ZZ3Astro

This is really aggravating me to no end! A little history:

Stock (fairly worn 148k mile) tpi 5.7 with single turbo. Factory aluminum 'wide single core' radiator.

This car has always felt marginal on cooling. Since putting the turbo on, if I ran the AC the coolant temp would slowly climb to 220ish and stay there. Once I put the intercooler on and restricted the air flow, I immediately found out the fog lights and trim panel/tag bracket would not work (even with the AC off). I cut out a hole in the center of the crash bar and left everything out up front and it works fine. However the AC could only be used if you could stay moving and it wasn't 98 degrees outside.

Fast forward to this summer.. it's HOT out and I refuse to drive around without AC. Reading various threads here it seemed like LS1 fans were the ticket. I ordered a fan assembly and promptly installed it. Well it allowed me to drive around a lot longer with the AC on in hot weather, but still creeps up on temp into the 208+ range. Once it gets beyond 200 it goes into a 'meltdown' mode where it just seems to feed itself.

Ok, so forget AC for the moment. Let's put the fog lights back in along with the trim panel. Now the car looks like an Iroc again. Nice cooler night air around 82 (florida cool!). I take it out for a no boost drive to the store. It slowly came up to the thermostat temp (185) and stayed there. Nice, foglights might finally be able to stay sans AC. I shut it off and go into the store for 10 mins and come back out to a heatsoaked engine. Coolant is about 205. I drove very easily 5 miles, even locking the converter and it never got lower than 202. I made a little boost on the final stretch and parked in my driveway at 212 degrees.

As a final test I sprayed the water hose on the radiator core and the coolant temp immediately dropped to the 180's, so obviously the thermostat is working fine. Had I just shut it off, it would have dumped half the radiator out through the overflow jug. Mind you the overflow is smaller than the original but it still shouldn't be dumping out that much coolant.

So my question is to those of you that have installed a FMIC in front of the radiator and what kind of results you had with a stock cooling system. I know my engine is acting thirsty lately and isn't in the best of shape, but the issue for me is that using the AC or installing the fog lights makes the car undriveable. If I leave those off it's fine. Would it be worth buying one of the 3 core replacement ones from O'rielly? I'd prefer to stick with the lighter factory one if possible.

ZZ3Astro

I know these questions will come up:

1> Is the air dam in place and undamaged?

Yes!

2> What are your fan settings?

Fan #1 on at 100 degrees

Fan #2 on at 195 degrees, off at 185


Oh and to clarify, even with the two stock fans it was fine without the AC on and with the fog light stuff out of the way. The exception to this was multiple hot-laps at the drag strip - same thing once it exceeds 200 it's over.

Thanks!

evilemokid94

iTrader: (6)

these cars run 220 normal.....

TTOP350

iTrader: (8)

I would run a 160 T-stat and this 2nd fan switch.

http://www.summitracing.com/parts/HY...Make%7cPONTIAC

ZZ3Astro

I put a 160 in it tonight and reset the fans to:

1> on at 100
2> on at 170

With the fog lights and trim panel in, AC off it very slowly warmed up. Once it got to 160 it kept going to 175. It was still climbing but too slowly (4 miles of city driving) so I threw on the AC. It very quickly went to 197 and I turned off the AC. It continued to climb to 203. I pulled over and removed the trim panel/tag bracket to expose the center opening I cut in the crash bar. This stopped the temperature increase but it never went below 200.

Obviously either something has changed with the engine or the LS1 fans aren't working as good as the stock dual fans were. I guess my next move is to put the stockers back in and see if the car still runs warmer than it did before I put the LS1 fans on. Weird.

86Z

iTrader: (4)

i dont have a fmic, i have the undermount 3 core, and my car gets hot with the a/c on, it seems to happen mostly while high speed highway cruising, i have the stock dual fan setup with both fans running all the time, 160 degree thermo, stock replacement radiator, granted i dont overflow like you stated, but my next step is an autometere coolant temp gauge, cause the factory one is just plain inaccurate.

ZZ3Astro

It looks like I'm dealing with two issues here then. It's obvious the stock cooling system on these cars works at about 95% of its maximum capacity. Anything placed in front of it that reduces airflow at all or increases the temperature of incoming air in the slightest is enough to start the under-cooling process.

Secondly, something is obviously going on with my engine. I forgot to mention last night it was stumbling at full boost. Almost feels like when you don't have an MSD box and you put more boost in than the stock ignition system can handle. Bad timing on this problem, I have two events I wanted to go to before I do my engine build. Oh well.

Guest

turn the a/c off take the fog lights out and tough it out....

86Z

iTrader: (4)

nice problem solving there...

ikeepitreelz

I think your air damn is either missing or just bent back too much to provide enough cooling.

ikeepitreelz

I agree..hence thats why we are posting here

TTOP350

iTrader: (8)

Im kinda wondering if you have popped a headgasket...

ikeepitreelz

I dont have the tell tale signs of a bad headgasket, anti freeze is clean , no white smoke, no bubbles in rad. Oil doesnt look like vanilla fudge. My next solution is to sell it and get an import.

ikeepitreelz

The last sentence if course is not true death over imports lol

TTOP350

iTrader: (8)

Not all head gaskets failures do those things.. goofy I know but it can happen.

Friends dont let friends drive imports!

camaronewbie

As mentioned - these cars run hot. And, 200 (even 210, 220, 230) is NOT too hot! A stock dual fan TPI car's secondary fan doesn't even come mon until 238F.

So - why is everyone's panties in a wad over 200F?

Radiator does NOT get any airflow through the foglight holes (on a stock car) - it all gets sucked up from below, just in front of the radiator - that is the purpose of the air dam, to create a vacuum behind the radiator and thus suck air through from the front side ... so foglights are not an issue. This design is the same as a 'Vette - there is no direct airflow through the front of a 'Vette either.

Now - the intercooler might be an issue ... it might be getting hot (since it's not getting any airflow from the the fog light holes), and thus increasing the temps of the entire system (creating much warmer air in front of the radiator that the air dam is sucking in through the radiator). But I'm no intercooler expert either - this is simple brainstorming.

Might try a new temp sender, or an aftermarket guage - maybe it's not as warm as you think. These guages are at best just little "look pretties" intended to sell cars.

But in the end, 200, 210, 220, even 230 is nothing to get in an uproar over. No matter what ... overheating will occur when things get too hot - and you'll know because steam will be rolling out from under the hood. Until you get boiling over into the overflow tank, or worse, you are NOT too hot.

RyanEricW

Funny that you say that. The one in my car, and my other camaro before that was perfect. Better money spent getting a laser temperature reader and checking the temp of the outgoing coolant to make sure it's accurate. The coolant in the jackets will obviously be a tad more hotter, but that should be taken into account.

ZZ3Astro

Well on my car it is a big issue. I have a 180 thermostat and I have my fans programmed to come on much sooner than stock. I don't want my car to run above 185 and the only time it has since I installed my megasquirt and turbo system is when I have done back to hot passes or ran my AC on very hot days in traffic. More recently after putting the intercooler in place I noticed reduced cooling capacity and less tolerance to AC use. Every time in the past when it has risen above my 185 threshhold, I immediately changed what I was doing (turn off AC or stop hot lapping at the track) in which case it immediately began to cool down.

I am awareof the stock 195 thermostat and the secondary fan switch being set at 238. That high of a temp does not work out well with my turbo setup as there is already extra heat under the hood. I want to keep my runners and intake track cooler. And the most important factor is that I have a 2800 stall and I want to keep my transmission temp cooler than stock. Any excess heat in the transmission fluid just increases the amount of heat generated from converter slip.

Anyway I've pretty much confirmed I have a head gasket problem. As long as I stay out of boost I can drive it a pretty good distance. Once I get into boost a few times it is very quickly over 200.

RyanEricW

How did you confirm the head gasket issue? CLT?

ZZ3Astro

Mostly a combination of all of the symptoms I've been having, combined with finding out it is now getting hot even with the configuration back to AC off and the fog light trim removed. The symptoms are/have been coolant deposits on several spark plugs, burping of radiator during starting combined with a hydro-lock type issue during starting and bubbles in radiator when I rev into boost with the cap off.

That said, I drove it last night to a cruise in about 5 miles away and it stayed at 165-170, even with the fog light trim back in. I didn't run the AC and I didn't turn over 3000 rpm. On the way home I boosted twice and it ended up about 195 when I got home.

Sure looks better with the fog lights in!

86Z

iTrader: (4)

nice looking car...

YenkoZ28

I had a similar experience as you, but with an ATI procharger and intercooler setup. The fog light delete didn't fix it and neither did the twin high flow intercooler. They way I fixed it was to throw an edelbrock high flow aluminum pump on it with flex a lite twin low profile fans and this radiator https://secure.wf-api.com/www.chevel...ng.com/46.html it's the third gen radiator at the bottom of the page.

I'm not sure which one fixed it, but now I'm running 180 with the A/C maxed in stop and go traffic. Hope this helps you out.

ZZ3Astro

**Update**

I replaced the engine (I was building a forged bottom end anyway) and the cooling issues remain! I next replaced the radiator with a new one. This did help, but did not resolve the problem. Finally, out of other ideas, I put the stock fans back on. This resulted in a night and day difference. I can now drive the car for a very long time and the temps stay under 200 (although over the 160 of the current thermostat).

So basically my attempts to fix the intial overheating problems (head gasket related) created a new one (POS aftermarket LS1 fans that suck worse than stock third gen fans). When I put the sealant in the old engine, it did stop drinking water and probably resolved the head gasket related overheating) but because I'd switched to inferior fans, it appeared to have no effect on the original problems. Once the new engine was in place, it became obvious something else was wrong. Now that I'm back to the original cooling system, it's behaving like it did before all of this started.

Yenko, I sure hope I can avoid dropping $600 on a radiator. Ouch. But thanks for the info, glad to know there is a definite solution out there. I might put a for sale sign on this thing before I'm going to drop another $1k into cooling though! LOL

ZZ3Astro

I think I just figured out the straw that broke the cooling camel's back.. I didn't build my new transmission until the cooler weather arrived last winter. I went from a stock converter to a 9.5" 2800 stall. This added heat explains the issues I had at the drag strip early this year. The car would heat up and wouldn't cool back down while running until I got on the highway and locked up the converter. Then once the summer weather arrived, it couldn't run cool enough like it did in the winter. I believe this extra heat going into the trans cooler in the radiator is just getting put into the coolant. I am adding a third fan tonight and will go for a large external trans cooler next.

FSTFBDY

iTrader: (33)

BINGO. that 9.5" converter make alot of heat. You deff. need a large external. a good fan mod is the Ford taurus fans. If I recall right they are a 3speed fan.

You don't need to spend $600 on a radiator. If I recall a few people on here are running these http://cgi.ebay.com/ebaymotors/1982-...ht_7235wt_1165

with good result. I have a buddy back in ohio who ownes a fab shop who makes custom 3core triple pass radiators. around the $350 mark. Id deff. look into a few upgrades in the cooling system. Hi flow water pump , rad. royal purples additive works good also

ZZ3Astro

Nice! That's what I should have gotten instead of this stocker. Price I pay for trying to get it going in time for this cruise-in that I ultimately missed. I'll be ordering one of those for sure. Thanks for the link

FSTFBDY

iTrader: (33)

no problem. I think Justin89Formy was one of the 1st to get and review it on the board here.

https://www.thirdgen.org/forums/cool...guys-want.html

DBLTKE

iTrader: (1)

Why do you want your car to run so cool? There's absolutely nothing wrong with running 200-220*. And why are you having your number 1 fan turn on so early at 100*? You do realize that your car doesn't go completely into closed loop until 176*. If you're worried about underhood temps, then you need to look into ceramic coating the exhaust/turbo, header wrap, and staying away from chrome parts. Have you though about making your hood louvers functional?

vette9190

iTrader: (2)

ZZ3ASTRO

I have been following your turbo build for a while now and I agree. Maybe you need to work on venting under hood heat with louvers or and open cowl hood or even one of those custom heat extractor hoods I've seen built on here. I think that would help alot that turbo has to be creating alot of heat that our cars were just not designed for.

ZZ3Astro

Thanks guys..

I'm running a Megasquirt so I have some variations from those stock numbers on closed loop .. that said, I want my car to run around 180-190. Since I'm running a 9.5" converter, any extra heat just gets multiplied by the slip. My wife complains about hot floorboards and since she runs the laptop during tuning sessions, I gotta keep her around. And I'll have to agree, the car is nothing short of uncomfortable when it's running 215 degrees. Yep I have considered doing something with the louvers as well. I go back and forth between running the rear hood seal and not. To be honest, the only difference I've found with that is smelling the engine through the vents as the cabin air intake is right there. Can't run a different hood, not an option to change anything on exterior appearance for this car.

If I were going to try making the louvers functional, I'll have to start with a junk hood I can cut vents into first. That way I could make sure it is going to help. I just don't want to make the car where I have to worry about rain, especially now with the polished tpi intake on it.

vette9190

iTrader: (2)

No exterior mods what so ever?? Not even fender vents?

Do you have an oil cooler and a trans cooler? Im thinkin' you could get the ones with fans and mount them in the front area of the fenders behind the parking lights almost flat with a slight forward angle. with the fans on there you wouldn't have to worry so much about them getting clean air all the time.
I hope you get this figured out i love your build and am highly considering a turbo build myself.

One more thought have you tried a higher pressure rad cap??

ZZ3Astro

Actually my radiator cap is on the list to be replaced. The rubber is looking dried out. I was under the impression that the pressure in the radiator system is to increase the temperature tolerance before boiling though, not so much for improving cooling.

I do have a factory oil cooler (which is probably just adding to the cooling issues with the radiator) and I recently added a relatively large external transmission cooler, which is in-line in before the radiator cooler to reduce the heat load going into the coolant. So the plan was at least.

I don't want to do any exterior mods to the car. It is very important that is looks 100% factory (no tint either lol). My reasoning is half for car show appeal and half to support the sleeper status. I don't want myself or anyone else to know there is a turbo until I get into the gas pedal a bit.

vette9190

iTrader: (2)

Have you thought about not running the trans through the radiator? I think if you added a fan on the trans cooler and it was big enough it would cool the trans without the need to run it through the radiator too. I'm not a fan of the factory oil cooler, I think its to small to really do anything on a built engine especially with the added heat of a turbo.
I can understand wanting the sleeper appearance. I love torching unsuspecting dopes When they see it says RS on the side and figure its just a V6.
Do you run any additives in the radiator like that be cool or engine ice that are supposed to have better thermal cooling properties compared to regular antifreeze.

cypris09

iTrader: (1)

As someone above said, those champion radiators are extremely nice. Though I just broke in my motor (also still had some decent air pockets in the coolant) the car held at 160 to 170 with both fans running. (Fans came with the radiator). I have followed this for a while hoping I Sony have the same problem. I do plan on "opening up" the front end a bit and making a grill since I do have a fmic hope that'll help with the cooling. I understand you want the stock look but sometimes you gotta give in a slight bit

ZZ3Astro

I have ran air-cooled only before but I have never felt it was as efficient at getting the heat out of the transmission fluid as the water cooler. Not that I want my engine to run warmer, but I'd rather see the coolant temp gauge go up than to end up with a heat damaged transmission.

Haven't tried any additives. I think it's just got too far to go for additives to make the difference. Definitely looking into my radiator and fan upgrade options next.

After I get a better rad & fan setup, if it still runs warmer than I like, I will modify the fog light trim/front tag mount to allow more air in. I've already cut out the center part of the crash bar directly behind the tag mount. Right now I have that trim panel off to let more air in from the front, but I hate the way it looks with it out.

cypris09

iTrader: (1)

I'm not a big fan of air cooled for the trans either. You can get creative with the front to make it look right. Thats what I'm doing. The P.O on my Gta rigged up my air dam and when i took it off it fell into peices. So I hope opening the front will help but I'm sure I'm gona have to fix mine.

ZZ3Astro

Per the suggestion a youtube subscriber, I did some research on Dodge Intrepid fans for my Iroc. Found a set for $50 at the local pick & pull. Luckily someone had pulled the radiator so it was as simple as unplugging the harness.

I installed it tonight with a good bit of trimming on the assembly. I was able to retain my stock plastic radiator support (it sits slightly higher on the back part) so everything looks stock. These are two speed fans and both fans run at the same time either in low speed or high. Just with low speed mode, the car stayed much cooler while driving around. It did eventually reach about 180-185. The second fan pulled it down to 177 reasonably quick but is unable to get much below that, and it isn't exactly a hot night. That is sitting still, but once moving it will cool further. Sure beats 210+

So my point is, there is a good improvement that should get me through the fall and winter. Once the warmer weather comes, I'll need to upgrade to a three core radiator. In the meantime I'll be keeping a lookout for a good deal on them!

cypris09

iTrader: (1)

I also remember someone made a bigger "flap" on the bottomed of the car to help direct more air up into the radiator. If I recall it was only a few inches more and it helped a nice amount.

ZZ3Astro

Nice hot day here in Florida. I was able to run my AC for the last 10 mins of driving, after a hot start and it stayed nice and cool! Won't say it's gonna be good enough for 100 degree summer weather, but other than that it seems quite happy with these new fans.

midias

Have you considered a 3 core radiator?

Also you are auto does your radiator cool your trans at all? Separate the two coolers?