Well, my IROC refuses to run at what I consider are normal temps....on real hot days here it will clock up to 240 and above. The other day, I noticed that the temp would come dramatically down while at stop lights and such, and would increase while driving. Thanks to reading this and another thirdgen (local) website, I began to suspect an air flow problem during periods where the car was moving......when the car was stopped, I could see the temp needle going down. When I got home, with the car still on I checked under the hood and both fans were going, without the AC being on. In another thread in this area, one of the members had posted a picture of an air dam for his trans am....and I realized that my IROC did not have one of those. I looked under the front where the fog llights are, and below the radiator there was no air dam, deflector...whatever you want to call it (Chevy calls it a baffle). I saw the screws where the thing was to be mounted, but no baffle.
Well, I have one on order now....and hopefully this will greatly help my heat problems. The friend I purchased this car from owned it for 7 years, and had it in the shop several times for this problem, but no one realized the air dam was missing. Think that when he had the car painted many years ago, it was removed and never re-installed. Whatever the case, that is the next step in my cooling problem solution (hopefully).
Thanks to this web site and HRTHIRDGEN, as both sites and those of you that posted gave me many clues as to what I should expect, what I shouldn't, and what may be wrong. Will keep posted on what happens when I get the baffle and install it....I can't wait!!

 

thats good news, i hope the air dam is ur problem.. what is the temp it runs at low speeds or idle?

and welcome to thirdgen.org

 

My temp runs down to 220 or below....last nite had the car out for a spin (was pretty cool here) and needle was under 220 unless I was running pretty good....which I tend to do sometimes.. . The fact that the temp comes down pretty conistently when those fans are on tells me that the other parts of my water system are probably doing their job....just need the air dam to cool the radiator while at speed and the fans are off. Having read all the notes in this area, though, I am cautiously optomistic.....

 

ok what exacly is the air dam on these cars ?? is is the black pastic filler shelf thingy running from the backside of the nose assmebly back to the radiator support underside ?? i suppose all models 82-92 got one or ? would an 84 Z28 with gfx and everything have this dam or something better,
or this dam plus soemthing else,
or ?

thanks

 

In my experience on a truck with the air dam, the cooling difference was minimal. Not that your car is a truck of course, (have a feeling air dam on trucks was more for "smoothing" air going under the vehicle because of the 4wd stuff instead of cooling) I'm just not sure HOW effective the air dam is in your case.

Obviously GM would not have installed it had they figured out it did nothing, so I'd suspect it will help, but I'm not sure I'd expect your problem to be 100% solved. Removal of the air dam causing that much of a problem would *really* indicate that GM had those cars right on the ragged edge of acceptable cooling, and GM doesn't typically like to run anything right on the edge.

One thing I did notice though, was that you mentioned your fans are on. IIRC in most cases, the fans will come on whenever they need to, but at cruise, fans *typically* don't help. I know the electrics draw a lot of air, but at 60MPH, I'd imagine airflow is faster than the fans can pull air, and they are doing nothing at that point but restricting airflow.

Perhaps it is in conjunction though...the fans are on because the vehicle is hot (I'm *assuming* they aren't on all the time the vehicle runs, because I know thats not right) and the vehicle "needs" the fans because the airflow through the radiator is insufficient.

I am curious to see how the air dam works for you! You've already ordered it, so its not like doubting its effectiveness now helps anything : ) Its not like there is much else that can be the problem, radiator, pump, thermostat, and block condition are really the only factors left in the cooling equation, and none of those should be causing the problem you describe. One thing I just thought of though, make sure the radiator fins are not full of bugs and junk, and if you have AC, make sure both it AND the radiator don't have the fins full of junk.

I guess I'll have to keep an eye on this post now

 

 

Well....the air dam makes a HUGE difference....at least with my IROC at this time. I installed it this afternoon, and anxiously took my Z-car out in 100 degree (with the heat index....it was pretty HOT).....As I drove, I waited and waited for the temp to climb....but it never got above approx 180.....and it only got to that temp while sitting at stoplights, as soon as I started to move at speed, the temp gage would drop down again to about 160....FANTASTIC!!! :lala: I had the car out for about 45 minutes......in screaming hot temp.....where previously I would have clocked in at above 220......now my car is running at temps that are what I consider to be normal, never close to 220 mark. Next will be the extended drive during a hot day....but I am here to tell you that if you don't have an air dam and are experiencing high temps.....then, get the air dam, you will be amazed at the result......

 

Haha! Glad to hear it makes such a difference! So you've basically duplicated or exceeded the conditions that before overheated your car, and now no problems? That is amzing, I agree. But glad to hear it worked! Pretty simple fix!

Dorian

 

that is very interesting indeeed..... hmmm
where in relation to radiator mounting point exaclty do our dams mount at under there ? and while im asking whats the point of the plastic flap cover deals mounted to undrside of nose oly on the two ends of the nose at very frot under there ? held on with little screws)
my pass side one on my Z28 is hanging off for soem reason, halfway off,

good luck

 

Fast68

My air dam is right below the radiator, just in front. The bolts were already there....6 of them. From Chevy, the air dam cost about $33 bucks....think that it was a little cheaper on the web, but with shipping cost and the fact that the dealer had it onhand, I went ahead and got it locally. And, I still have not come near 220 yet even on scorching days here.....as a matter of fact, on the cooler days in summer, I am now running below 160 consistently....so I am going to have to get a 180 degree t-stat or a 195 one, and replace the 160 currently in the car. ***, I love running cool!!!