rough idle on 190E after engine cleaning

Hi Group!
My 190E 1,8 from 91 "was" running perfect with 160k miles on it UNTIL I decided to give it a nice body and engine cleaning.
The engine was cleaned with a high pressure lance. Now it idles rough,
almost like it was missing a cylinder. When letting it rev higher...I runs smoother...but not perfekt. After testing, I unscrewed sparkplug of cylinder No. 2 and it was all wet, worse then the other 3.
- distributor cap is dry and replaced by a new one - the distr. finger is new - all 5 wires and plugs are farely new - all 4 spark plugs were replaced - I checked all 4 plug wires and measured about 1300 ohm an each - air intake is clean and filter is clean
with all that replaced...it didn't get any better.
What can it be? Some electrikal Problem maybe, because of the water from cleaning or the hard impact with the water jet? This accured right after the engine wash, so no sign of malfunktioning before. Funny thing is, right after the cleaning, I drove a couple of miles, and it was fine...then after a while...it started malfuctioning.
Thanks for any help, since I don't know where to start. I hope it's just some kind of sensor, since this happended with the coolant sensor last time. After cleaning the engine, I had to replace the coolant sensor.
Alex PS not gonna clean it again :O) but it looks so nice now...like new!
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could easily be that the hi pressure water disturbed or even pierced on or more of the vacuum lines

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Considered the dirts as protective layer.. :) Check the spark plug well for flooding and HT leads as well
Keith E14 4NS

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all 5 wires and plugs are farely new _________________________________________ Be sure to check the plug wires.....just because they are "farely new" (fairly?) new doesn't mean they work properly, especially after the engine cleaning. Put the engine of a 'scope and see what is really happening.
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Hi Guys!
Thanks for all your thoughts! Since I ran out of ideas, I had a mercedes mechanic look into it. They found out, it's the head gasket. Jepp..although there are none ot the "known" indications, he stayed with that diagnosis. They tested everthing else. Ingnition is perfekt, like on a new car, he said. Electrical is all ok. Vacuum lines are good to. Good thing is, since the gasget blew so suddenly, the prognosis is good, and there is a good chance of not having any cracks in the head. I started removing the head yesterday and will keep you informed. I am still fumbling with those annoying rods that hold the guiding rails for the timing chain.... but hope to manage...
Car has 160k miles...should I do the timingchain and tensioner as well? All of that looks good, so what do you think?
Thanks! Wish me luck here, guys, this 190 looks so perfekt, it just has to get back on the road.
weeping, Alex

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ok..bad news...after 3 days of enormous work... took the head off, and discovered just the gasket beeing bad...head and motorblock surfaces seemed ok cleaned everything replaced every piece of faulty rubber hoses and everything needed for gasket change i changed the head gasket, and did good work, for what i can tell i put it all back together....checked everything...did everything by the book.. the engine started instantly...but no difference...still rough idle
even worse...a scratching noise added itself to the fault list :O(
i checked the chain tensioner...seems ok...what could that bee now? its not anything connected to the v-belt...took the belt off, but noise still there. loosened timingchain tensioner...noise persists... this noise had been there before...but not this loud... what could it be now? oil pump? haven't changed the oil yet...could have gotten some water in it, while changing the headgasket... sounds like something is not beeing lubricated as it should hmm...i dont want so loose this patient...
thanks for help... alex

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Hi Group!
Ok...1/2 good news. changes oil and filter now engine runs smooth, with no extra noises.
still...the rough idle presists...i am beginning to think, the "bad head gasget" wasn't it after all. i mean, the gasket didn't look to good after 160k miles, but was still funktional.
now, i am clueless, could it be an electrical problem after all? once the enigine gets going, at about 3500 rpm...power is there an it's driveable... below that rev range...there is less power an it sound like it's not igniting as it should...
i read somewhere, that someone had the exact symptoms on his 190e , an it was a broken wire somewhere in the main wireing harness..
i guess i now need help from you experienced mercedes guys again.
thanks... alex

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Check the vaccum hoses. See any disconnected.
Keith Beast E14 4NS Docklands

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