1997 C280 rough idle after wash

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1997 C280 rough idle after wash

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1997 C280 rough idle after wash - 10/28/2005 10:13:37 PM

Mywifescar

Posts: 48
Joined: 10/28/2005
Status: offline

My wife had to have this car and I have to admit it is a cherry, I don't think it ever came out of the garage it was in when we got it. Exterior mint, interior mint, even has that new car smell. Under the hood was dusty and had a smell of oil couldn't see any leaks but it was dirty. I got some engine degreaser and washed it off .... now there is a miss or the idle fell to low (around 5-6 on the tack) at 10 it is smooth but at a stop it started to stumble. I took off the air crossover and cover where I found 3 coils and 3 sparkplugs top end full of water. So I used my shop vac and a straw to empty the water. I got a set of OEM plugs and wires. When I changed them I noticed that two of the plug wires were cut by a metal plate between #1 + #2 spark plugs. Thought new plugs and wires would do the trick but just my luck still stumbles and the check engine light is shining brighter then ever. I disconnected the battery for about 15 minutes and when I restarted the car wow at idle beautiful .... no light no stumble .... so I punched it and it had great response but ... POW on comes the light and stumbling is back to vibrating.... Other then new coils I made sure everything was dry. Now to the question what under the hood would cause this problem by just getting wet ? The MB dealer wants $250.00 to hook it up to their computer so I sent away for a obd2 reader that has code reset options and should fit the plug under the dash. Just thought I would ask if anyone had this problem or if you know how to read the codes without the machine (like with the old gm's jump two pins and it starts to blink the codes)

Post #: 1

RE: 1997 C280 rough idle after wash - 10/28/2005 10:27:06 PM

Kajtek1

Posts: 772
Joined: 9/29/2004
From: Bay Area CA
Status: offline

AutoZone is leasing readers for free.
The $220 dealers want for code reading will buy you 2 readers with reset buttons at JCW.com
Welcome to the forum.

< Message edited by Kajtek1 -- 10/28/2005 10:28:40 PM >

(in reply to Mywifescar)

Post #: 2

RE: 1997 C280 rough idle after wash - 10/28/2005 11:12:12 PM

sleepwalker

Posts: 7080
Joined: 4/12/2004
From: Philippine Islands
Status: offline

quote:

two of the plug wires were cut by a metal plate between #1 + #2 spark plugs

this must have cause it

(in reply to Mywifescar)

Post #: 3

RE: 1997 C280 rough idle after wash - 10/29/2005 9:45:49 AM

Mywifescar

Posts: 48
Joined: 10/28/2005
Status: offline

The plate seems to belong there I tried to pull it out but couldn't ..So I covered it with a small piece of vacuum line ... When I replaced the plugs+ wires it still came back .... I gave the coils a close visual inspection and didn't see anything wrong although they are made by different manufactures two are the same with flat topes and one (center) has round top ??? Does anyone know how to test a coil with out any pain ...

(in reply to sleepwalker)

Post #: 4

RE: 1997 C280 rough idle after wash - 10/29/2005 9:55:05 AM

Mywifescar

Posts: 48
Joined: 10/28/2005
Status: offline

AutoZone is leasing readers for free ????

I called AutoZone and they thought I was nuts they wanted to sell me this little orange reader for over 100. Or they could have someone from there shop check it out (for a fee) here in my section of NJ. nobody speaks English until pay day and I don't want any of them Yanking wires to see what's wrong.... but thanks for the info

(in reply to Kajtek1)

Post #: 5

RE: 1997 C280 rough idle after wash - 11/1/2005 10:33:44 PM

Mywifescar

Posts: 48
Joined: 10/28/2005
Status: offline

Well I will make it short and sweet. I got a Equus 3030 code scanner and ran thru the tests found #2 cyl not firing . Found a place online got a 3 pack of oem coils installed in about 8 minutes. What an easy car to work on I can't see how they charge so much at a dealer. after putting the car back together I reset the code and fired it up WOW smooth you could put a glass of eater on the top of the motor and not see a ripple in the water
Idle dropped to around 6 on the tack . So I crossed my fingers and punched it WOW again. I don't like to drive my wife's car (because I get blamed for every bird $%$# on it) but I had to take it for a ride. So I took it out on RT 3 here in NJ and before I knew it I was doing 120 and had plenty of peddle left GREAT RESPONCE AND HANDELING now I know why she wanted it. so the total for my Fu%^ up $60.00 plugs and wires $70 for the code reader $150 for 3 coils my free tine total $280 The closest dealer wanted $250 just to hook it to their computer $190 for 1 coil $145 for wires and $8.00 for each plug all in all today was a good day
Hope you all have the same luck and good fortune

(in reply to Mywifescar)

Post #: 6

RE: 1997 C280 rough idle after wash - 4/27/2008 9:15:24 PM

Bdaddy7020

Posts: 1
Joined: 4/27/2008
Status: offline

I am curious to how many people have read this thread. I also washed off my c280 engine and after ward it also began to begin miss. I usually do some of my own work but have been a bit intimdated to jump into the world of German auto technology

. However at this point I knew the problem to be in the secondary ignition, (from coil to spark plugs for those of you wondering ). Well sure enough I found a couple of things: first the reason water was able to breach the ignition cover was a couple of stripped allen screws and the culprit was water in the #6 spark plug hole. All is well and running great. This almost three year old post saved me a bundle!!!!!

(in reply to Mywifescar)

Post #: 7

RE: 1997 C280 rough idle after wash - 8/25/2008 6:40:42 PM

WaBenzer

Posts: 3
Joined: 8/25/2008
Status: offline

Mine''s a 1995 c280 with 130,000 miles in So. California. Bought it 3 months ago, and it is very smooth... until today getting off the freeway. It started missing like a plug wire fell off. Autozoned and Kracken want to sell me a scanner and the gals at the aftermarket shop want to charge me for plugging in their scammer.

It has always stumbled at 1/3 to 3/4 throttle, like my wife.

No fluid leaks and oil/coolant are clean and good looking, unlike my wife.

Should I pull the plugs?

Thanks

79 300d
84 380se
95 e420
yay!

(in reply to Mywifescar)

Post #: 8

RE: 1997 C280 rough idle after wash - 8/25/2008 10:17:58 PM

lwbrewer

Posts: 123
Joined: 2/17/2008
Status: offline

I like to have the motor running when I wash one, and take my time. So when I hit a spot with the hose, and it starts to miss I have a better idea where to start. Also WD-40 works great spray it over the electrical parts and it will remove the moisture. I''ve seen where a car would not start from washing the motor a quick spray of WD-40 had it running with no wire pulling.

87 300D

(in reply to WaBenzer)

Post #: 9