Drilling thermostat

[Halon]

AS OF 8-23-07
New Mishimoto all aluminum radiator
2 fans wired always on
160* thermostat, holes drilled, and now just completely removed
different coolant mixtures, and redline water wetter
new oem mitsu headgasket
new coolant line and clamp
new gaskets
new rad cap
vented hood
new water pump (better design then what was in there) and o-ring
burped numerous times




OK in my never ending quest to figure out what in the heck is going on with my car, I'm back to the thermostat again. My car runs hot mainly when driving on the freeways. Hot as in the needle starts to move past straight up and down and I get scared and stop. If I crank the heater, this helps quite a bit, but it sucks driving everywhere with the heater blasting.

So I've been reading up about how people drill little holes in their t-stat. Now I'm staring at mine, and the only spot there's any room to drill, is the big ring around the edge. But I don't see what that would do, that's not the part that moves up and down. Plus there's already a large opening in the top, where the rod connects to. Anyone able to clear this up for me at all?

BTW, car is a 91 tsi. Thermostat is a 160* one from AZ.

Other things I'm doing right now is replacing all the coolant. Going to go with a new mix of maybe like 65water/35antifreeze. Also dumping a bottle of water wetter in. It doesn't appear that I'm losing coolant, but sometimes I think I can smell some. But everytime I pop off the cap, it's full to the top, and the overflow doesn't seem to be budging at all.

[blageo23]

Im assuming its a new Tstat. Drilling a whole in the tstat will let coolant flow through the engine even when the tstat is closed. So drilling into the metal ring will do what you are talking about.

[Halon]

I understand that drilling a hole is supposed to allow coolant to pass while it's closed. But I am staring at this thing, and I don't see how that is the case. There are 2 huge openings at the top of this. This ring never moves, nor does anything ever seem to seal up against it. So I don't understand.

[EclipseGST]

Drill on the outside of those 2 openings on the silver/metal part.

If you are wondering how it opens/seals, go boil a pan of water and stick the T-stat in with a pair of pliers. You can watch it work...

[Halon]

I did just do that about an hour ago actually, because I was curious. But I mean, the center piece is what seemed to move, not the big metal ring around the edge. And still, there are those 2 huge openings in the center, so I don't see what my little holes are going to do because coolant could already go through the big openings in the center. But I'll quit trying to understand I suppose, and just go drill the dumb holes. Thanks!!!!

[Super Bleeder!!]

Have you pressure tested your radiator cap?

[Halon]

Brand new radiator cap.

I just noticed something. My drivers side fan is working intermittently. That is the one I've always had wired constantly on per RRE's reccomendation, because it sits right in front of the turbo and helps to blow the hot air away from the radiator. That was coming on and off quite a bit. Wiggling the wires would make it come on and off. Finally it just hard failed it looks like. Now I'm looking for a new slim fan. I hope this is it.

[Super Bleeder!!]

Brand new doesnt mean its good!

[Halon]

How do you pressure test a radiator cap? I don't even think my old cap was bad, but I replaced it anyway. And with the new one, the car acts the same way.

I did drill the holes, but they didn't do anything. I just got the new fan put in, so now we'll see if that helps at all. I sure hope so.

[twack]

Do you have a fan on the passenger side? That fan takes most of the heat exchange in 1Gs because the inlet and outlet and both on the passenger side not in the middle and the majority of heat will be on the passenger side. put a fan on there.