Stock '87 GL overheats at idle, radiator fan works on both speeds but has
little/no effect. I got a new thermostat (FLAPS special) and pulled the old
one. I don't remember what brand the old one is but it was supposed to be a
good one and it is far beefier in construction; iirc I got it at the local
import parts place back when but they were closed so I got this new one. Old
one is maybe 7 yrs. old, but does not have a lot of miles/cycles on it.

In boiling water, the new one opens to about 3/8" fairly quickly and also
closes fairly quickly. The old one opens (to my surprise), but to a little
less than a 1/4", and takes its sweet time opening and closing. On the one
hand, I'm thinking I might run the new one for the meantime, get myself
another 'better' one and swap them out keeping the FLAPS thermostat for a
spare. On the other hand, the old one didn't really give me much for my
money. I normally keep a spare around; I don't know what happened to it,
hence the FLAPS piece.

I know there's widely varying quality in these things, sometimes even within
brands and I've found them dead out of the box, which is why I check them (I
don't recall seeing one that 'partially' worked, however). I've also seen
ppl argue for strictly OEM thermostats here on the list but I'm a long way
from any VW dealer.

Thoughts? Recommendations?

Cya,

Robert