WD40 or other moisture absorbing material.

This does sound like a wet wire, probably O2 sensor

my 2¢

www.benzbonz.biz

Marty

A wet wire has no effect on engine compression, nor the O2 sensor. Zero compression has to be be something mechanical. Electrics or electronics have nothing to do with compression.
I would have a major problem with someone telling me this, especially if he calls himself an expert.
No compression could caused by many other factors:
1) Have they removed the valve cover to check for a broken valve spring or a stucked lifter?
2) How have they ruled out a broken ring, or a hole in the piston, or even a cracked/broken engine block (very rare) or a cracked cyclinder head?
3) Have they performed a compressed air test to determine if the air pressure escapes to the oil pan or to the intake or exhaut manifold?

Hey angel! Don't let this dude baffle you with bull****!! You would get a second opinion from a doctor right? Doctors are just people and MB mechanics ain't God!!!


Smokie

You have been warned by many members of this forum trying to prevent another instance of someone being taken for a ride. If you just roll over and accept what this mechanic tells you without contesting, then you deserve the high $$$ bill you will undoubtedly receive when the dust settles.

It is true that none of us on this forum have inspected or even seen your car, so we don't know all the facts, but something just doesn't seem right. Obviously you thought so too, since you are asking for our opinions. I say trust your instincts.

By obtaining another professional opinion, you may save yourself thousands. Fear of confrontation and failure to speak up will cost you big time.

__________________
08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

I really appreciate all the advice- the mechanic called to say the valve was totally burnt and it would be around $3500 before tax. My head was okay. He took several pictures (I guess he thought he would need some proof). He said that it had nothing to do w/ the water. I am still so shocked how it happened immediately after washing the motor, but that there is no connection. Have a great day and thanks again. Angie

That IS interesting.

Usually a burned valve becomes evident more gradually, not abruptly like flipping a switch.

Thanks for the update.

__________________
2012 E350
2006 Callaway SC560

angel, i am finding difficult to understand as to why are you allowing yourself be held hostage by this dealership. call a tow truck and get you car into your place of liking.

__________________
joel

Prayers bring forth enlightenment.

Valves burn if they don’t close properly, not enough clearance.
If the engine start running rough it is really burnt.
As long as the valve seat is not damaged you only have to replace the valve and grind it in.
Of course you will have to know why the valve is burnt, they are no supposed to burn.
$ 3500,- seems very much for this repair. The price for an exhaust valve is $ 30,-, gasket $ 105,- and $ 35,- for the bolds. To remove and replace the head will take about 3 hours if you are not in a hurry and another hour for fitting and grinding in a new valve. I don’t know about labour cost is the US but is seems rather overpriced, even if they replace all the exhaust valves.