Just changed the plugs in my E320. Car was running fine before tune-up. After changing the plugs the check engine light came on. I stalled 12 Bosch Platinum 4 plugs. I had regular bosch platinum in the car before tune-up. Any ideas what could be the problem?

 

How is the engine running. Is it knocking? Is it eractic? Does it lack power when accelerating? A helpful tool would be an OBD II reader. You can purchase one from your Auto Parts store at around 39 to 70 bucks. A nice reasonable one will cost about 80 to 100 bucks. I purchased one, and it has been a money saver.

You may want to check your plug wires, be sure that no moisture is inside the plug wire boots. Something as simple as that can cause your check engine light to come on. Also check knock sensor, and O2 sensor. But the OBD II reader will definitely tell you what the deal is. Good luck! Let us know what it was, and what you did to solve it.

 

Reader indicated cylinders 3 and 5 were misfiring. Do you have a diagram of the cylinder locations. Your help will be appreciated.

 

Strange. Couple of ideas.

Have you double checked all connections, especially to the coil packs are good?

Did you CAREFULLY prize off the plug lead aps or did you pull on the wire? If the latter you may have damaged the wire.

Alternatively you have inadvertently crossed over an A and B plug lead on a particular cylinder. Did you mark them before removing them?

Unlikely but poissible that one of the new plugs is bad.



Stuart

 

Strange. Couple of ideas.

Have you double checked all connections, especially to the coil packs are good?

Did you CAREFULLY prize off the plug lead aps or did you pull on the wire? If the latter you may have damaged the wire.

Alternatively you have inadvertently crossed over an A and B plug lead on a particular cylinder. Did you mark them before removing them?

Unlikely but poissible that one of the new plugs is bad.



Stuart

 

If I can determine the location of cylinders 3 and 5, my problem can be easily solved. Reading indicates these cylinders are misfiring.

 

Strange. Thought I replied yesterday!
When looking from the front of the car Cyl 1 is on the left with 2 and 3 behind as you move to the windshield. 4,5 and 6 are on the roght (drivers side in USA)
Upper coil packs go to Plug A which is the forward plug for each cylinder.
Cylinder No. and Plug locations are actually embossed on the cam covers (at least on my SLKL 320.
Stuart

 

Snanceki, the information you provided me was very helpful. I found the cylinder and corrected the problem. I had a faulty spark plug. Replaced the plug and the check engine light went out. Thank you.

 

Snanceki and BenzoDJ, my apology for mis-description. I was not clear in my description of what to check, nor did I use the proper nomenclature for what I attempted to describe. The coil pack is exactly what I should have said, so, excuse the brain-fart! The exact same thing happened to me. What was strange when it happened to me was that I had just changed the spark plugs a couple of days prior to the misfire. Sleepwalker suggest to me what to do. Consequently, I checked all of the coil packs and plugs. The plugs were fine, which I suspected they would be. One of the coil packs however, had moisture down inside the rubber boot on the end that connected to and down inside the coil pack. So, I took a cutip and swabbed out the moisture real good and put a thin layer of di-electric grease down in there and on top of spark plug connected everything put it back together, crank the car, and it was fine as new wine. Since that worked, I just did the same thing with all of the rest of the coil packs and spark plugs. That seemed have cured my ailment in that area. Maybe that was a bit accessive, I don't know, but it sure isn't hurting. But again, I do apologize if I've caused some confusion.

 

One of the new Bosch Platinum 4's?

Saw some of these plugs today. I'll be interested to here how you get on with them rspecially after your poor initial experience.
I would personally stick with OE single point Platinums by Beru. Maybe they also use other makes for OE. Both my engines M112 (3.2 V6) are Beru however. 60K+ and they looked as new with no noticeable wear or rounding of the electrode when i changed them.

Stuart