Another thing I suggest for any V6 is Rodney Dickman's low temp fan switch and 180 thermostat. It is a much better setup than stock. I don't know what GM was thinking! It's some of the best money you can spend on your V6 Fiero in my opinion. Don't go for the 160 setup. That is too low.
Just some quick checks: Turn on the A/C and leave it on, this causes the fan to run all the time. If that solves it then the thermal switch is probably bad. If that doesn't solve it see if revving the engine helps, leave it in a lower gear when driving, but don't over-rev it. If that helps, then the problem is either a crushed cooling tube, faulty water pump, or faulty thermostat. The reasoning is that flow is related to RPM and if you need more RPM to get sufficient flow then there's a blockage somewhere. Also, have the system pressure checked, any radiator shop can do this easily. The system has to hold 15 psi, and if it won't you need to find the leak or replace the front radiator cap.
Thanks everyone, I will be printing this and have the next mechanic try these solutions. I always manage to leave something out when I post. I did replace the radiator cap, and the air condition hasnt worked since I got the car (don't know why yet, didn't have the funds and the time to get that looked at quite yet.
thanks for all the suggestions, and the welcome.
Gecko
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11:57 PM
Aug 29th, 2004
Songman Member
Posts: 12496 From: Nashville, TN Registered: Aug 2000
From reading this and other things, I was able to find out a little bit more ( I think). I did the suggestion of turning on the air conditioning, because I realized that my gf does that when she drove it, and it didn't overheat on her as much. Well that seems to work, the temp guage didn't go to high doing that. When I came to a stop I noticed it would start to go up a lil, and that by highering the RPM's it would go back down, same with driving in a lower gear. This was starting to make me very happy knowing that I could now control this issue. I managed to drive around town for about 13miles without coming close to overheating. Then suddenly the guage shot up and I could barely keep it out of the red using the same techniques, I was driving in circles basically so I was able to get it home, opened it up and took a look and noticed the Cap for the Engine Oil was now missing, it was kinda crappy anyways so I think it must have came loose and fell off from hitting a bump or something. (I had checked the oil last night and know I put the cap on then) so it had to just happen now, and I think that is what caused it to overheat.
Does this sound correct?
thanks for all the help, the fact that I got 13miles with no problem, is a very good sign in my opinion.
Gecko
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02:03 AM
madcurl Member
Posts: 21401 From: In a Van down by the Kern River Registered: Jul 2003
Sounds like you still have a bubble or air in the system. Let the car get hot (190-200 degrees), turn the motor off and bleed some of the air out? Be very careful while doing this...it can burn you so use gloves and face shield. If the radiator cap has been checked out and is okay, just turn the radiator cap and lessen for hissing noises. Hopefully the should exscape.
I've done this on my N* but it's pressurized system using the resouvor in the back to bleed off excess air or bubble.
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02:32 AM
2000RagTop Member
Posts: 3999 From: Sussex, (Milwaukee) Wi. USA, Earth Registered: Jun 2003
The thirmistat may be stuck even though it may be fairly new (I pitched my thirmistat months ago,but would come in handy in the winter time).Look for water in the oil (milkey brown),you may have a blow head gasket.You may have the wrong kind of radiator cap,(I think the lever ones are the wrong kind???).Also make sure you have plenty of oil.
if you are looking for a temporary fix on your fan, you can ground the fan switch so that everytime your engine is on, your fan is on...........the fan switch is on the front side of the engine (where the battery is) and you can ground it by taking some regular wire and hook it up to the wire that connects to the fan switch and take the other end of the wire and ground it anywhere........that should be a temporary fix while you get your car checked out....... ill try to find some pics to help you locate the switch if you want..... -Roy
------------------ I own an original yellow 1988 Pontiac Fiero GT, (wingless, currently purple) ....This is.....Driving Exitement! Matching numbers GT #17889 of 26,402 made in 1988, 1of 241 yellow GT's
check the coolant pipes under the car... read that article in my cave. Even a small bent can make enough restiction to make the temperature jump. V6 can be even more picky about this than the L4.
If people go with the low temp fan switch, I recomend the higher temp one Rodney has. The idea is that the fan shouldn't run all the time. You may want it to come on in heavy traffic but shut off when there is enough air moving. That cuts load on the alternator and helps fuel mileage. V6 cars tend to need all the help they can get in that department.
In many cases, the low temp fan switch is just masking problems in the cooling system. Let go, these problems can continue to degrade the system and make the car overheat even with the fan on.
When a mechanic says a radiator is ok... The first thing I have to wonder is how did they check it. If they didn't empty it and put something down there so they can inspect the bottom end, then you could have allot more blockage than you think. The bottom can have a huge amount of blockage and still look nice up top. Even visually inspecting all the way to the bottom of the right tank may not uncover blockage... The left tank may be full of rust and other crud from the engine that has settled out. No way to see that without pulling the hoses.
------------------ The only thing George Orwell got wrong was the year.
If your water pump is new , please check the lip under your front nose ( excuse me but I don`t know the english name of that part , but I think other member know ) . Maybe this lip is broken or somebody took away . Mostly that is the point engine goes hot ! D.Rohm
The thirmistat may be stuck even though it may be fairly new (I pitched my thirmistat months ago,but would come in handy in the winter time).Look for water in the oil (milkey brown),you may have a blow head gasket.You may have the wrong kind of radiator cap,(I think the lever ones are the wrong kind???).Also make sure you have plenty of oil.
i was thinking head gasket too, because my 2.8 (may it RIP) had a blown head gasket and I had some of the same symptoms like having to consistently rev, etc. (even with all the bar's leak I could find). Trouble is replacing a head gasket can potentially cause other problems (ie. throwing a rod like mine did). Pray it's one of the other diagnoses, otherwise you might be looking forward to an engine swap down the road!!!
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02:47 PM
jscott1 Member
Posts: 21676 From: Houston, TX , USA Registered: Dec 2001
If this is a car you intend to keep for a while, then I would suggest just replacing the radiator. It's about $100 and a few hours and most cooling problems are solved. Even if that wasn't the root cause, it's probably 18 years old and ready to start leaking on you anyway.
If that doesn't fix the problem and you can verify no crushed coolant pipe then I would start looking at the engine. I would start with the water pump. They are a pain to replace but they are relatively cheap. I would replace that and see what happens.
If you are still overheating then you have probably go a bad head gasket and no amount of cooling will fix that problem. The heads will have to come off. Let's hope it doesn't come to that.
Jonathan
------------------ 1988 GT (Firebird Interior),1988 Coupe (Daily Driver), 1985 SE (Project Car), 1985 Coupe (parts car), Firebird Interior Installation Website
Here is how my day is going.......would you believe nobody in the area seems to carry an Oil Cap for my car........geez the 6 cylinder Fiero must be really exotic lol
It's sunday and the salvage yards don't seem to be open, and i bet if they were it would be a nightmare trying to find one that actually has a 6 cylinder fiero in it.
Anyone want to bring me an oil cap today? lol
By the way, does anyone have any recommendations for mechanics in the NJ area that are familiar with working on Fieros?
By the way, does anyone have any recommendations for mechanics in the NJ area that are familiar with working on Fieros?
thanks Gecko
Not sure where in Jersey you are, but you might try Fiero Jon...here's some info I copied from another website...
Fiero Jon's Restorations, Service, and Parts is located about 1-1/2 hours south of NYC. 1 hour from Philly, and 30 minutes north of Atlantic City. www.fierojon.com
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03:25 PM
Songman Member
Posts: 12496 From: Nashville, TN Registered: Aug 2000
If this is a car you intend to keep for a while, then I would suggest just replacing the radiator. It's about $100 and a few hours and most cooling problems are solved. Even if that wasn't the root cause, it's probably 18 years old and ready to start leaking on you anyway.
If that doesn't fix the problem and you can verify no crushed coolant pipe then I would start looking at the engine. I would start with the water pump. They are a pain to replace but they are relatively cheap. I would replace that and see what happens.
If you are still overheating then you have probably go a bad head gasket and no amount of cooling will fix that problem. The heads will have to come off. Let's hope it doesn't come to that.
Jonathan
Once you verify that your hoses are not kinked or soggy, that your coolant has no trapped air in the system, and that you fan works properly; I would go with the suggestion to replace the radiator. Your radiator is 17 years old and may be partilally clogged. If you suspect a head gasket; usually a compression check tells the story. However, before you buy a new radiator, replace the thermostat w a 180* unit. I've experienced sticking themostats several times before so I know it does happen.
One other possibility is that your waterpump has a plastic impeller. Once they get hot, the impeller slips on the shaft, and doesn't pump as efficiently as it should. A good radiator shop should be able to tell if your pump is working properly...if it isn't, you need to replace it with a pump that has a METAL impeller. Just one more thing to look for, along with all the other excellent advice already given above.
thanks again for the suggestions. I will probably replace the radiator simply because its old, and it won't cost to much. I can't afford to buy a new fiero so I don't mind replacing things that. My mechanical skills are ......well NONE. So I am printing this and having whichever mechanic try out the suggestions mentioned, or probably that Fiero Jon, if he isn't to busy and I can get the car to him (about 90 highway miles from me, so should only take about an hour to get there) LOL, provided I get that oil cap and get the car running. I was thinking the same thing it's probably the same engine as the other 2.8's firebirds and such, but I was so tired at that point, I gave up and went to bed. I tend to keep weird hours so now I am fully rested and have to wait about 8hrs before I can do anything oh well.
btw, if I get a few pictures can someone combine them into one of those fancy signatures for me? thanks again Gecko
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12:31 AM
Aug 31st, 2004
texasfiero Member
Posts: 4674 From: Houston, TX USA Registered: Jun 2003
Originally posted by Gecko: Hello, I have an 87 GT 6cyl 5 speed. It overheats in town, or when stopped in traffic and such, however it runs just fine on the highway. I have seen the fan working, a mechanic told me the radiator is fine, the thermostat was replaced,the water pump was replaced. Gecko
I had a very similar problem on an '86GT which I fought for two summers. It was very sporadic and I could NEVER anticipate an over heat. I had decided to pull the water pump and check for the plastic impeller when someone suggested checking the a/c controls. What I discovered was a burned trace on the a/c head (to pin H) . This circuit should ground the fan relay and force the fan on without waiting for the a/c pressure switch or the coolant temp switch. On the road and under certain conditions (?) the car would run fine, then suddenly overheat. Since the fan was not forced on by the a/c, the engine had to be very hot to get the fan on and in hot temps it would overheat before the fan could bring collant temps down. I jumped the open with a small section of wire and never had the problem again.
