Datsun Roadster Forum-311s.org

I have the BP6ES spark plugs in my engine, and although I screw them in by hand the day I started my engine the first time, after several times of starting it to tune it up, I can't get the damn things to unscrew back out by hand........and none of my sockets fit. SO, whata size socket do I need to get for these suckers?

Jorge

You need a standard spark plug socket available at any auto supply for 1.99. They are a deeper socket and have a rubber insert in the top that goes over the insulator.
good luck.

I think it is a 13/16 spark plug socket that fits the Roadster. They also make 5/8 spark plug sockets but they are too small for the Roadster plugs. You should be able to get the box end of a 13/16 wrench on the plug if you don't have the correct socket.

If you have an aluminum head, the old rule of thumb is never remove the plugs on a hot engine. The steel and aluminum expand at different rates and the hole can actually deform. Might be why the plugs self tightened?

Heard a story (urban myth??) a guy hand tightened the spark plugs and drove off in the car, When the car started running really badly, he pulled over ....3 or 4 out of 8 plugs unscrewed themselves and were dangling by the plug wires!

dbrick wrote:Heard a story (urban myth??) a guy hand tightened the spark plugs and drove off in the car, When the car started running really badly, he pulled over ....3 or 4 out of 8 plugs unscrewed themselves and were dangling by the plug wires!

I would lean toward urban myth. Having had to run an engine with a spark plug removed, I can assure you the air rushing in and out of the spark plug hole is very hard to ignore.

I had a plug back it's self of on a honda a20 motor in my 88 accord. At first i thought i blew a head gasket because power dropped off to almost dead, she would just barely idle and it had an awful HISS HISS HISS. Luckily i was right around the corner from my house so i threw caution to the wind and limped it home expecting to find the worse case when i popped the hood. A quick visual inspection #1 spark plug was no where to be found and my electric cooling fan was making a racket and starting to burn up. I unplugged the fan harness trying to save the fan and that's when i found the plug wedged between the fan and the shroud. I guess the fan was working and caught the plug before it could eat the radiator. The fan was toast as the plastic that held the fan to the motor spindle melted.

I checked the plug and it was fine, no aluminum on the threads, checked the gap re-inserted the plug after everything had cooled down and checked the other 3 plugs. 1 other was loose enough to be able to hand tighten 1 full turn. I started her up and all is well after i replaced the fan blade ($15 at Pick-a-Part, gotta love second hand parts). That was 3 years ago on an engine that now has 207,000 all original miles.

Lesson learned, plugs can loosen in aluminum heads. I now check them with every oil change.

Keith