fredkrhye

2005 C230
I washed the engine compartment and hosed it down with the engine running on Friday afternoon. Let the engine run for 5 mins or so and then shut it off. Didn't drive the car until this am going to work, got 5 miles away and the check engine light came on and it started running rough.

Any ideas of what went wrong? I would think that all the water dried over the weekend, hot in Texas and in the garage.

I'll check the saprk plug wires and everything else I can find, but would appreciate some help from you guys, maybe someone has experienced this same incident.
Thanks,
Fred

ncmudbug

It sounds like it might be that water may have collected around some ignition components - the same problem people had when in the past, their distributors got wet, things that were insulators were now conductors for high ignition voltage.

I would check for water around the coil packs. Dry it off and if that's the problem, it should be fine (unless the computer was trying to compensate and is confused or it's really something else).

fredkrhye

Thanks, I'll give it a whirl!

LILBENZ230

You washed the engine.. with a hose? On a W203?

Words cannot express what I felt at the moment I read that... and if they could, I'd certainly be banned for them.

fredkrhye

LILBENZ,
I just bought this car and the engine compartment was filthy! Did I just open a great big box of worms? Please clarify your comment.
Thanks,
Fred

LILBENZ230

I know how you feel about a dirty engine compartment.. Mine is much dirtier than I would like. That being said, we've had members on here that have had water contamination cause ESP module failure and front SAM module failure (both expensive repairs) and they hadn't washed the engine at all. Washing the engine compartment is a big NO on these cars and I'd think on pretty much all modern cars.

But what's done is done. Hopefully you took the time to cover things as best you could and things will be fine. But the idea of it just made me cringe. You should only wipe down the engine, water should never be under the hood under any circumstances.

sammydragon3

check the code first with a scanner at autozone..

fredkrhye

All,
The #1 plug well was totally full of water! Dried out the spark plug boot, sucked the water out and installed fresh plugs in all four. Runs like a charm. Sincere thanks to those who responded to help.
Fred

fiteallison

I would check for water around the coil packs

ncmudbug

Good point about the potential problem with those electronic modules. I hadn't thought of that!

Glyn M Ruck

I have posted a number of times on this issue. Washing engines is banned by MBSA at dealers. Over time you develop corrosion in all the connectors on the harness that can cause a mountain of problems. To say the least of Matt’s good examples.

Wipe down with a non silicone containing spray is the preferred method.

If you must wash the engine then you need to prepare it by covering & taping up all major electronics with plastic bags or similar. Then not apply high water pressure.

ncmudbug

Thanks, Glyn. I was wondering how to clean in the engine compartment. One thing I do like is the plastic panels under the engine that keep it cleaner than most cars!

Glyn M Ruck

Yes ~ I was surprised how clean we were able to keep the C240 over 8 years. Dealer did prescribed wipe down at every service with some genuine benz cleaner/aerosol & it looked almost new at sale. I of course don't have snow covered gritted roads to contend with.