GT4 Hood Vents. Options

[njccmd2002]

I know some of you prefer to keep the main vent uncovered and had it for many years, and not a problem with it. Fine. keep it like that.


Unfortunately I had done that, and in couple of months, it did not do me any good. My engine got weathered, and exhaust manifold rusted.

That center plastic drain, can the water spout be rerouted, I have heard the position that the water hits the radiator and its hot, and it cracks, but i would think toyota would not have done it otherwise.

any ideas, i want to go back to the GT4 hood once i fix it, but wont like to deal with that mess.

your comments are appreciated.

[richee3]

I found the post that tells about the radiator cracking. It was in the GT-Four Front End Conversion sticky.

7. Will it be bad if snow or rain fall in through the center hood grill?

All GT-Fours came with a plastic cover mounted between the hood grill and the hood insulation. It catches rain water and directs it to the front where it falls on the radiator improving cooling. However, this weakens the end tank of an oem radiator due to the changes in temperature (expansion and compression particularly in cold weather climate) on the composite material. After 2 years my oem rad developed a crack causing the engine to spew out coolant when it was about -40 degrees. so I purchased a metal radiator (from performanceradiator.com aka USA Radiator). Most people remove this plastic cover as it improves cooling by releasing the hot air trapped in the engine bay. There is no real potential hazard with rain or snow falling through since rain drops and snow flakes will quickly evaporate as it reaches or comes in contact with the header or heat shield. If your car can withstand an engine bay wash, then it should withstand small rain drops or snow falling through.

So it seems an aftermarket aluminum radiator should be good.

[njccmd2002]

yes i read his situation, but my car withdstands rain outside while not running, hence the engine not being hot... its a catch 22 then.

[BonzaiCelica]

i cant find that thread that azain advanced posted.

my guess would be to cut the original oem plastic molding so that it drops off right in behind of the radiator fans and in front of the header....

it take a few try's. but slowly start cutting at the plastic till it drop directly in that place. do you understand me?

ahh wait that piece wont stay on there unless you have tape or the inside gt4 insulation





This post has been edited by BonzaiCelica: Feb 21, 2013 - 2:32 AM

[njccmd2002]

it does stay in there with clips, does not need the insulator. but thats a good idea.

[presure2]

i doubt VERY highly that drips of water are what caused the radiator to crack.
its very much more likely to have cracked from the natural cracking that occurs over time in the top end tank in all stock celica radiators, that is exasperated by the heat created by the turbo and manifold.
all plastic end tank celica radiators degrade and crack that top end tank over time, and in turbo swaps and 4's it happens more often because of the turbo heat
had it happen to jenn in her car while going down the highway. because of the vent in the '4 hood, it sprayed coolant all over the windshield, totally blinding her. luckily for us, she didnt panic, and just slowed down and used the little visability she had to get off the road (wipers just smear the coolant around the windshield, making it worse)

[njccmd2002]

^^ thats what i think too, i dont think toyota would have overlooked that

[presure2]

^^ thats what i think too, i dont think toyota would have overlooked that

yea,..i mean, if i haddnt seen the cracking that always happens, on every stock celica radiator i've ever seen thats over a few years old, i might think otherwise, but, its just a natural thing that happens over time with the plastic end caps.

one thing i will add, is that i do believe that the turbo setup accelerates the process, because of the added heat of the turbo that much closer to the end tank.

[njccmd2002]

now that i think about it, i threw away the insulation, and that plastic above the heatshield might melt... sucks....

[lagos]

Rain water hitting your radiator will not do any harm. Your radiator already has water (and coolant) inside of it on a daily basis. What makes them crack is the fact that the plastic becomes hard and brittle with age. Hence why you should inspect your radiator and replace it if its starting to look bad.

As for keeping the vent open its totally fine, but remember that the GT4 has a heat shield covering the exhaust manifold and downpipe. If you are running an NA motor with a header, then it would be a good idea to fabricate a heat shield to protect the header from water exposure.

This post has been edited by lagos: Feb 24, 2013 - 12:34 AM

[richee3]

I have the heat shield over my header and it's starting to rust. I definitely need to get the main vent covered. I'll probably have to fabricate something and it won't be pretty but it'll work.

[njccmd2002]

thats when i tought about fiberglass, but if it gets too hot, may not work

cuz it will definetely melt the plastic

[delusionz]

you guys dont remember my alloy shield? ive considered redesigning mine as it traps alot of heat in -- work fine for you NA guys though, just the GT4 makes alot of heat not just from the turbo but the extra stress from 4wd/weight.

keeping the water off my manifold is the main thing though, and it drains right at the radiator (more like ontop of the fans)... but this isnt where the hot air is, well it is, but the turbo & manifold are hotter

[richee3]

I picked up a piece of sheet metal yesterday to fabricate something similar to that. Mine definitely won't look that good though.