I recently bought a stant thermostat , o-ring and thermo neck from mazdatrix. The Mazdatrix neck is cracked so they are sending me a new o-ring and neck.

Well, since I am removing all of this stuff again, I figure I might as well find a way to either A) drill a hole in the top where the jiggle pin would be or B) drill a hole and fit the jiggle pin in the hole.

Problem is, I am VERY afraid to try and fit that pin in the hole due to the possibility of it falling out and trashing something down the line.

Would just drilling a small hole do the trick? Yes, I know it'll let a bit of coolant go by but it shouldn't let enough get by to have any effect on the thermostat or operating temp should it?

The reason I want to do this is because last time it was a total bitch getting the air out of the system without the jiggle pin.

 

Drill a 1/8" hole at the top. It will work just fine.

 

That's what I figured, just wanted to check. Thanks jackchild.

 

I drilled an extra hole in my OEM 'stat right by the jiggle pin. I get a little slower warm up, but I am sure any bubbles move on past.

 

Any noticeable coolant temp changes besides slightly longer warmup?

 

None whatsoever. I used to feel some heat by the end of my neighborhood-1/4 mile; Now I feel some heat at about 1/2 to 1 mile, depending on outdoor temps. I drove out of my neighborhood the other day at 9*F 4:30 am to teach a class. I had needle movement on my VDO gauge at 1/4 mile, full warmup-180* at 2 miles.

 

Sounds about right.

If I remember correctly the jiggle pin would normally be located at the top of the thermostat, and slightly off to the right when looking at it from the passenger side correct? I just want to make sure I drill this hole in the right place. I guess drilling the hole exactly at the top most portion of the thermostat would be okay(topmost meaning topmost portion in relation to the angle it sits in the housing).

 

That is the way the thermostat is supposed to be oriented, around 1 o'clock viewed from the passenger side. I drilled my extra hole at 12 o'clock.

 

just was i was looking for...
where do i drill the hole anfd how deep i as well dont feel like damaging something major... thanks.

 

there is a supporting ring on the thermostat, that the oring attaches to. You need to drill the hole through that. Make sure you dont drill too close to the edge of the ring nor too close to the edge of the actual thermostat device itself.

 

I had a drilled Stant thermostat like 5 years ago on my GTU.

 

damn it....
where exactly?

 

do you know where the jiggle pin is on the stock thermostat? just drill it in a place like that. it's really anywhere on the housing except in the middle where the thermal element is

 

Here is a pic I made to show you.

 

jjwalker ur are ******* legit thanks!!!!

 

What is the point of the jiggle pin in the hole exactly? Is it just a restriction so the hole can be larger without bypassing too much coolant?

 

Air can get trapped underneath the thermostat because it is the highest point in the system, thus not allowing the thermostat to open. That pin is actually a valve. it will let air past the thermostat, but when water is up against the pin, there is a float that closes the valve and doesn't let coolant bypass.

Running without a pin/hole for air to bypass is just asking to kill your engine at some point.

 

dang i keep getting pressure even after the hole.... when i first installed it, it was fine no pressure now it decides to accumulate pressure again it took it a whole 2 days... now wat? im looking at my other hoses and they seen fine, the ones to the heater core ... no leaking no cracks... i wonder where the air is coming from no champagne bubbles either.... its just my hose on top of my radiator to the neck that gets pressurized... and seeps throught the filler cap... i noticed it only does it at higher rpms because i drove the car for 10 miles at low rpms and all was fine... i ran the car with out the filler cap and saw that as i would give the car gas the coolant would run through the motor and as soon as i eased thee throttle it would accumulate way too much coolant and overflow the neck? any ideas?

 

You *DO* realize that a normal cooling system is *supposed* to pressurize? The hoses should be tight as a tick. The behavior you are describing with the cap off is normal. I think you may be just freaking out over absolutely nothing whatsoever.

 

what would happen if you didnt install the t-stat with jiggle pin at 1 o'clock position?? (i never knew this)

 

jackchild. i know the system is supposed to be pressurized, but is it normal for the top hose to become really pressurized to the point where it looks inflated even after turning the car off? i decided to block the filler neck off because i seen the little plastic cap assembly piece cracked and i found where the leak was coming from and i had thought that maybe this is where my system was sucking in air. i was right about the leak but i still have the pressure...
thanks guys.

 

With stock hoses? No.

Replacement hoses typically seem to be thicker, and if you use worm clamps, they will "Look" inflated but they aren't. Who knows. To answer that question we really have to have a picture if you can get one.

gkarmadi,

It isn't functional at that point. Air is bouyant and will be at the top, so basically, if the pin isn't at 12 or 1 o'clock, it isn't serving any purpose.

 

picture will be posted shortly. i have already had the car off for thirty minutes and still the hose remains inflated....

 

 

i put the hose clamp in between as well to show you guys how much its inflated...