spark plugs for 110 engine

[desert]

What would be the best spark plugs for the 110 engine in my 85 280SL Euro? (61K miles) Thanks, Desert

[tgolden]

Originally Posted by desert

What would be the best spark plugs for the 110 engine in my 85 280SL Euro? (61K miles) Thanks, Desert

The ones the owner's manual calls out; the OEM plugs.

Years ago I tried platinum core plugs in my 1984 280SL w/ M110.990 (Euro); the parts guy at my local parts store crossed the original spec to the platinum core and the performance was poor. I've had good performance from the original spec OEM plugs.

Regards

[rs899]

You probably need a non-resistor Bosch plug that is no longer made. Try an NGK equivalent.

[desert]

Thanks, I contacted NGK by phone on their Tech Advise line and they reccomened the BP6ES 7811 non resister and not the high priced one. "iredem" or whatever it is.....Desert

[rs899]

That sounds right. I think I have BP5ES in my 380SL, but that may be too hot

[desert]

Here's a follow up....I put the NGK non resister plugs in and now my radio sounds like a machine gun when it's on AM. Guess I'll go back to the Bosch. Maybe there is a cure for the radio noise with non resister plugs but I'm not aware of one, any suggestions?.....Thanks Desert

[RadioTek]

You may be able to use resistor type plugs. The noise on your radio with non-resistor plugs suggests that the plug wires and connectors have been changed out.

The original setup was non-resistor plugs with resistors in the plug connector. You need to have a resistor in the line somewhere, otherwise it will put out RF noise. There are also some theories about getting better spark due to the current buildup with the resistor.

If someone used a plug wire set without the resistor, then you need to have the resistor type plugs.

The problem comes when you have either two resistors or no resistors. With two resistors, the spark voltage is decreased and you get poor spark.

Scott

[desert]

Thanks....I put new Bosch resistor plugs in and that pretty well solved the problem although it still gets some spark noise when in a garage or under cover but is fine when it's out in the open. I think I'll go ahead and put new wires in since some of the wires when jiggled cause the spark noise to increase or decrease. The wires in there now just might be the originals, I'll have to go through many receipts to see if they have been replaced over the years during tune ups. Question: are replacement wires also blue or just the originals? That might help determine if they are original or not....Desert

[nobby]

BERU wires are gray.

I just installed a new set of MAGNECOR wires which are black and are 7MM.
They have an 8MM set that are blue.


And they fit great....as did the BERU wires.