Greetings.

My car is a '91 FC3S Turbo convertible and I just changed my thermostat. I replaced the old thermostat with a universal one (could not find an OEM) with the same specifications as the old one. I also tested the new thermostat by boiling it in water and it opened and closed perfectly at the right temperatures.

But, the new thermostat is slightly bigger than the old one so I could not align the jiggle pin with the upper right hole (2 o clock) as shown in the manual picture.
Instead I aligned the pin with the upper left hole (10 o clock) and then the thermostat fitted perfectly.

My questions are these:
Will this be a problem for the proper functioning of the thermostat?
Why is this alignment mentioned as a "caution" instruction in the FSM manual?

PS:My old thermostat had the jiggle pin aligned to the down right hole (4 o clock) and I never had any overheating problems.

 

should be fine, the cautionary statement is more for the 2 fixture arms that align the thermostat that can cause the stat to bind and get crushed if you don't pay attention to alignment.

 

Ok thanks for your reply.
I thought that the jiggle pin alignment had something to do with the air pockets that form in the coolant flow.

 

it does, which is why it should be at the top half of the thermostat. normally i put a jiggle pin at 12 oclock, but you can't in these housings due to how they were cast.

 

Indeed.
So its ok to have the pin aligned with the upper left bolt hole. Thanks again.