Hey guys, my IROC overheats so often, i gave up on it a while ago, and just replaced the radiator, with an all aluminum, and even then, it stayed
hot.

I ended up taking out my 160* thermostat, and wiring my fan to be on always. that, and a bottle of water wetter (overkill?)

anyway, my engine is running damn cold now, not even sure how cold exactly, with the stock gauge. is this hurting me bad? i know my ecu has
thrown me some codes before, and i have heard that running too cold will screw with the ECU. any suggestions? the reason i took the
thermostat out, was because it never kicked on the fan, or even opened up. same with the old one. i just got sick of having to pull over because
i was hitting like 260-280+.

Any experience or technical knowledge you guys can give me would be great!

 

first thing i wondered is your gauge accurate and did you have air in the head next to the temp sender?

------------------
ICON Motorsports

1st & 3rd

 

Well if you said your thermo wasn't even opening up then thats why you were overheating. I have seen it before where you have two bad parts in a row right off the shelf like a thermostat. So It still could be that. If you don't have a thermo, you engine will run real cold... under 100 degree if you have your fan always on like you said you have. Also the thermostat doesn't get kicked on by the thermostat... It is controlled by a second temp sender (not the one for the guage) It should be in the head and sends a signal to the ECM and turns the fan on when it reaches a certain temp. So I think if you put in a good thermostat and wire your fan back the way it should be you will be fine.

 

put a working thermo back in, check your air dam, and go read the tech article on making your fans come on at a decent temp. I used the adjustable fan relay, car has yet to hit 200*, and usually runs at about 175 to 190
oh yah, and make sure you get the air out of the system after you change the thermo
------------------
90 IROC 5.7l (L98)
ram air, K&N's, air foil,Flows

LIKE A ROC

[This message has been edited by Mo (edited January 25, 2001).]

 

Well one last thing I would replace is the radiator cap. This is what went bad on my car and I ended up replacing the radiator, water pump with a edelbrock AL high flow pump and putting in an adjustable fan relay. Then I found out it was the radiator cap from a friend!
Now summer driving with the AC on in the city on a 90* day I don't go past 210*. An this is with a 180* stat.
Good Luck!

 

I've got a 160º stat and my car runs just under the first line on the gauge all the time, and gets just over it in traffic. I was going to say check between your radiator and a/c condensor, because stuff gets in there and blocks the air passage. But you said you already replaced the radiator. If nothing else works then you might have a cracked block or heads.

------------------
West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Remember, the fan only cools when you're not moving. When your doin' 30, your fan is useless.

------------------
'82 Firebird, dead stock, 9 bolt disc rear, over 200,000 miles and still going strong, more to come...
http://www.spinfrenzy.com/stingerssx...easures.html#4

 

Cool, wasn't too sure how cold my car should run. As for the fan, my car rapidly verheats quickly, no matter my speed, with it off. i am hesitant to wire everythign back, because i hate having to constantly check the temp gauge, and then pull over and shut off my car, and wire the fan back up if it doesnt work. no fun.

I just need a crate ZZ4, with a BELT driven fan. oh the sweetness of it all!

 

Not to be a *****, but has it occured to you that something is obviously out of whack with your car. You don't hear everybvody else on these boards with the same car as you complaining that they constantly overheat and had to rig everything cooling system related till it would stop. Even among heavily modifed cars/blown cars/400 block cars.
What that should tell you is something is obviously wrong. Replacing the radiator when it gets old is a nice first step if it looks like it's getting clogged. But what about the radiator cap (as was previously mentioned) i've seen the weirdest colling system problems imaginable caused by a bad rad. cap. So often in fact that it's the first part i replace on a car that i get, just as cheap insurance.
As for the no-thermostat business. Thats a bad idea. I'm surprised you don't still overheat with it out. Without some form of restriction in the water neck, the coolant moves too fast to effectively pull heat from the engine, or let heat out through the radiator.Since this has seemingly fixed your problem, and you said your others didn't even open (which i'm assuming you checked via the pot of water/thermometer/watch it open as teh temp rises method) then your problem is obvious. Get a proper thermostat in there. As was also said, it's very possible to get a bad thermostat right off the shelf. Had it happen to me. So you replace it, not give up. Beyond that obvious problem, have you checked to make sure your air dam is in place.
As for teh fans not coming on, did it occur to you that perhaps you have a bad relay or connection somewhere?

I'm really sorry for being a *****, but thats why thirdgens end up being looked down on so often. there are way too many people out there butchering these cars cuz they're too lazy to spend an hour solving the problem.

The number one reason you don't want your car to run too cold is this: you will greatly accelerate engine wear. As the engine heats up, the tolerances get tighter. Pistons seal better, and the bearings have less play. Also, if you're running way too cold your engine won't get into closed loop, costing you gas mileage as well as: engine life. Yup, by running in open loop, compounded by the looser tolerances of your cold block, the overrich mixture will bypass the rings and get in your oil, breaking it down causing even more wear. And lastly, with a seriously cold engine, combustion efficiency is greatly reduced, costing you further gas mileage and power.
I can understand rigging a beater to just get by, but you can't expect a performace car to live the way you are treating it.
...ed

btw, electric fans rule. Clucth fans are always a hassle, often not engaging at the right time, causing overheating in summer traffic, etc. Your only consolation here is to replace it and hope the next clucth works a little better. Considering you're too lazy to geta working thermostat i don't think you're up for this, esp. since they cost considerably more than a thermostat. Plus they are noisy, cost power and efficiency. With an electric fan, if you're not happy about the on temperature you can hook up a simple switch to ground on the relay and turn them on manually whenever you want. Takes 5 minutes to connect it. Of course instead of taking this simple route you just hooked them up to run all the time, possibly even bypassing the relays by the way it seems you do your wrench turning.

 

Woah, didn't expect that coming.

Im not much of a gear head. like i said, im a computer geek (profile). The reason i come to this site, is because i do want to learn how to work
on my car, and get everything running. Even when i was a kid, i didn't take apart my toys, i did that once, and couldn't get it back together. i
learned from that one occurrence, and never took apart anything again. Never been good with my hands. Dad also died way too early on in my
life, so i didn't get that "free" car knowledge that im sure the rest of you got.

I have even posted a story joking about my lack of smarts on cars.

Anyway my point was i didn't know much about my car, except it was overheating, i had no money to go to a automotive repair place, and
have them charge me 2,000 for a repair. i just thought, "ok, i can make the fan always run" then when it still didn't help that much, after i
changed to the new thermostat, and it still didn't run right, i took it out. i figured it was the problem.
the car ran much cooler, and didn't overheat at idle. I thought i had solved the problem.

Thanks for the suggestion on the radiator cap, i actually didn't replace it after i went to my all aluminum radiator. i wasn't aware that they could
really cause problems.

I just expected people to be a little forgiving here, not go for the throat. how the ƒuçk was i supposed to know what i did was wrong?

guess im just too lazy to understand what the problem is.

[This message has been edited by Christos (edited January 26, 2001).]

 

Christos, dont let it get you down. We've all had seemingly impossible problems with our cars. Try the suggestions given above, and if they dont help, you can take the car to my dad's shop and have him diagnose it. He wont charge you $2000, but if there's a problem it will cost money to fix it. Good luck.

 

Sorry, i'm just having a bad day. I've got a new guy in my office who's bugging me all the time.
I really didn't mean to come off like a ***** and i apologize. But, you should be able to take something from my scolding, and that is, instead of throwing your hands in the air and looking for a fast solution, look for the right solution. If you can work with computers you can work with cars, they're much simpler. I'd rather have to pull my heads than re-install win95 on my dinosaur Dell P133.
Coming here is a good start, we can help you with identifying possible bad componenets, and as long as it doesn't turn into a book we can guide you through the diagnosis as well.
Once again, i'm sorry. Communicating online is tough cuz it's hard to tell the tone of someone else and it's easy to take the wrong way. I'm a direct sort of person, but in person i at least don't sound quite as much like an a$$hole (sometimes...lol)
...ed

------------------
Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

yes, you did really give me alot of ideas with your post! i did all of this months ago, and just wondered if it was really bad for the car.

wasn't looking for an apology really, just wanted to make sure there wasn't any negative vibes here, heaven forbid, haha this is my home practily. im here all day at work.

thanks for the suggestions, i should really pickup a new fan relay, and 180* thermostat, and see if i can hook everything back up correctily. whoever owned the car before me really screwed with its electrical system before he sold it.

thanks!

 

yah, electrical systems seem to be the first thing people like to screw with before they sell a car, both the Irocs i bought had electrical probs, lucky for me my dad is an EE, helps a little bit...
by the way, my room mate is from near you, laguna niguel I think.
Mo

 

Check out what Stewart has to say about that.

http://www.stewartcomponents.com/techtip3.htm

 

Sorry Brent, I can't believe that. What it says makes no sense. Doesn't he realize that with presure, the boiling point increases?
It's a fact, not theory that when the water stays in the radiator longer it cools more. That said, when the water in the block is "closed loop" (which it is not) that the water will boil away. The boiling point is changed, and the thermostat will be opened way before the water actually boils.

I'm sorry, but anyone can put anything they want onto the net, hell, I've got a 750w, 4 channel amp, that really puts out like 5w.

 

Got a scan tool or access to one? Or you can download a free one if you have access to a laptop. May tell you alot about your problem. You said you were a computer geek, get that computer to work for you to figure out your problem.
Ed pretty much covered it. I had a bad rad cap, never thought about it being the cap since I had never had one go bad, until a friend that knows nothing about cars said his was bad and did the same thing.
Anyway, could be a bad CTS switch in the front of the manifold that commands the relay to turn on the fans.
Running your fans all the time will burn out the motors sooner or later, costing you even more $$$.
Test your thermostats before you put them in, set them in a pot of water on the stove with the stove set low and a $5 temp gauge in the water and watch it to make sure it opens when the water gets to the specified opening temp
*
Running no thermo may cool your motor more if in stop and go traffic all the time, but at higher rpms, the water will be rushed through too fast as said before.

------------------
Rob
High Performance & Party page
Pics of my rides past & present and recent party pics!

89 TTA #426 20th Anniversary turbo 3.8 bone stock
94 Silverado Tuned Port Injected
87 Grand National- lil' ole V6, highly modded
95 Trans Am Conv.- LT1