Thermostat and Jiggle valve Mod.

[Bigsyke]

So this is a question to russ mainly;

You said something about clipping off the jiggle valve on the thermostats, and enlarging the hole - does this only apply to nismo's?

Id assume it would help with air bubbles building up; anyone care to discuss this modification?

[orion::S14]

Don't enlarge too much...

I removed it, and drilled it out to ~3/16" (IIRC)...and drilled 2 other holes in the thermostat 'flange'.

Those three holes allowed enough coolant flow that the car wouldn't get over ~150F in the winter months here in Florida.

...

That being said, doing what you've asked about is a good idea, IMO.

- Brian

[projectRDM]

So this is a question to russ mainly;

You said something about clipping off the jiggle valve on the thermostats, and enlarging the hole - does this only apply to nismo's?

Id assume it would help with air bubbles building up; anyone care to discuss this modification?

Any thermostat benefits from this. The purpose is to have a constant bypass for air trapped behind the thermostat without allowing an increased flow of water. The OE hole is really too small to allow air to escape, and the valve creates a blockage. Just don't drill too big and make sure the hole is on top. I've had cars that wouldn't bleed before and after drilling they're fine so I now do it on every car I work on.

[Bigsyke]

As always thanks man!

[Bigsyke]

Alright to bring this to the top. I removed the thermostat. Clipped off the jiggle vavle. Bled, got all air bubbles out with the snap-on tool and proper bleeding procedures.

Now my theory on this. The car takes forever to warm up. But once its warm and moving, its as if it runs warmer than usual. Why>? I pop the hood after driving. The engine is super hot. The top radiator hose is hot, but the bottom is freezing. If I let it sit and idle for 5 minutes the lower hose starts to warm up.

Im thinking that the chilled coolant from the radiator is excaping past the thermostat from the small hole (which i hardly enlarged) and preventing the thermostat from opening while the vehicle is moving.

Its 40* here now, and the radiator fan is kicking in alot more often now than when it was 80+* out.

I assume the the wax pellet on the thermostat is on the engine side?

[surreybc]

Alright to bring this to the top. I removed the thermostat. Clipped off the jiggle vavle. Bled, got all air bubbles out with the snap-on tool and proper bleeding procedures.

Now my theory on this. The car takes forever to warm up. But once its warm and moving, its as if it runs warmer than usual. Why>? I pop the hood after driving. The engine is super hot. The top radiator hose is hot, but the bottom is freezing. If I let it sit and idle for 5 minutes the lower hose starts to warm up.

Im thinking that the chilled coolant from the radiator is excaping past the thermostat from the small hole (which i hardly enlarged) and preventing the thermostat from opening while the vehicle is moving.

Its 40* here now, and the radiator fan is kicking in alot more often now than when it was 80+* out.

I assume the the wax pellet on the thermostat is on the engine side?

not sure what a wax pellet is but the stat part of thermostat is in the engine water. you blindly listened to advice on the internet and reengineered a perfectly innocent stat. I would have just bled it properly . it might take a couple tries but everybody ends up bleeding their 240sx without mutilating their stat. this car is almost 20 yrs old and the wheel has to be reinvented every bloody time.

[Bigsyke]

Im pretty sure 90% of thermostats use a wax pellet that melts at a certain temp.

And the jiggle valve is a hole, with a restrictor. The restrictor is useless. The only reason I could see why its usefull is to restrict cold liquid from going "engine side" of the thermostat, yet still allowing air. However the concept is flawed because you cant block one and not the other.

Therefor I clipped of the valve, but im only wondering if others have had issues with the chilled water affecting the thermostat opperation

[projectRDM]

That's bizarre. I've never seen that happen on over a dozen cars, all with different setups. What radiator/fan setup are you using? It sounds like it's just so efficient that the only limitation was the thermostat, but that small an opening cannot be the only cause.

[surreybc]

Im pretty sure 90% of thermostats use a wax pellet that melts at a certain temp.

And the jiggle valve is a hole, with a restrictor. The restrictor is useless. The only reason I could see why its usefull is to restrict cold liquid from going "engine side" of the thermostat, yet still allowing air. However the concept is flawed because you cant block one and not the other.

Therefor I clipped of the valve, but im only wondering if others have had issues with the chilled water affecting the thermostat opperation

the jiggle valve only allows one way flow of air and water. like a check valve. have to go search thermostats.

"The secret of the thermostat lies in the small cylinder located on the engine-side of the device. This cylinder is filled with a wax that begins to melt at perhaps 180 degrees F (different thermostats open at different temperatures, but 180 F/82 C is a common temperature). A rod connected to the valve presses into this wax

[Bigsyke]

That's bizarre. I've never seen that happen on over a dozen cars, all with different setups. What radiator/fan setup are you using? It sounds like it's just so efficient that the only limitation was the thermostat, but that small an opening cannot be the only cause.

This was my main concern, a lazy thermostat. Your probably right. I should have a new OEM one on my desk tomorrow.
All stock cooling minus the clutch fan....I have altima fans wired to the OEM fanswitch @ 203*f, contemplating installing the z32 cap, but its winter time....

the jiggle valve only allows one way flow of air and water. like a check valve. have to go search thermostats.

"The secret of the thermostat lies in the small cylinder located on the engine-side of the device. This cylinder is filled with a wax that begins to melt at perhaps 180 degrees F (different thermostats open at different temperatures, but 180 F/82 C is a common temperature). A rod connected to the valve presses into this wax

I can see your point, and the point of the jiggle valve, however both my OEM honda and mugen look like the valve isnt always going to be a checking valve. One side is pointed while the other is flat surfaced. Both sides can potentially allow air/water to pass in both directions depending on the angle the valve is seating the thermostat. Therefor id rather eliminate it, and with a small hole the air is more likely to end up in the radiator durring the 1st and 2nd bleeding. The only concern i have is the colder water contacting the thermostat on the engine side, thus slowing the thermostats opening cycle. The thermostat could be meeting 150* water while the engine is at 200+*. Its about 40* out, When I pop my hood the radiator is cool to the touch, while the engine is burning hot, Few minutes of idling the lower hose and thermo will then open while at a complete stop. Im thinking the thermostat is seeing some of that cooler water via the hole...Or its a lazy thermostat.

I honestly think this would be really effective on a nismo.

[Mangudai]

behind the thermostat


Is this where air (if any) that is in the cooling system ends up?

[S14DB]

did you install a new themo or clip your old one?

[Bigsyke]

I tested, and clipped the old one.

[S14DB]

Chuck it, Buy a new one.