A few years ago I removed it. If I remember correctly it was broken and I didn't see any harm in just replacing it with a non restrictive hose barb.

Lately I have been feeling that this might be the reason my heater does not blow as hot as it used to so I was considering replacing the restrictor or incorporating an inline restrictor to accomplish the same task by slowing the flow of coolant.

Could someone explain the purpose of this part and confirm that the absence of it is in fact the reason for my not so hot heater?

What other issues might arise from omitting it? Engine takes longer to warm up, or??

My heater will blow hot when I am on the gas, but not so much at idle, whereas before it was hot all the time. I currently have a 190 thermostat (highest I could find).

If this little restrictor has nothing to do with my heating issue, please advise on possible causes. Car is properly burped with no air in the lines. I installed a manual valve inline just outside the heater core which releases any air and allows any coolant to flow back to the overflow while releasing air.

Thanks

Yes that could be longer warm up time and other problems.
But
No, this isn't heater output to cabin problem. Bad/blocked heater core, plumbing and/or Tstat. New Tstat eliminates one item.

Added valve to bleed heater is Not needed. Heater loop will blurb air w/out your help.

See my Cave, Heater, Coolant Fill and Thermostat
------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 11-12-2014).]

I'm thinking that it could cause the problem.
Does the engine always come up to temp and stay there? Or does the temp drop significantly?
The heater loop is a separate loop that bypasses the thermostat. It's actually a small radiator. If it cools the engine sufficiently, it's conceivable that the thermostat may not ever open fully, or may close. The restriction would ensure that the coolant remains in the block longer, and absorbs more heat.

Having said all that, I have a 2010 G6 with a 3.5. The coolant temp gauge never moves when it's at operating temp. When I climb on the gas, the heat blows warmer than it does when I'm just cruising. Other cars I've owned did the same thing.

[This message has been edited by Raydar (edited 11-12-2014).]

Thanks for the replies. My thermostat is only a couple months old and I have been pretty good about maintenance on the cooling system since I have owned this one. My very first coolant change was not pretty, but after a nice flush and a new engine, radiator and heater core... all of my coolant flush/changes have left me wondering if I even needed to change the coolant as it still looked perfect.

I just ordered one of these (the one on the left in the pic)

quote Added valve to bleed heater is Not needed. Heater loop will blurb air w/out your help.

How does this occur? Isn't the heater hose just outside the heater core the highest point in a sealed system? This was my reasoning for placing the brass T valve there. It is always closed allowing coolant to flow normally. The "T" is piped over to the coolant overflow and sometimes at operating temp I can open the valve and a bit of air escapes followed by some coolant at which point I shut off the valve.

It seems like the only other location any venting would occur is through the tube just beneath the radiator cap.

[This message has been edited by perceptionist (edited 11-13-2014).]

quote Originally posted by perceptionist: How does this occur? Isn't the heater hose just outside the heater core the highest point in a sealed system?

No. Fiero Tstat cap is highest point but doesn't matter to heater, or even Tstat housing or engine...

Tstat close then WP will try to force all coolant flow to heater.
The amount of flow will forces most/all air out of heater loop. (compare to river rapids) Any trapped air left over will move over time.
Even Tstat housing and engine will purge some air to radiator because of coolant flow. (Coolant level too low will stop that.)
Radiator have enough tubes to slow down coolant flow (like fat wide river) and let air to stagnant and stay there.
The Radiator cap will purge that air thru overflow tank when system get hot.

Note: Heater core looks like but not same thing are radiator.
Core flow... inlet pipe thru bottom/top half of core to other tank then return to top/bottom then return to engine.

Many times people saying to burp the system because often many have air leaks when engine cools down or did not fill system right. (Jack the car etc to burp the system then have big system problem or have no clue.)

A fact many don't get... Cooling coolant generates vacuum. What we often call radiator cap check valve is really a vacuum valve, there to suck coolant/air in a control manner. (Air if tube/cap leaks or is old car w/o overflow tank. Venting or Non-Vent caps does same job.)
Iffy cap(s), loose hose clamps, or WP seal can leak air in when engine cools.

Ah ok I see. Thank you for taking the time to explain.