timi2shoes

Hi everyone, was wondering if someone here can guide me in the right direction.

Was driving my 2007 C230 and all of a sudden CEL came on. When I got to a red light and slowed down CEL started blinking. Got the car home and checked the codes on it. Only code I got was P0300 "Random/Multiple Cylinder Misfire Detected".

I changed all the spark plugs, no change. Using an inline spark plug tester checked that all the spark plugs were getting a charge, they all were.

It seems like a very broad error, anyone have any thoughts?

indymerc

compression test/cylinder leakage test is the next step,common fault where the valves dont seat correctly.

271 engine??

timi2shoes

This is a M272 engine with 54,000 miles on it. Also on a side note I did notice that the oil was overfilled past the dip stick max line. Would that cause any of this??

I have not tried the compression test but will do that soon. I am hoping to troubleshoot easier things that might be causing this.

So far I have turned on the car and unplugged the MAF. The engine dropped its RPM a little but seemed to continue running as it was, no real change. I assume that means that the MAF is not the issue?

Any other suggestions before I do a compression test?

timi2shoes

So i finally caved in and went to a MB dealership. They ran a bunch of test and are telling me that cylinder one is losing compression. The dealership however wants to open up the head and do more tests. They have quoted me with further testing and possible repairs ranging from $4,000 to $6,000.

I personally think that is outrageous!

I am going to have to take the car home and try to fix myself. Does anyone here have any recommendations to what it could be and what I can do my self to further test and possibly fix?

phister

could be the coil packs or maybe a fuel issue.

timi2shoes

After I opened up the engine, took out the cylinder head i found out what it was. One of the exhaust valve spring in piston one had broken into three different pieces. Lucky all the pieces were still around the valve so they didnt travel anywhere. Problem found now unto putting everything back together. I am kicking my self for not seeing the broken spring before I removed the head. Would have saved my self a lot of time.

traceytransam

Good for you. Mercedes try to screw me out of $3000. Try to use a scare tactic on me about the camshaft Oilers. I bought them off the internet for 273.oo and it took 2 hours and 20 minutes to replace them. So why in the world would they charge 3 grand for that?.... anyway good for you man.

timi2shoes

Same exact reason I decided to do this myself. They quoted me anywhere from $4000 to $6400 to fix this issue, this quote came from them because they thought the intake manifold was broken and the head might have to be replaced.

Here is a photo of what was wrong