I am about to go in to see just why my SBC is overheating. It sits at 180 degrees for a good 8 or 9 minutes, then creeps up to 230 or so before I shut it down. It doesn't matter if it is out on the road or idling. I am looking for suggestions.

Here is what I am doing this weekend to solve it:
1- replace carb gasket in case it is leaking
2- pull thermostat to see if it is slowing the coolant from the electric water pump
3- adjust timing - which is tough because I don't think previous owner (Yons) installed a timing mark. Perhaps this should be done first?

FYI-
The electric fan is on with the key - and it is a large one sitting behind the 4-core Nova radiator
Electric water pump comes on with the key, too, and coolant is moving because the return line at the engine heats up when the thermostat opens at 180 degrees
My heater hose is just a useless line right now because Yons pulled out the entire heating/AC system to put in a sub. I'll check, but I assume that the ends of the heater hoses are connected. I don't think that is effecting my temp reading from the sensor on the intake.
I just replaced the front and rear radiator caps with no change to the temp problem.
I jacked up the rear and filled it with coolant - then ran it -filled it again, and repeated. After driving it around, I put another ounce or two in, but it did not need much. I don't think there is air in the system at all.

Anyway - if you have another suggestion, let me know! This and the leaking axle boot are the only thing keeping me from driving it to work.

Thanks!

If there is no air in the line maybe either a crushed coolant tube or a plugged radiator. Or maybe a bad water pump.

Feel all the hoses and pipes to see if they are all warm. You might have a hose or hoses in the wrong places. Also open the heater valve. My 383 with 160* stat never got even half way up the gauge unless i let it idle for an hour or so in traffic. I used the stock 4 cyl radiator and fan with an auto. If all the hoses are warm to touch, its prob flowing OK. Next suspect would be timing advanced too far. Im assuming you have a new or operating water pump (feeling the hoses would verify that). You could also have the wrong water pump. Some bolt on fine, but impeller turns the opposite direction...seen that on a few GM cars.

[This message has been edited by rogergarrison (edited 11-16-2006).]

quote Originally posted by rogergarrison:Feel all the hoses and pipes to see if they are all warm. You might have a hose or hoses in the wrong places. Also open the heater valve. My 383 with 160* stat never got even half way up the gauge unless i let it idle for an hour or so in traffic. I used the stock 4 cyl radiator and fan with an auto. If all the hoses are warm to touch, its prob flowing OK. Next suspect would be timing advanced too far. Im assuming you have a new or operating water pump (feeling the hoses would verify that). You could also have the wrong water pump. Some bolt on fine, but impeller turns the opposite direction...seen that on a few GM cars.

Thanks for the help you guys!

Say, does the rotor turn clockwise? I may retart the timing a little bit to see if that helps until I can come up with some type of timing mark.

I'll take a look at the heater lines, but I think that since all heating parts were removed, the hoses just connect under the hood somewhere. I'll check - and feel all the lines to make sure. Also, who knows what direction the pump is flowing as Yons put in there - and he didn't even know what engine he put in there.

My hoses are setup like this
The hose going to the intake is ran over to the drivers side of the car. The hose coming from the water pump is down the passanger side. If its ran backwards it could be sucking air at the radiator. I dont have any heater hooked up and it still runs cool, it wont go over 180 with the fan on even when I beat on it.
Good luck

[This message has been edited by Jake_Dragon (edited 11-16-2006).]

Saxman,
Sounds very close to the issues that I was experiencing with my recently rebuilt SBC. I had tried 3 different electric pump brands, with no luck. I finally got the got the problem solved by removing the thermostat, installing a lever type radiator cap & bleeding air from the system MANY times. I am running the heater and all lines now get equally hot. I'm still running over 220-230F, which is hotter than it used to run. I recently sent a inquiry to V8 Archie with a request for pricing on his HD radiator, since I am running the stock Fiero unit, without A/C. This car has run with the same combo for several years, without issue. It would rarely exceed 220F, even in 90+ ambient air temperatures. The only difference is a newly rebuilt (tight) engine, which may be generating higher coolant temperatures, in my case.
Please keep us posted on your solution(s).

It has been a while since I had my 88 with a 305 TPI auto, but I had a problem with the correct Rad caps. The one at the engine was 21lbs., (highest I could find), and the front one was 17lbs. with the original overflow tank. You have to plug the rear overflow tube. Not just to prevent it from releasing pressure, but to keep it from sucking air in when the coolant cools, (contracts).
Good Luck,
Kevin

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85 Fiero-based ASPP GT-40 MarkII. 3800 S/C, Auto, Held suspension all around with 2" drop spindles and sport fr. end. RCC bump-steer correction. Mr. Mike's interior.

My CSI Water Pump started leaking and eventually quit working. Seems the seals in the old pumps are a weak point that CSI has since upgraded. Anyway when it did go out it would start up and pump for a bit then quit. I also had this happen when the splice I used to power the pump couldn't handle the amps. Apparently the amperage will cause weak connections to heat up then disconnect. The hoses will all be warm when this happens so checking flow can't be checked by feeling the heat from the pipes. What clued me in to what was happening was the absense of sound from the pump. And by the way after a cooldown period it would go back to working. The splice problem and the seal problem give almost the same symtoms.

quote Originally posted by Butter:My CSI Water Pump started leaking and eventually quit working. Seems the seals in the old pumps are a weak point that CSI has since upgraded. Anyway when it did go out it would start up and pump for a bit then quit. I also had this happen when the splice I used to power the pump couldn't handle the amps. Apparently the amperage will cause weak connections to heat up then disconnect. The hoses will all be warm when this happens so checking flow can't be checked by feeling the heat from the pipes. What clued me in to what was happening was the absense of sound from the pump. And by the way after a cooldown period it would go back to working. The splice problem and the seal problem give almost the same symtoms.

I'll check the wiring over, too, Butter. I guess it would be good to have one of those listening tools to see if the pump is still going as strong when things start to heat up since I won't be able to tell by feel. I don't have a leak, so the seals must be OK. It has a Nova 4-core fadiator, so it should be cooling enough up front. Of course, it could be bad on the inside.

Also, like Jake mentioned, I can see that my "to-radiator" line goes under the driver's side and the "return" come under the passenger's side, so that is OK. I haven't put an eye to check for crushed lines. I'll get some time out in the garage this weekend. Friggin migraine headaches and sick kids have been taking up all my time around the house this week.

Boominator, your car runs around 230 without the thermostat? That sounds high (according to most), but my '06 Trailblazer runs at 210 all day long, so it may not be too bad.

GT40 Kit 3.8 SC - I just replaced the front cap with a stock Fiero part - and the rear has a plug in the overflow outlet, so at least they are all new. Again, there are no leaks of coolant.

Thanks again for the help (and +'s to you)

My car runs 170-200°F with e-pump and stock V6 radiator here in south FL. Every time I had heating issues it has been improper burping. Some times I had to lower the car, rise it again, lower it and rise again to get all air out. Very annoying as I thought something else was wrong every time. Even happened when I did my last 3.4 swap. I would check that one more time just in case.

quote Originally posted by Saxman: ...I just replaced the front cap with a stock Fiero part...

If you got the cap that Stant lists as a replacement for the Fiero, you have the wrong cap.

Read this article from TheOgre's cave...
http://home.comcast.net/~fierocave/coolcaps.htm

Main page at:
http://home.comcast.net/~fierocave/

Im not sure, but I think water pumps for later model v8s turn the opposite direction from older ones due to using serpentine belts. On mine I used a 57 chevy pickup water pump mounted upside down if I remember correctly. My engine was an 88 Corvette.

[This message has been edited by rogergarrison (edited 11-17-2006).]

Raydar,
Thanks for posting the link regarding the radiator caps. I have the WRONG one (vented) based on the posted information. I'll pick up a non-vented #10230 Stant brand cap and burp the system again.
Boomer

Yup - I have a vented rad cap. TIme to hit the stores again...

I guess I might as well replace the one on the rear, too. I hope that does it!

quote Originally posted by Saxman: I'll check the wiring over, too, Butter. I guess it would be good to have one of those listening tools to see if the pump is still going as strong when things start to heat up since I won't be able to tell by feel. I don't have a leak, so the seals must be OK. It has a Nova 4-core fadiator, so it should be cooling enough up front. Of course, it could be bad on the inside.

I never noticed the leak on my pump till it give up. It just didn't have to leak much to take out the brushes in the motor I guess. There was four brushes on my CSI pump. If 1 or 2 opposing brushes give up your motor loses half its power. It may still work just not very well.

On your radiator pull the cap off and look into the radiator to check the flow while running and NOT HOT of coarse. If the flues are flowing out gently the radiator has open flues or are in good shape. If you see them squirting out the flues need to be rodded. Had a good friend that was once a radiator repair man tell me that and it has been 100% correct for me so far.

OK - I got the new caps. They go on tomorrow, then I'll re-burp the system and fire her up again. If that doesn't help, then the T-stat comes out (temporarily) to see if that is the problem. I'll keep an ear on the water pump to make sure it is not shutting down on me, too.

More to come...

With out the heater hooked up you wont flow any water when its cold. I dont see how you could get all of the air out of the system with the thermostat still in the car. I think even Archie says to remove the stat until you have all of the air worked out. I know one thing, I will never run another stat with out a small hole drilled in it. You get an air pocket under the stat and it wont open, then you loose your motor. I think thats what happened to my SE

The best way to get the air out of the Fiero's cooling system is to use the vacuum tool sold by Snap-on...the cooling system must be partially drained, but I never had an issue on any cars...and Audi's are worse to bleed out than the Fiero. I also run an electric water pump, 160 degree t-stat, and four core radiator from PISA with OE Mercedes Benz antifreeze in my V8 Fiero.
Dave

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quote Originally posted by Jake_Dragon:With out the heater hooked up you wont flow any water when its cold. I dont see how you could get all of the air out of the system with the thermostat still in the car. I think even Archie says to remove the stat until you have all of the air worked out. I know one thing, I will never run another stat with out a small hole drilled in it. You get an air pocket under the stat and it wont open, then you loose your motor. I think thats what happened to my SE

Mine is set up so that the thermostat can not come out without the entire cap/hose being taken off - thus draing the system a little bit - defeating the purpose. In the pic below, you can see the thermostat sits below the t-cap and that purple block, which also feeds the coolant out to the radiator on the side you can't see. I'll have to check, but I don't think there is space for the thermostat directly below the cap - and I wouldn't be able to fill it with one there, anyway.



I put the correct front cap on and it didn't make much of a difference, The CSR cap over the thermostat looks nice and since there is no overflow setup (and no leaking at all) I plan to leave it there. The temp seemed to rise slower, but still went up to 235 before I shut her down. I adjusted the distributor clockwise (thinking that will give it less advance if any) and it did not help either. It still takes at least 10 minutes to get too hot. On the first startup, the temp went to 210, then down to 180 for a long time before slowly climbing again.

When she cools off, I will take the t-stat out and see if that makes a difference. While it is out, I'll boil it to see how far it opens and also drill a small hole just in case it does work and I actually have a bubble to work out of the system...

Thanks, bmwguru - I appreciate the help, too!

Well, there WAS a 160 thermostat in there, which does not explain why it went to 180 so quick. It did not open well (on the oven) until around 175 or so, but it opened all the way. I also tested the new 180 degree t-stat and it opened fine at 180.

Should I still try the car without any t-stat to see if that is part of the problem?

Also, do I need to let the gasket sealer set for a while before starting the car or can I start it immediately?

My V-8 Cooling experience. I tried three different stats. 160 180 195. None of which worked like i wanted. My overheating only occured on highway driving. The setup i use now is a gutted t-stat, used as a restrictor. It runs around 180 in city stop and go traffic and will hang around 195 highway driving. With all that said the biggest thing that helped was the rubber air damn under the front of the car. The old one was cracked and I'm sure on the highway would bend backwards not directing air up to the radiator. With the new one on, highway temps stayed lower in a good range. Also since i run the belt drive system, in city driving, less rpm, less flow, I believe gives the water more time to cool in the radiator equalying lower temps.
Just how it works in my mind!
Good Luck
Gary

KGDINC, I am worried about sitting in traffic since I want to use this car to make my drive to work bearable. Problem is - the is a lot of stop and go traffic between here and DC, so if I have to rely on the air dam to cool the car, I will be stranded.

I noticed that the 160 degree Tstat that was in there took a very long time to close while the new 180 degree Tstat closed up within 10-15 seconds. I wonder if that causes any of my problems. Perhaps the coolant could not stay in the radiator long enough to cool off because the Tstat didn't close quick enough to keep it there?

I think I should go ahead and put in the new Tstat (with a small drilled hole) and see how things go. If it is fine, then I saved myself another afternoon of putting a Tstat back in there. If it does not work, I will remove the Tstat completely...

So frustrating!

One other thing I should mention is that less rubber hose is better! I ran the water pump upside down so the bottom hose goes towards the front of the car. The t-stat has a three inch extender and swivels nd I put a 13lb cap there and a 22lb cap on the radiator. The cap on the engine is the highest point, so that is where the air will wind up. My overflow bottle is mounted o the original fuel pump relay bracket under the left grille. I use the MB coolant because it is very similar to the standard green, but it has some additives for the aluminum radiator...I also have about 30 gallons of it in my shop at a time, so it's easy to come by. I also like the yellow color...it's a bit different.
Also, about less rubber hose. I purchased 1 1/2" J-bends from summit racing (used for headers), cut and welded them, ground the welds flush and painted them flat black...and that is my cooling system plumbing. I used about 5 J-bends and they hold pressure with ease. I set up the rear trunk blower to blow air onto the pipe as well. I'm not sure if it makes a difference, but I figured as long as it was there.

you can see towards the rear of the engine the black pipe. It extends from the top of the t-stat to just past the slave cylinder. I also have one up front by the radiator and the water pump pipe runs through the body with a heat shield around it sitting behind the passenger side intake scoop.
Dave

Saxman, I'm just going to throw a few things out here based on my experience with another "heat mother" of an engine. I had a supercharged rotary RX7 motor installed (about 305 h.p. at the crank), rear engine, in my kit. Cooling pipes to the front similar to a Fiero. When I began the planning stages of my car guys kept telling me, "Oh, that's going to run sooo... hot you'll never keep it cool." A rotary's exhaust can even be between 1600 to 2000. Things I did before ever even starting the thing up was make heat shielding for almost every critical area of the motor. I used two layers of exhaust high temp. wrap from the head pipes all the way out to the muffler. I installed a carb heat shield and phenolic spacer under the carb. I also installed a 10 inch oil cooler fan which served the dual purpose of cooling the cooler and exhausting hot air from the engine bay. I built my own cold air box for the intake to pick up "truly cold air." A restrictor was placed in the feed radiator hose about a foot from the radiator. I was told by several radiator gurus that this was important to pressurize the liquid as it went through the radiator and reduce air pockets and cavitation. I also ran Redline's water wetter which again reduces cavitation.
I guess my point here is you've inherited another guys "design" work on this cooling system. It may take a combination of things to get this rascal cooled down like you want. By the way, my car never ran past 210 degrees. That was even after a 146 m.p.h. run shifting at 9500 r.p.m through ever gear on an 87 degree day.

AAAAAAAAARRRRGGGGGGGGGGGGGGHHHHHHHHHHHHHHHHH! Hear that sound? You are hearing Saxman pull every lock of hair out of his head! Son of a... I mean SON OF A...

It seems that someone (Yons) forgot that the fan will turn the wrong way if the wires are switched - which also means that I am dumb for not thinking of it sooner. JEEZ!! (Insert every sweat word you have ever heard here - and some!)

I got my first clue when the shopping bag from my trip to the auto parts store (for new radiator caps) started blowing away from the car while it was running. My mind said, "You friggin' idiot, what is wrong with you!" I knew it was going the wrong way before I even check it. UNBELIEVABLE! (OK - it's believable - I am the gullable Saxman - buyer of all cars with big problems - after all)

I will take her for a run if my wife gets back soon - or tomorrow morning and report back, but I think all is well now. (Insert additional cuss words here - and feel free to add them for me)

Anyway, the temp went up to 180 degrees and stayed there for about 15 minutes.

quote Originally posted by Saxman: AAAAAAAAARRRRGGGGGGGGGGGGGGHHHHHHHHHHHHHHHHH! Hear that sound? You are hearing Saxman pull every lock of hair out of his head! Son of a... I mean SON OF A... It seems that someone (Yons) forgot that the fan will turn the wrong way if the wires are switched - which also means that I am dumb for not thinking of it sooner. JEEZ!! (Insert every sweat word you have ever heard here - and some!) I got my first clue when the shopping bag from my trip to the auto parts store (for new radiator caps) started blowing away from the car while it was running. My mind said, "You friggin' idiot, what is wrong with you!" I knew it was going the wrong way before I even check it. UNBELIEVABLE! (OK - it's believable - I am the gullable Saxman - buyer of all cars with big problems - after all) I will take her for a run if my wife gets back soon - or tomorrow morning and report back, but I think all is well now. (Insert additional cuss words here - and feel free to add them for me) Anyway, the temp went up to 180 degrees and stayed there for about 15 minutes.

One of those times, where you feel totally upset at yourself, and yet totally elated at the same time!
Don't you just love working on cars?!

Kevin

Like I said you inherited another guys crappy engineering! Sure, you may have lost a few hairs out of that head, but hey, it'll grow back.
Glad you figured it out.

quote Originally posted by Darrelk:Like I said you inherited another guys crappy engineering! Sure, you may have lost a few hairs out of that head, but hey, it'll grow back. Glad you figured it out.

Do you have a link to the kit you are talking about? It sounds interesting!

Yeah - Lambo Nut - working on these cars is great therapy. I'll learn to be the most patient person around if I keep buying cars like these!

Just wondering if these would help out insted of a thermostat.

http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_26911_-1_10129

Yeah, those restrictors work fine. Mine was even simpler than that. Just a PVC fitting reducer put in line right before the radiator.
Saxman, as for that kit, it is no longer made. It was a Bremen Industries manufactured Sebring which is similar to the Sterlings still sold by Solid Sterling out west. Here are a few pics. of the car...
http://s66.photobucket.com/albums/h251/DarrelK/?action=view¤t=0137.jpg
http://s66.photobucket.com/albums/h251/DarrelK/?action=view¤t=0132.jpg
http://s66.photobucket.com/albums/h251/DarrelK/?action=view¤t=0130.jpg

Nice! I assume the entire car is part of the kit? It doesn't look like it was built on any existing frame.

Lots of looks in that car, I bet!

Actually those body kits fit on a type I VW Beetle frame. What was different about the way they mounted is that the VW pans were trimmed away since the Sebring already had it's own fiberglas drop pans molded into the body. It was a very slick kit to assemble. Two guys could put together a Stage III prewired kit in a long weekend. Yep, I used to show it quite a bit, it did very well. Under 2000 pound curb weight too. It used to scream with that rotary set-up. Was a perky performer even when I used to have a 2.8 v/6 in it.

I put the fan blade on backwards for my rear scoop. Turned the right way, but didnt push much air. I was lucky though, as I realized it once I tested it. Glad to hear the car's fixed expect to see it sunday!

quote Originally posted by Francis T:I put the fan blade on backwards for my rear scoop. Turned the right way, but didnt push much air. I was lucky though, as I realized it once I tested it. Glad to hear the car's fixed expect to see it sunday!

I'm not sure about Sunday yet. My new axle arrives tomorrow, but Sunday may be too soon to drive 1 1/2 hours to start the cruise. I haven't got the kitchen-pass yet, either.

Maybe you guys can make it up to MIR for a race before they close (if they haven't closed already). It's impressive seeing Lildevil and Soulcrusher run their 3800SC's!