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

The PO307 has not reappeared. The car initially never made any knocking noise. Hard to tell exactly where the knocking is coming from. Which cylinder.

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

I replaced all of the spark plugs, cables and ignition coils. I think you might be right regarding the injectors. I went with a less expensive injector (still new) but I wouldn't be surprised that by being cheap I screwed myself.

I replaced all of the spark plugs, cables and ignition coils. I think you might be right regarding the injectors. I went with a less expensive injector (still new) but I wouldn't be surprised that by being cheap I screwed myself.

The tapping did not happen until I replaced the injectors. Question, do you think OEM Bosch parts would be as good as genuine Bosch parts?

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.

Jacob, when replacing the injectors, should I use a small amount of white grease on the o-rings of the injector?

What are your thoughts on remanufactured parts vs new?

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

The 2005 Mercedes CLK 500 uses 2 spark plugs per cylinder. The ignition coils have two spark plug connections, top and bottom. I currently have the top spark plug wire going to the front spark plug and the bottom spark plug wire going to the back plug for each cylinder. Is this correct?

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