i noticed that my rad cap (cap on water pump) seal was torn a little bit... the car would not over heat but the needle would move enough that I could notice and begin to worry me. I went to autozone and bought a new one. The cap almost looks like the one from the aluminum ast, where it has the little sping seal on it. after that my temp needle stayed pinned in the center, even with lots of boost or just crusing around...I also live in florida and its been in the 80's high 70 the past few days

just figured id share with everyone so they could se how just a cap can effect temps, and how 8 bucks can fix it. and give some piece of mind

 

i haven't experienced this first hand, but i have heard several stories of buying 3rd party parts like the rad cap. get a oem one from Ray, i'm sure it'll be around the same price (i forgot how much i paid for mine).

 

you have a temp gauge right? your noting going off the stock one? cause that **** is way out of wack....when i do a side by side on my pfc it shows that it is wayyyy the **** off. and always get oem stuff...

 

I'm a little confused by your post. So the rubber seal on your cap was torn, right?
Well, did you notice any signs of coolant leaking out from underneath it, or steam coming out from it? If you didn't, doesn't that indicate the cap was sealing?

It may be that what happened was that the new spring seal cap upped the pressure in the system, not that the previous cap was lowering the pressure.

But I could be wrong. Can you clarify?

 

^What he said

 

it was not leaking or steaming from what I saw. no evidence of it anyways. I just noticed that it was torn. Yes i am using the stock temp guage. I just noticed that it would move about | | much up or down from center position where it is supposed to be. So one day I decided to change it. and it has not moved since. Maybe the tear allowed air to get into the system or something. i dont know....all i know it that changing the cap fixed my problem, and i figured id share.

 

Thanks for sharing, simple fixes are nice, and maybe this will remind others to change their filler caps before they fail.



FYI, a slight movement of the coolant gauge means you might have been experiencing BIG problems.


https://www.rx7club.com/3rd-generation-specific-1993-2002-16/big-fat-fd3s-cooling-thread-571088/
^see section 2: Measurements


-s-

 

when it moved...it would move only between these 2 areas. not very much in between the white lines i drew on the pic

 

i love it... 150-230*F......

"cold"

"hot"

"rebuild"