Hey chaps, hows it going ?
I own a 1998 CLK230 Kompressor and i have to admit i love this car besides a few issues here and there (Mostly build quality sounds :p) but in general its great!
Anyways the car is atm at around 87k miles and well im looking to change its spark plugs as im sure it hasnt been done for a while in this car (Because i have a Rough Idle and at cold mornings the car is a bit lazy until the engine gets into temperature and MPG's are struggling at around 19-20MPG...so i believe its the spark plugs that are failing)

My question is ,which spark plugs do ya recommend me ? I've been reading around that Iridium IFR6D10 works great for '00 230k models but mine is '98 so...i dont know for sure hehe.

Awaiting your suggestions and Thanks in Advance

Respect~~

 

I have the same car and use Denso Irridiums and I am very happy with the performance. They last a lot longer then normal plugs 30+K and I noticed smoother running expecially in the winter mornings. They are about 3 times the price but are worth it.
However I am a little concerned at your low 20MPG. ? Even new plugs I dont think will improve much for you. You should be getting about 20 - 24MPG in town and at least 34MPG on the highway. check your MAF perhaps too and also the oxygen sensor nearest the engine on the exhaust as this will effect MPH .

 

Good day AlphaWing, I too drive a 99clk 230k and have recently replaced my plugs due to misfires under heavy acceleration. I purchased a set of NGK IFR6D10 iridiums for approximately $47 on AutohausAZ and i must say i am VERY PLEASED with the peformance and smoothness of the engine and would definately recommend them. However seemingly that your mpg is low i would recommend exploring your MAF and oxygen sensors as AE1K suggested. I took my maf out last weekend and it was coated in oil so my breathers are blocked and my MAF is now on its way out. i tried spraying an electrical contact cleaner on the filament but it didnt work, so i ordered a new one. BUT as a side note if your are having misfires, stumbling, hesitation before accelerating and when you "kick down" it holds the gear and doesnt want to change gear until you slightly ease of the throttle. The Mass airflow sensor is definately your problem.

Take care and hope this helps

 

Thanks both of ya's for your answers. Im definetly going to get those NGK IFR6D10 iridiums.

And btw about the MAF being the fault...its true i had a MAF problem but i've replaced it with a 2nd hand one (Couldnt afford getting a new one back then).
But i dont think its the MAF because i tried disconnecting it to see if on Default the car runs smooth but nope....the car runs VERY unstable and if i try to push the accelerator i get alot of Negative feedback with the MAF Disconnected with the car still having a rough idle.. also i keep cleaning it each month or so, so i believe the MAF works good (Thought i might be wrong...problem is i dont know anyone who has another CLK with a new good working one to test it out :s)

Also A1EK you said something about Oxygen Sensor? Where is it placed and how do i know if its defective or not?

Respect to both of ya's.

 

Its not always true that if you disconnect the MAF you car runs better, I too found that my car ran very poor without the MAF plugged in. You said that you clean the MAF every month ,,, DONT Do that, your MAF does not need cleaning for no reason. If you are cleaning the MAF because its got oil on it, then it wont last long and you need to get to root cause, as the guy in Jamaica said your breathers are probably blocked. You need to remove the inlet manifold and use some thin wire to clean out the blocked nozzles, (Search the forum theres good DIY, in fact I think I did a write up with photos if you search with my name ).

 

Morning again.

First of all ... Thanks for the tips! What you say makes sence... i always woundered that XD
I'm gonna search for an DIY around on how to remove the inlet manifold and so clear the blocked nozzles (Hope it aint too difficult XD). Also ill try to look for a new maf , where did you find yours and for how much ?

Respect