Melted Piston

[N1CKY]

Took the car home because it was running on 3 pots, Took number 3 plug out to find the electrode had snapped/melted off.

Took the head of and found a melted piston, Then took the piston out to find the destruction.

Any ideas what could of caused it ? Just a dodgy plug ? Timing was all spot on, never skipped a tooth or dropped a valve etc. Valves are mint. All this after 300 miles after a full engine rebuild.

 

[Robin]

Running too lean is the most common cause of this on G40's.

[Andy]

Or the wrong plugs, or too much ignition timing.

[N1CKY]

plugs are super 4 bosch r6 982 the timing is what it as been on what i have been told 8 deg when warm an temp blue plug disconnected

i need a piston any one got one thanks

[Andy]

1. Those are the wrong plugs.
2. That base timing is too advanced.

[N1CKY]

what are the correct plugs an what is the correct timing

[Andy]

1. Bosch W5DP0
2. 5° (+/-1°)

[Jacque]

Hi i have a question related to this result :p (running to lean, dont know)

My polo does an average of +- 33.5 mpg for the last 7000 miles (since i bought it +- 2 years ago)

it has an SLS chip (140hp) on 68mm pulley, bosh sparks (came with the kit) and standard injectors.

my wallet loves the mpg, but i m a bit concerned about wether is uses enough fuel and not to few.

i think it's about just ok, just would like a second opinion.

anybody?

[Andy]

Sounds about right.