ItsJ2

My 99 clk430 is little over 5 years old, I am ready to replace all 16 spark plugs, any suggestions ?

According to the Bosch website, the following 3 types fits the clk430

Bosch Spark Plugs

1. O.E. platinum(single electrode)
they are $12.99 a piece at local autoparts store, $12.00 from the dealer

2. Platinum2(2 electrode)
$3.99 each

3. Platinum+4
heard mixed result from the +4, will skip

will probably go with the Platinum2, anybody have any experience / problems with them ??

Hal H

The issue(s) with the multi-ground electrode plugs (bosch +2, +4 is that you cannot adjust the gap to the spec the MB ignition system calls for. They have a large side-gap (about 1.6mm) type of electrode and might not work very well with the stock ignition.

I would check to see if the stock plug is single platinum (center electrode only) or an iridium plug.

If it uses single platinum plug, a double platinum (Autolite, NGK) would be a better choice and not that expensive. There will be very little erosion and the gap will last for the life of the plug.

If the stock plug is iridium, use the same type.

I tried the +4 in my GM car, and they didn't work - gap was an issue. When I went to the standard single electrode plug (where I could set the gap), everything worked fine again.

Since you have to buy 16 plugs for the 4.3 V8, I would get something that will work the first time around and not have to replace the plugs all over if the experiment didn't work.

lz_clk

I've had problems with the Bosch platinums before and wouldn't recommend them to anyone.

I would either get a copper plug if you want to go a budget route. IMHO copper plugs are much better than platinum, or get an iridium like NGK or Denso if you didn't care about the $$.

Bagher

I went the Autolite route and now my check engine light is on. I have a set of Bosche O.E. platinum plugs waiting to be put in.

ItsJ2

what type of Autolite did you get ?? did you set the correct gap ?

I bought an OE Bosch from the dealer just to take a look, paid $12.00 for it
I thought it has been correctly gapped for my car, but its not , it came brand new in box with 1mm gap, clk requires 0.39mm Gap.

Bagher

I got the autolite platinum. I did not set the gap as I have never set the gap on any spark plug changes on my previous cars and never had a problem, could this be why the check engine light is on? the codes I have are :

P0170 Bank 1
P0173 Bank 2

Hal H

I thought misfire codes were P0301, 302, etc. (the last digit denotes which cylinder)

The correct gap is always a good idea though - too large a gap will cause misfires under load.

I took a look in the owners manual for my 2001 (under Engine electrical) for the service parts and it lists the specific plug models for Bosch, Beru and NGK
and the plug gap.

Since there might be specfic heat ranges according to model year, I would recoomend check the owner's manual for your specific model year.