Spark Plug Horror! Look! - Page 5 - PeachParts Mercedes-Benz Forum

johnathan1 · #61 02-14-2008, 04:16 PM

I'm just curious, but have you replaced the dist. cap and rotor? You probably already have...but I would look into those if it were my car...

ps2cho · #62 02-15-2008, 02:37 PM

Quote:

Originally Posted by johnathan1

I'm just curious, but have you replaced the dist. cap and rotor? You probably already have...but I would look into those if it were my car...

Yes replaced both about a month ago. I have a new updated thread with everything inside of it. Its on the 1st page of the thread list.

lee polowczuk · #63 02-16-2008, 09:18 AM

it always seems that new motor mounts fix the "misfire" problem.

However, when I did my stem seals...i wound up with a miss, too..made no sense to me... someone on the thread suggested that i loosen up the individual lines on the fuel distributor to isolate which cylinder was misfiring.. i did that... i think it was 4... anyway... i changed wires from another of the cars ....no difference...

somehow from the time i did the stem seals to the time the job was done 5 hours later..a spark plug went bad....

3.32 at the dealer and the car was fine...

however, the stem seal job on the CE didn't resolve my oil situation... i did the same job on our 260e and it solved the oil situation

brewtoo · #64 06-25-2009, 01:26 PM

Quote:

Originally Posted by ps2cho

Also, on spark plug #4, I can hear ticking, or the spark...so we were thinking and it could have been possible that we mixed up one of the small little metal things on top of the valve's when we replaced the stem seals, because I know that we mixed them up (they looked identical so we just guessed it would be ok)

OK, It's been a long time since you asked the question but I didn't see the answer later in the thread. The part you are asking about is called a Ball Socket. I am very familiar with that part because a mechanic dropped one of those into my engine at some point in the past. For years it banged against the oil pump screen and eventually broke through, went into the oil pump and locked it up completely when it lodged between the gears. That caused the sprocket to rip off of the front of the oil pump. You can imagine.

Anyway, that's what it's called and they do not come in different sizes.

You never did say what was the cause of your misfire...

ps2cho · #65 06-25-2009, 03:37 PM

I still have not figured it out yet unfortunately. I made other threads that compiled everything here along with numerous other things I have done.

I have established that it has gotta have something to do with the idle fluctuations as soon as the engine gets into closed loop. The ICV keeps opening and closing as the vacuum gauge moves with the rpm's. So something in the ignition system is doing it. There are only a few culprits left -- Potentiometer (checked voltage on it and it showed fine), hall sensor and crank position sensor (checked resistance and was within spec).

I am going to start by swapping the entire CIS with the one from my 260E to see what happens. If anything changes then its gotta be the potentiometer as everything else I have swapped on that unit. Then swap the hall sensor from my 260E. My 260E drives great, so whatever I swap should show a difference if it is bad.

pawoSD · #66 06-26-2009, 12:51 AM

My 300E still slightly fouls the plugs after about 2,500 miles or so....but only a couple of them get any significant deposits (cylinders 5 and 6), I am guessing its because more oil pools above those valves due to the slant of the motor and the forces when accelerating etc....thus more gets sucked into those cylinders past the valve seals. I just pull those two plugs every few months and clean them off with a pick and some brake cleaner.

They don't get remotely as bad looking as the ones in the beginning of this thread though. Just the #6 plug accumulates a little bit of carbon between the electrode and tip....just enough to ground it out part of the time. The motor only uses a quart per 1100 miles or so. I'm saving my $$ to have the seals done (or, if I become daring enough) do them myself sometime in the future. For now I don't mind the occasional 10 minute spark plug cleaning. With my picks and some brake cleaner I can have a plug looking nearly new in a few minutes.

Switching from Mobil 1 0w40 synthetic to Shell Rotella 5w40 diesel synthetic made a huge difference/decrease in oil consumption and plug fouling.

optimusprime · #67 10-12-2016, 02:12 PM

Quote:

Originally Posted by Gilly

Best/easiest way to do the 103 valve stems seals is to use compressed air to hold the valves up, but there is a fairly specialized tool normally used to compress the springs. I imagine a little ingenuity would go a long ways to getting this done, any thing you could come up with to compress the springs with the head on. Might need a failry large tank compressor, although once the cylinder is pressurized it shouldn't take too much to keep it under pressure. There are ways to get around this that I'd heard of too, such as feeding rope into the cylinder with the piston down, the bringing the piston up until it won't turn any more, then removing the springs. Amything to keep from letting the valve drop into the chamber.
You are OK to drive it this way.
If your coolant leak is on the left (drivers) side rear, it may be an o-ring, the part that the heater hose attaches to has an o-ring around it and these often get brittle and crack and cause a coolant leak. Sometimes the leak follows the angle to the right and will drip off the right side of the rear of the block. Be sure of where the leak is from. Should take less time than Raymonds diesel.
Gilly

I like this .Your spot on ...This is just what i had go on my M103 after i changed the coolant pump. Small O ring on the heater pipe joint on the side of the head.And just like your post it runs off the rear of the head and then onto bell housing to the floor...I fitted new O ring , and sealer also for piece of mind.