The way the system is designed has a lot to do with it... it's hard and sometimes impossible to get ALL of the air out of the system. Also take into account that it is a 20+ year old car... water pumps and radiators alike are going to break down sooner or later.
------------------ "And remember: amateurs built the ark .... professionals built the Titanic."
One thing a Fiero owner needs to look at is the cooling pipes that run from the front of the car to the back of the car. These tubes run down both sides of the car. It only takes 1 idiot to place a jack or lift in the wrong spot and the tubes get crushed. This in turn restricts the coolant flow and causes some overheating problems.
The way the system is designed has a lot to do with it... it's hard and sometimes impossible to get ALL of the air out of the system. Also take into account that it is a 20+ year old car... water pumps and radiators alike are going to break down sooner or later.
Agreed. IF there's nothing wrong with the cooling system, it shouldn't be overheating.
People who have overheating problems with their car - HAVE a problem with their cooling system they haven't managed to track down. Maybe crushed/clogged cooling pipes, radiators, and heater core, or water pumps, thermostats and fans that aren't working properly, wrong radiator cap - or even something wrong with their engine. A common culprint on the V6 is the water pump with plastic impeller that comes loose on the shaft.
My only complaint is GM used too high a setting on their cooling fan switch (closes at 235F) . Changing to one of Rodney's low temp switches brings the coolant fan on/off switching into a better range.
With everything working properly, my cars have never overheated.
I have one of each (V6 and duke), and neither overheats. Like fierosound, I have Rodney's 200/210 fan switch in my 6. The duke is an 88, so the ECM controls the fan (no switch). It hardly ever comes on except when I'm running the AC. It doesn't seem to be needed that much.
IP: Logged
09:46 PM
Old Lar Member
Posts: 13798 From: Palm Bay, Florida Registered: Nov 1999
After 22 years with the same Fiero that has not had overheating problems. I've had the cooling system flushed every couple of years when it was new and not quite as frequently for the past few years as the car is driven 5000 miles or so each year. If the cooling system has been maintained there should be no cooling issues.
you can see the V6 tubes at the fiero store. Or lay on your back along side the car and look just inside the bottom edge of the car. Stainless steel tubes, about an inch in diameter.
It doesn't matter what engine is in your Fiero. The way the coolant system works is there is a feed and a return. One side of the car feeds coolant from the engine to the radiator, the other side is the return where coolant comes back from the radiator to the engine.
You have to understand how this system is designed - the concept is actually very simple but the design is VERY fragile. Both the duke and the V6 are designed to run a bit hotter than most 'normal' engines do. You can be running 210-220 -ish, which would normally be a problem to watch but you can run that in a Fiero all day long and not damage anything. Later models particularly the 88's saw some very very slight design change in the underbody cooling system, but the overall system is the same on every Fiero. The tubes themselves are relatively small in diameter. It doesn't take very much at all to dent and bend them. You can do it simply by positioning a jack in the wrong spot and jacking it up for a second - it can cause a bend. The first thing I did when I bought my Formula was check the underbody coolant tubes. That was before I even popped the decklid. There are similarly designed mid-engined vehicles which have coolant tubes running directly in the middle of the vehicle which tends to be a better design, but remember than in the Fiero there is kinda a big gas tank there. It's not necessarily a flaw the Fiero has it's just the way it is designed.
It seriously is not at all that difficult to keep your Fiero cool. If you notice serious overheating problems (such as smoking decklid vents) then stop the car and fix the problem. It really isn't that much difficult when you think of for the design everything is relatively easy to check. Coolant tubes can be seen simply by lying down and looking at them, thermostat and fan can be easily check, even the water pump is relatively easy to check and diagnose. If you're overheating at high speed, then your water pump is probably bad 'cause it can push enough water/coolant to keep up. If it's overheating at idle or in traffic, then it's probably something I said in the 2nd prior sentence. If your temp gauge (guest-imator gauge) is bouncing around then you probably have an air bubble or your temp sender is going out. The point is if you take your time, be patient, and just think you can quickly solve excessive heat problems.
One thing a Fiero owner needs to look at is the cooling pipes that run from the front of the car to the back of the car. These tubes run down both sides of the car. It only takes 1 idiot to place a jack or lift in the wrong spot and the tubes get crushed. This in turn restricts the coolant flow and causes some overheating problems.
Thats why i'm afraid to take my car anywhere.. if they do crush them they will just deny it.
If you're overheating at high speed, then your water pump is probably bad 'cause it can push enough water/coolant to keep up.
Mine isn't overheating, but it runs warmer at speed. Less so with the lights up ( been thinking of adding vents ), Actually both of my GT's did that, but i was not the original owner on either so i never knew what it was like 'new' so i figured it was 'just the way it was'
Perhaps i should stick a new pump on.... That ought to be fun on V6...
That's another good point. Make sure your Fiero actually *IS* overheating and don't rely solely on the OEM gage. Fiero gages are notoriously bad.
What's the best way to do it, assuming your gage is garbage, short of hooking up a pc to your car? ( mine is pretty close to what the ECM says, so i assume its right )
What's the best way to do it, assuming your gage is garbage, short of hooking up a pc to your car? ( mine is pretty close to what the ECM says, so i assume its right )
Find a shop that has an I.R. pyrometer and check the operating temp. The thermostat housing seems like a good place to aim at. The block near the exhaust manifolds is going to read higher than the water temp. so don't take I.R. readings there.
Install a good aftermarket water temp. gage, (do the oil pressure and volt gages too while you're at it)
can someone show me a pic of the cooling pipes that are "crushable"
Here are some cooling parts I replaced as my Indy was having cooling issues
The coolant pipe on the right side was crushed because some idiot in the past jacked the car up by putting the jack in the wrong place
Any 25 year old car is going to have issues, but in my opinion the Fiero is prone to more cooling issues because of those long coolant pipes and the difficulty in bleeding the system and the generally higher engine bay temperatures due to lack of airflow.
If you have an air compressor and own a fiero then a tool worth investing in would be an "Airlift" cooling system filler.
I have one of these I use anytime I open a cooling system on any vehicle. Google it,and you'll understand. No air bubbles with this bad boy. I have yet to use it on my fiero,I was told it does not have a thermostat and I suspect it's because of an overheating issue. I have a thermo for it,just haven't dropped it in to see what happens. I'll get a chance to test drive the Airlift on it then,though I imagine it'll work as well as always. The one I have is a commercial version and cost me around $300,but there is a more generic one available that looks just as good for around $80-100. From the sounds of the constant overheat/air issue's you guy's seem to have I would strongly reccomend it.
If anyone is nearby me in Oklahoma,come by anytime and use it if you need.
Starting from the basic design differences: Rear fill design is backwards from 99% of other cars - if you fill it from the front, you will have cooling issues. Removable thermostat so air can easily be purged from the system - again is backwards from 99% of other cars. You can purge the air w/o the removable thermostat, but it takes much, much longer. Coolant tubes running along the rockers unlike 99% of other cars. These are routinely dented, kinked or crushed by lifting the car in the wrong location.
Age/Condition issues: Condenser/radiator fins - are they smashed over restricting airflow? Debris between the A/C condenser and Radiator - ever pull the radiator to remove anything stuck in there restricting flow (power wash the radiator and condenser at the same time)? Corrosion/gunk/stop leak in the radiator - never know how many cans of stop leak the previous owner sent into the system and now is restricting flow. Air dams and seal around the radiator - are they all still there and makinging a good seal? Air will follow the path of least resistance and w/o these sealing properly that path is around (not through) the radiator (this is a common cause on cars that heat up at highway speeds).
Mechanical/Maintenance Items: Coolant leaks - lower coolant levels will cause over temp conditions (if the temp drops qucikly after pulling away from a stop, you have a low coolant issue). Thermostat - is it working and allowing coolant to flow? Radiator Fan/Relays - are they working and does the fan have a shroud? Too much timing advance will raise engine temps V6 waterpumps had a habit of the impeller seperating from the shaft - this will cause an overheat condition.
Engine Swaps: Pretty much anything listed above Waterpump size/drive/routing - too small or too slow spinning waterpump will cause issues.
IP: Logged
08:05 AM
PFF
System Bot
fierosound Member
Posts: 15213 From: Calgary, Canada Registered: Nov 1999
I've NEVER had any problems with air trapped in the system. I just fill and go.
Proper fill procedure.
1. Uncap radiator and engine thermostat housing (pull thermostat). 2. Fill through thermostat housing until radiator is full. Cap radiator. 3. Fill through thermostat housing until engine is full. 4. Replace thermostat and thermostat housing cap. 5. Add some coolant to overflow bottle.
The system will "burp" itself and draw in coolant from the overflow bottle, so add more coolant to the bottle over the next few days keeping the level between the "Hot" and "Cold" markings.
IP: Logged
11:37 AM
Eclipse Member
Posts: 2040 From: Woodstock, Ontario Canada Registered: Jun 2004
I have a V6 on an engine stand which I am rebuilding. When I removed the heads, I found that almost all of the coolant passages between the block and heads were crusted and blocked with hard deposits. Once I cleaned them all out, I was amazed at how much blockage there seemed to be. Would that not lead to issues? I wonder how many cars are in that situation. Is there anything good out there to clean that out without dissassembling the motor?
See all of those holes around each cylinder? Most were blocked solid...
------------------ Jay Brintnell Southern Ontario Fiero Association and the Ontario Pontiac Club
Learning is not compulsory. Neither is survival. - W. Edwards Deming
Thought I would post a pic of the Airlift i've got. I'll take some pics and maybe a quick how to video soon. I plan to drain,flush and refill the cooling system.
There is some radiator flush cleaner you can get at autozone for a few bucks,it's the same stuff we use at the dealership and same procedure (of course our's says "motorcraft"). There are commercial flush machines for coolant,but honestly there is not much difference I believe from using the machine and the flush chemical.
Basically drain the entire system and refill with water (pour in the flush before water). Idle car for 20m (I idle for longer usually) then drain. Refill with straight water,run for 20m and drain. Refill and burp system-send on it's way.
I get a bit more in depth with my own cars,but usually just keep it in longer and flush with clean water more. I've been known to put some B12 or seafoam in my own cars cooling system with the water for a quick runthrough. Never know what will happen though,you could break off a big peice and clog something.
Here is my airlift I use to pull a vacuum on the system and backfill it.
IP: Logged
01:16 PM
30+mpg Member
Posts: 4061 From: Russellville, AR Registered: Feb 2002
After filling at the thermostat housing, remove the wire from the nearby temp sensor in the head.
Unscrew temp sensor with a 21 mm wrench till you see bubbles appearing at the threads.
Continue until bubbles are replaced by coolant flow only.
Retighten sensor and reattach wiring.
This will remove the trapped air bubble in the head. It helps if the left side of the car and engine head is slightly higher than the right side. Who needs another cracked Duke head anyway?
I'm sure there are several different tried and proven ways to fill and burp the system, but 1 thing is very important to remember. FLUSH THE SYSTEM! it'll cost you about $20 to $25 to drain, clean, flush and refill the system. BUT if you don't, terrible things can happen that will cost much MUCH more to fix. This may be somewhat off topic but i always bring my F-150 to the dealer for service and apparently at the 50k or 60k mark when i paid them to flush the system they didn't because on Christmas eve, at about 80k my heater core rotted through turning my truck into a fog machine. Ford quoted me over a grand to replace the heater core, merry Christmas! Needless to say i did it myself for less than a hundred bucks. BUT the point is, spend a few bucks now ( i know it's sometimes hard since everything is working fine) but DO IT NOW, flush, clean, refill. better $25 on a sunny Saturday afternoon when you have the time then to be forced to do it later. Now i do it EVERY year. TRUST ME! this is one time where if it aint broke, don't fix it is total BS!
IP: Logged
07:02 PM
DLCLK87GT Member
Posts: 2717 From: South Jersey, USA Registered: Feb 2009
I believe it ran somewhere between $250-350-i've had it awhile and can't remember exactly.
I did a search to see if it was a practical tool to mention on here and found perfectly suitable versions by the same company for $80-100 though. I know the overheating/airlock issues with the 3.1/3.4 motors as I have some experience in them,and having owned this tool and a car with those motors I would definately call it an essential tool for the home mechanic that does all his own work(and owns a 2.8/3.1/3.4 engine).
[This message has been edited by DefEddie (edited 08-10-2009).]
IP: Logged
09:41 PM
Aug 11th, 2009
sjmaye Member
Posts: 2468 From: Hendersonville, TN USA Registered: Jun 2003
I agree with FieroSound and the rest. I have had no issues with overheating with either of my Fieros. One of which I have had since 1993. The cooling system is unique, The only thing I can think of that I believe is critical is getting the air out of the system. It sounds pretty complicated, but in truth I found that easy as well. Many posts on how to do it.
I think something that would be helpful is a step-by-step troubleshooting guide for overheating so people could more easily narrow down where the overheating is coming from. Is it air in the system, crimped fluid line. bad thermostat.....?
merry Christmas! Needless to say i did it myself for less than a hundred bucks. BUT the point is, spend a few bucks now ( i know it's sometimes hard since everything is working fine) but DO IT NOW, flush, clean, refill. better $25 on a sunny Saturday afternoon when you have the time then to be forced to do it later. Now i do it EVERY year. TRUST ME! this is one time where if it aint broke, don't fix it is total BS!
