I want to upgrade my stock coil , wires and plugs on my 2008 MCs cabrio.

What is the best option for these?

No pulley install as of yet and not sure when and if im gonna do one.

Thx mike

 

Coil: Don't bother the factory coil works as good or better than the aftermarkets & will generally last longer also. (190,000 miles on mine)
Wires: Again not much difference, just don't buy cheap ones. (I switch from my good wires to my OEM's all the time doing diagnosis of electrical issues, miss-fires & such, don't really notice a difference)
Plugs: Still stock, No pulley=NGK BKR6EIX
pulley=NGK BKR7EIX

 

Thx i am getting a #2 cylinder misfire now. The cel comes on and goes off every so often and i get the p302 code.

I know this may not fix it but i thought it couldnt hurt either. I have to order the spark plug tool so i can pull it out and see whats up, and maybe get a compression gauge not sure if all gauges are the same or i need a special one for the mini.

The car runs fine after the light goes out so im not sure whats wrong.

 

You don't say how many miles on the coil, plugs and wires. First thing I'd do is pull the boots off the coil and clean the corrosion off the coil terminals and inside the corresponding ignition wire terminals. See if that helps the situation before throwing $ at the problem.

 

Opps.....it has 28,600 miles on it.

 

Other than checking for corrosion on the coil pack plug, with that few miles, no pulley, the plugs and wires are almost new...by miles anyway...
Plugs, coil and wires imo are likely a waste of $$ with so few miles unless they are faulty...just tossing parts at a problem hopeing it may fix it is not usually a cost effective way to deal with a problem...
If you do pull the plugs, do use a tourqe wrench to reinstall them.....
The compression check will give you a better idea whats going on....IF you lnow how to do it and interpert the results...sounds of where the air is leaking from, wet/dry....might be worth paying a couple $$ to get it done and a pro's opinion.

 

Thx i do plan on checking it before i just wanted to get a idea if it was even worth doing as just a upgrade not so much as fixing the cel. But from what i read there is no need to do the upgrade parts since its the same as stock.

I will switch plug wires one and two around see if its the wires first, then pull the plug once i get the socket for it.

Thx guys.

 

Yes you should inspect & clean terminals on the coil, and of course make sure the wire boots are seated properly.

But before you swap plug wires around, pull the plugs first to see if there's a visable difference, and when you do make sure that #2 was tight (could possible be the problem also)

Special tool? Small sparkplug socket w/ the rubber insert removed or 5/8 deep well socket
and
One of these:


Use the telescoping claw to also re-insert the plugs & get them started.

Torque to 22 ft/lb (TORQUEING PLUGS IS A MUST)

After doing both of these things, clear the code & drive the car & see what happens.

Still the same problem on the same cylinder, then do the wire swap, don't forget, diagnose one step at a time.

 

Ok thx i will do that first and see how it goes. Gotta love this website lots of great people here and very helpful.

 

BTW, Walmart had some of those telescoping claws w/ a light on the tip, I've actually found it to be pretty handy.

 

Suggestion: Before pulling the plugs, I use an air compressor and a fine nozzle to blow out any debris in the spark plug well. You don't want anything dropping down in there! I know this is like discussing brands of oil but, keep in mind, this is an Aluminum head. I use a smidgen of anti-seize on the threads and only torque to 20 lb.ft. max. Also, I use a 3/8" extension on a magnetic spark plug socket and use a strip of duct tape to make sure they don't separate.