues from using an oil soaked aftermarket filter?
I used to have an ITG but I had problems with things sticking, clogging etc. and went back to stock.
Hey E, what was the solution to your problem, when we were at the show the low power issue?

Whatever hose he needs I'm sure he could do it himself for a lot less than 500. People think I like working on cars. Not true.
I HATE working on cars.

But I hate throwing truckloads of money away for simple repairs even worse.
Like thousand dollar alternator repairs that should cost about $250...bah! OK, sorry, don't mean to hijack the thread.
Did he say he got it all done under warranty?

SeaCoupe

I had put a thread up. On my cold start up, the air check valve stuck. While I got the Xenons set to present, the DAS operator also did a cold start check, and everything was fine.

What a waste that you and I didn't get to run agains each other that day.

E

george559

there was some hose under the airbos between the intake manifold and it was the PCV hose. It had some wear and tear or even a little pressure and busted right off. i bought the hose (which i shouldve got the steel braided one if this happened) and some intake manifold gaskets.

im going to return those monday and their $2.14 clamp.

the tube went to a brass fitting that was a PCV valve, and just like taking off a vacuum hose it made the engine shake and even cause it to misfire.

I SHOULDVE KNOWN it happend to my beamer. European cars tend to this huh?

dang, what a repair it was easier then changing your oil.

2 bolts in the back, the Air box clamp in the back down below and unplug all the sensors. Jimmy it back and pull it up and you can see the hose on the bottom left near the manifold.

thanks alot yall for all the help.