i noticed on a lot of the glow plugs ive been buying, they come with 2 washers on them and i was wondering if im supposed to leave both of them on or what the difference is between running one or two washers? thanks

u have to use just one of them at a time the extra one its just a spare in case you lose one of them.


Franco R

What brad glow plug? In 7 gears being in the hobby never got a glow plug with 2 washers. Yes I recommend only using one.

yeah the same as 46u. i have never had a glow plug that came with 2 washers, but as 46u said just use one.

The less washers means more compression

its like an easier way of removing a shim

Ryan

On the other hand a second washer could be enough to get the element up out of the combustion chamber enough to slow combustion and reduce the engines efficency and power. Certain engines require a long plug for a reason.
It also introduces another "weak link" so to speak that could be an air leak.

Just use one washer and if you feel the need to change the compression do it with the shims.

And one other thing, you do know that glow plug washers are directional, right? Look closely at a new washer, you'll see that it's "bowl" shaped. The bottom of the bowl goes towards the glow plug and the rim goes towards the engine head.