NGK BP5ES vs BP5EFS - PeachParts Mercedes-Benz Forum

xaliscomex · #1 10-26-2014, 11:42 AM

Just trying to get a few more questions answered.

I own a 1988 300sel (w126)

I decided that I'm going to go with NGK non resistor plugs

Now the question is,

Do I use NGK BP5ES or NGK BP5EFS?

I read that one has the crush washer(BP5ES) and the other plug has no crush washer and is tapered for correct seating.

I also read that some just remove the crush washer and then such plug becomes a BP5EFS.

Do I have the correct information?

And is a .030-.032 gap correct?

I called my local auto parts shop and they have 8 of the BP5ES plugs in stock

Please advise

JamesDean · #2 10-26-2014, 01:22 PM

For the M103 you want the BP5ES ones. You can use those or Denso T20-EPU's. I have the Denso's in my 190E right now.

BP5EFS are used on M116/M117 engines.

Edit: Got them backwards. Fixed now!

xaliscomex · #3 10-26-2014, 02:37 PM

what about the "F".

My current plugs have no washer and are tapered.

The BP5ES have washers

Please advise

JamesDean · #4 10-26-2014, 02:40 PM

What are your current plugs' part number/mfg?

The Denso T20EP-U are a better (visually) looking match. IIRC, I dont think I've actually used the NGK's in my M103. A friend of mine did though. I just used the Denso's.

T20EP-U

BP5ES

I use BP5EFS in my M116

xaliscomex · #5 10-26-2014, 03:21 PM

The ones I have look more like the Denso T20EP-U

pmckechnie · #6 10-26-2014, 06:01 PM

I'm getting confused about this thread. I use BP5ES (no F) in my 500 which is a 117 engine. The BP5ES is the crush washer type.

Have I been wrong all these years. I have put at least 4 sets of BP5ES plugs in over the last 12 years.

If you have a tapered seat plug in your 300 now than I believe you need the BP5EFS plugs.

PaulM

JamesDean · #7 10-26-2014, 06:47 PM

Quote:

Originally Posted by pmckechnie

I'm getting confused about this thread. I use BP5ES (no F) in my 500 which is a 117 engine. The BP5ES is the crush washer type.

Have I been wrong all these years. I have put at least 4 sets of BP5ES plugs in over the last 12 years.

If you have a tapered seat plug in your 300 now than I believe you need the BP5EFS plugs.

PaulM

This is where I got the BP5EFS in M116/M117 engines from:
M116-M117 Spark Plug Questions?

pmckechnie · #8 10-26-2014, 07:24 PM

I have looked a two sites with peach parts being one of them and found that the 116/117 engines take a flat seat spark plug like the W9DC or BP5ES.

The 103 in the 300SEL takes a HW9DC or BP5EFS tapered seat plug.

So the 116/117 have the flat seat with a crush washer which is the BP5ES.

The 103 has a tapered seat which is the BP5EFS.

Are we discussing the same thing from different angles?

I think xaliscomex needs NGK BP5EFS taper seat plugs

I believe a gap of .030 to .032 inches will work great.

PaulM

JamesDean · #9 10-26-2014, 08:20 PM

Yes we must be Paul. I've reversed these two plug models a few times before and still sometimes get them mixed up.

I just pulled a plug out of my 420SEL, BP5ES. I had to use the larger of the two spark plug sockets. The larger socket does not work on the T20EP-U's which fit the M103.

Yes. The M103 gets the BP5EFS.

If you can get them locally, order them OR the Denso T20EP-U's online somewhere.

Sorry for any confusion