Engine Misfire #7?

Hi,

Is it possible for you to record the noise and upload it for me to hear? Also, although there is a noise, does the misfire still exist? Was the P0307 misfire code the only one you found?
Does the noise seem to come from cylinder 7?

Take a look through this link and let me know if you feel anything mirrors what you hear:

https://www.2carpros.com/articles/engine-noises

Let me know.

Joe

Hi,

If the code hasn't returned, then it appears the misfire has been resolved. Now for the noise. Is the knocking loudest at the top, side, or bottom of the engine? Is there a way you could record it and upload it for me to hear?

The idea this started with the injector replacement makes me question if the correct injector was provided to you. Also, were all spark plugs replaced, or on the cylinder 7 spark plug?

Let me know.

Joe

Hi,

Yep, I meant the injectors. LOL Bosch is the OEM part so I'm not sure I understand your question. Did you use an aftermarket part?

I attached the OEM part number below. Let me know if that is what was used.

Take care,

Joe

See pic below.

Hi,

As far as remanufactured parts, I base that on a few things. The first is the cost difference. Second, how difficult is it to remove and install a new part of the reman fails or is faulty? And finally, how much use the vehicle will get, and does the customer plan to keep it for an extended period?

Also, because this is a Mercedes, they can be very sensitive to differences. People often look for the least expensive part online. Many of the inexpensive online parts simply don't work. If you purchase one from a parts store, at least you have a better chance of getting a good one.

As far as the O-rings, yes, they should be lubricated before installation to prevent damage. Don't laugh, but I use Vaseline on injector O-rings. It works great.

Just FYI, anytime you are replacing O-rings, regardless of their purpose or application, you should lubricate them.

Let me know.

Joe

Hi,

Although each coil has two spark plugs, both are for the same cylinder and fire at the same time. What you described does sound correct.

When you replace the spark plugs, it's a good idea to lubricate the spark plug boot with dielectric grease. This helps eliminate the possibility of moisture and helps maintain a good connection.

Let me know.

Joe