Remove vent pin from thermostat?

[conner]

did any one ever remove the vent pin from a new thermostat when installed and did it help or hurt?

 

[AZjeff]

No but I've drilled a 1/8" hole in the flange and oriented it up to help burp air out. SOP in 4.0 Jeep engine. Same thing.

 

[D60]

If you've already got a hole with a pin, removing the pin shouldn't help. It can't flow enough water to matter either way -- it's just for air of course.

Now if you enlarge the hole, all bets are off. I realize you're not suggesting this.

 

[Chris142]

No but I've drilled a 1/8" hole in the flange and oriented it up to help burp air out. SOP in 4.0 Jeep engine. Same thing.

Next time remove that heater hose on the housing. Fill through the radiator until fluid comes out the open hole on the housing then put the heater hoses back on.

Now continue to fill the system until full. Put the cap on and run it until its up to operating temp. Shut it off and walk away.

Check and top off after its cooled.

Thats the factory recommend way to burp that 4.0 or 2.5.

 

[Lubener]

did any one ever remove the vent pin from a new thermostat when installed and did it help or hurt?

It may help prevent the accumulation of an air pocket behind the thermostat when coolant is replaced. I always drill a small hole on a new thermostat to prevent that and it never has affected warmup time or running temperature with the engine.

 

[The_Jeff]

I drill the hole on "problem" thermostats-- ones that overshoot their given temp then slam open, over and over again. Once is normal when burping air but daily causes thermal stress to things like head gaskets.

 

[conner]

looks like a lot of guys do that with no problems .it was done on my son in laws 2010 subaru 2.5 so far no trouble.

 

[AZjeff]

Next time remove that heater hose on the housing............Thats the factory recommend way to burp that 4.0 or 2.5.

Good to know but sold the TJ so there won't be a next time. The little hole seemed to work fine when you don't know the factory method.

Removing the jiggler has been around forever.

 

[Kira]

I was told the hole was there because "you don't want pressure differentials on either side of the thermostat".
Ergo, the hole allows equalization. I never thought of it further.

So, what's the jiggle pin for?
I always assumed it was to jiggle junk free to keep the hole open.

 

[wings&wheels]

I was also always told the jiggle pin is to keep the passage clear, I would leave it. Original thermostats for my Tr6 had the pin and I always left it as I always use a tablet of GM Stop Leak when I flush coolant (original heater core, etc.) and was concerned about the passage staying open. That said, most current thermostats don't have the hole or pin, so I have drilled holes inn them and they have not plugged.