1998 2.8 Z3 Spark Plugs issues

I just changed my spark plugs from the stock NGK Platinum to the Bosch Platinums. I noticed that the car starts a little iratically, then after 5 seconds RPM smooths out. The Z3 is stored so i haven't taken it out for a spin. I have started the car for the pst three days and each day it starts the same way. A little irratically then smooths out. Has anyone else experienced this?
Thoughts?

Did you get your new plugs at the BMW dealer? I know there are some cheapo Bosch "platinums" you can get at the local Auto Mart that look the the BMW ones, but are much less expensive and will cause drivability issues. They will work fine in your Kia, but not in your BMW. I believe the "made for BMW" Bosch/NGKs have more platinum in them and are a much better plug. The econo-platinums are like 5 bucks each and the BMW versions are like 20 bucks a plug. As long as you get the correct plug (from the dealer) the Bosch and the NGK are interchangeable.

We had a spark plug discussion in another thread that included the issue of the $20 "BMW" Bosch platinum spark plugs vs. the $6 Bosch platinum spark plugs (e.g., Advance Auto Parts). Ron Stygar posted that Bosch told him that the two plugs are identical.

When I changed the original NGK spark plugs in my 2001 Z3 3.0 a few months ago at about 75,000 miles, I went with the $20 spark plugs from the dealer (which were Bosch). The original plugs looked fine and the car ran fine, but it just seemed time to change plugs. With the new plugs installed, the car started up and ran smoothly immediately, and has run fine ever since.

Here is the other thread. Your choice.

http://www.bimmerfest.com/forums/sho...ht=spark+plugs

Do you think you may have to reset your engine management computer so it can re-adapt to the new plugs?

Originally Posted by BeemerMikeTX

We had a spark plug discussion in another thread that included the issue of the $20 "BMW" Bosch platinum spark plugs vs. the $6 Bosch platinum spark plugs (e.g., Advance Auto Parts). Ron Stygar posted that Bosch told him that the two plugs are identical.

When I changed the original NGK spark plugs in my 2001 Z3 3.0 a few months ago at about 75,000 miles, I went with the $20 spark plugs from the dealer (which were Bosch)

I read the post and I guess I'm wrong. From whats written it looks like the BMW and Pep Boys plugs are the same. Just curious, armed with that knowledge, why did you go for the dealer part at the heightened cost?

Originally Posted by Swanicyouth

I read the post and I guess I'm wrong. From whats written it looks like the BMW and Pep Boys plugs are the same. Just curious, armed with that knowledge, why did you go for the dealer part at the heightened cost?

1. At the time I changed spark plugs, I did not have all of the knowledge contained in the thread. I had heard some opinions that the aftermarket Bosch plugs were not the same as the BMW-branded Bosch plugs, as well as some anecdotal evidence that the aftermarket Bosch plugs sometimes caused problems in some cars. So, for the less than $100 that would be saved on a component that appears to have at least a 10-year life, that $10/year just wasn't worth risking it. So far, the BMW-branded Bosch plugs run fine in my car.

2. Although I have no doubt that someone at Bosch told Ron that the $20 BMW-branded Bosch plug and the $6 aftermarket Bosch plug are exactly the same, I don't know who that person was and I have not seen any documentation from Bosch of this "exactly the same", so my opinion is that the two plugs MAY be exactly the same, or they may not be exactly the same (equivalent and identical are not the same thing). Given that uncertainty, I would probably make the same decision today to use the BMW-branded Bosch (or NGK) plugs from the dealer. Since I have already replaced my plugs, I probably won't have to worry about it again for another 10 years. When it is time to replace my spark plugs again, I'll check the current state of knowledge about BMW vs. aftermarket spark plugs.

#2 is a great point and I agree.

I have heard the same i spoke to a Bosch Tech rep, and the parts are the same. Oddly enough the Bosch just don't appear to be compatible. My stock plugs were the laser platinum NGK. so i will replace the Bosch with the new set of the NGK's. Question, has anyone bought any plugs from ebay, as their price point are significantly cheaper. Are they knock off or legit?

I bought my NGKs from O'Reilley. They had them in stock, the part numbers matched and cost about $6 each. I took in my original BMW NGKs and we took the part number off the OEM plug.

Originally Posted by DashingDaryl

I bought my NGKs from O'Reilley. They had them in stock, the part numbers matched and cost about $6 each. I took in my original BMW NGKs and we took the part number off the OEM plug.

If the number stamped into the metal part of the spark plug body is the same on the O'Reilly NGK as the BMW-branded NGK, then I think you can safely conclude it is the same plug. The problem with the Bosch plugs is that the Advance Auto Parts Bosch plug does NOT have the same number stamped into the plug as the BMW-branded Bosch plug. The two numbers have completely different formats. Hence, the uncertainty.

Thanks guys,

For your assistance. Living in Canada the cheapest price that i have found for the NGK plugs are 13$ each. So i ordered some for ebay. The part number on them matches that of the OEM NGK's. I have been changing plugs for 20 years and never run across this issue. Anyways fingers crossed that the NGK that i ordered from Ebay aren't knock offs.