I have read every thread I could find on how to drain and fill the coolant system, burping it, and the tricks involved.

I have some questions for all those that have tackled their own coolant system work on their favorite Fiero.

1 - What is the simplest method of draining the system? The petcock on the radiator seems impossible to get at let alone have fluid drain out of, as the lower support for the radiator (or whatever it is) seems to be in the perfect position to have fluid drain onto the car instead of out to a pan. One method mentions removing the plugs from the tubes that run under the car, but to drain them requires that the car be level. I have one set of ramps, so I can raise the front or rear, but how do you get under the car and still have it level? Jack stands I suppose??? Seems like an awful lot of trouble for something that seems simple enough - at least in concept.

2 - When the system is drained and flushed, and you are ready to refill the system, what is the best way to "burp" our little baby Fiero? I have read about parking on an incline, opening the front radiator cap, and refilling there until the gurgling sound goes away. I have also read Ogre's recommendation about removing the heater line, but that concerns me. Hot fluid gushing out all over doesn't seem safe to me. I know you will start with cool fluids, but things will heat up rapidly - right?

3 - I have read somewhere that you should check in the shroud or somewhere around the radiator for debris that gets caught in there. Does anyone know about this and where it is located? Pictures and/or descriptions would be helpful. Having a clear way for air to get past the radiator will make the system as efficient as it can be.

4 - I finally got around to checking the coolant overflow bottle and the level was non-existent. I know enough to see this as not an entirely good thing, but I have not had any overheat issues other than some weird brief peaks in temperature (above what I normally see) during really hot days, while driving in traffic. One clue is that when I start the car, I get a rushing fluid sound coming from the passenger side floor area. It goes away within a few seconds, but it still concerns me. Could this be trapped air in the system? Is some amount of air in the system unavoidable?

TIA to whomever answers...

I drain the system from the radiator, never been lucky enough to have the plugs actually come out of the under body lines. The radiator drain is not too hard to get at from under the car, though it may be somewhat stuck. I just used a pair of pliers. If you can get the plugs out of the pipe, no reason to raise the car. Just place a large shallow pan under them. You may need to put the plugs back in and drain the pans though.

Here's how I filled it:
http://fierodomain.com/content/view/260/100/

As for that gurgling sound when you first go to start, most likely just fuel returning to your tank from the pressure regulator. That is normal.

And you should never let the reservoir get empty or even below the "Add" level, sucking in air will ruin the effectiveness of the system. And if there is no fluid in there, you must be low on coolant.

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Here are my experiences on Fiero coolant systems.
Q1 - Use the pipe plugs on the coolant pipes to drain. Passenger side allows a little more coolant out, as it is low side of raditor. I use a cement mixing pan to catch the coolant, slides under the car, no jacking required. Reinstall plug(s) with teflon sealant.

Q2 - I park the car on an incline and keep filling. Use a raditor cap with a vent lever to help with the burping process.

Q3 - I think the shroud needs to be check around the radiator, that it is intact. Check the front of the radiator for things for plastic grocery bags or other items that are picked up on the road. If many of the cooling fins are bent, they will block air flow. Check for debris stuck between the radiator and A/C condenser if present.

Q4 - The coolant tank could be cracked or the hose to the tank leaking. The rushing sound on my car tells me time to check for coolant leaks.

Tips - Other Fiero owner know that turing the A/C on will active the cooling fan and bring down the temps when stopped in traffic.
The parts catalogs list the wrong radiator cap for Fieros. even wrong in my Fiero owners manual. Stock radiator cap - AC part RC27
I'm using Stant Lever vent cap - # 11330
If your coolant tank is OK, clean out the inside by removing it, add a handful of small rocks, then agitate and rinse ( remove rock before reinstall ).

Park on a hill nose down.
The radiator drain is as easy as any other car, but I usually pull the bottom hose to do it faster, its a little more messy. The drain plugs in my coolant pipes under teh car came out ok, remove those,open the radiator cap and the cap on the thermostat (on the engine) when they are all pulled let it all drain.
Then you can put the drain plugs back in the pipes and the hose back on the rad.
Pour a 50/50 mix, distilled water and coolant into the thermostat cap until the radiator is full, then cap the radiator.
Keep filling until the stat housing is full, put the cap on and start it up, open the cap right away so no pressure builds up, add mix until its full again while running.
Then what I did was let it sit with the cap off, check it about every 5 minutes and add more. When it seems to be holding, run it a few minutes with the cap off (put it on while starting) and then check again.

For some people it works easy, sometimes it doesn't, if you take it for a drive and it starts getting hot, you still have a bubble in the system, ***don't keep driving if its getting too hot.

[This message has been edited by 2.5 (edited 07-06-2007).]

quote Originally posted by Xanth: I drain the system from the radiator, never been lucky enough to have the plugs actually come out of the under body lines. The radiator drain is not too hard to get at from under the car, though it may be somewhat stuck. I just used a pair of pliers. If you can get the plugs out of the pipe, no reason to raise the car. Just place a large shallow pan under them. You may need to put the plugs back in and drain the pans though. Here's how I filled it: http://fierodomain.com/content/view/260/100/

I will try draining from the radiator, but that flat metal piece under the radiator will make getting the coolant into a pan without having run all over a real PITA. I am trying to fit some small chunks of fuel line around the drain tube. I found a thin walled piece that I used to repair my motorcycle works pretty well, but I will have to hold it in place, as it does not want to stay on by itself. But it should work well enough to drain most of the coolant where I want it to go...

Is there any trick anyone knows to keeping the right angles on the car (front lower than back) and still being able to get to the radiator drain? Or am I going at this the wrong way? Are jack stands the answer?

quote As for that gurgling sound when you first go to start, most likely just fuel returning to your tank from the pressure regulator. That is normal. And you should never let the reservoir get empty or even below the "Add" level, sucking in air will ruin the effectiveness of the system. And if there is no fluid in there, you must be low on coolant.

I will re-check the coolant bottle, as I added some 50/50 mixture just the other day. I will also take a look inside the thermostat housing, since being low there may be the result of the air creating a pocket at the highest point in the system. Most likely the sound I am hearing is the coolant circulating and the air in the system rushing by. I only say this due to the location of the sound, as it seems to be coming from the passenger side floor area, and not the center console where the gas tank is.

Thanks for the recommendations Xanth.

Almost forgot, don't put the stat in until you think your bubbles are gone. Idle it without one.

That fluid rushing sound is probably from your heater core, I have had alot of cars make that sound. Should not mean any problem.

Jacking: I just jacked up the back so the tires were off the ground a few inches, then put jackstands in.

[This message has been edited by 2.5 (edited 07-06-2007).]

The coolant pipe plugs can be stubborn. A 3/16 inch allen wrench and PB Blaster should get them out. Plugs are located on each side coolant pipe, just behind the rear edge of the car door. Using the plugs require no crawling under the car and the coolant drains with less spillage.

The cap I use is a non-vented cap, but it has a lever to vent the pressure. The vent / no-vent design refers to the cap's check valve design. A spring loaded check valve is required for the Fiero. On a non-vented cap, if you look on the bottom of the cap ther is about a 3/4 inch disk that is held closed by spring.

To check the space between the two cores, move back the vinyl strip that sits on top of the radaitor. There is a one inch gap between the radaitor and condensor.

Pulling the stat as 2.5 suggests will speed up the burping process. I have read about others drilling a small vent hole in the stat to help the process.
Filling the cooling system follows simple physics - air seeks the high spot and water goes to the low spot.

I suggest using the drain plugs, they are pretty much the lowest part of the system and you should get more fluid out of the system than draining from the radiator. IMHO
******************BEWARE*******************
The drain plugs and the tubes are stainless steel, you must use teflon, neverseize or some type of thread sealant when you reinstall these Plugs. A Stainless Steel to Stainless Steel connection will seize without some type of lube. Install these dry, without lube, and you will never ever get these apart without drilling out and re-tapping.

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