s25hanh

iTrader: (8)

Hi guys, I have a 99 camaro z28 with 5.3 TT front mounted. I cannot figure out why its overheating, I usually never post on here until its the last draw. And its the last draw. 160* t-stat, fans come on at 176* (two 10in ebay fans, 850cfm each). Bleed the system multiple times.

Cold start it will idle and get to about 190* and never go over.... Until I start driving, then the temps will rise to about 210*. Sitting in traffic is the worst. It will rise to 220-225* and then SLOWLY go down to about to 215* driving but thats about it.

I still have the factory air dam on and turbo blankets. The only thing I can come up with is the lower rad hose is RIGHT above the passenger turbo. Please help, this issue has stopped me from driving it for about a month now.

asubennett

iTrader: (6)

What are you using for coolant crossover on the motor? If using a kit and the highest port of that kit is higher than your radiator cap you will have a hell of a time bleeding the car no matter how many times you have tried.

s25hanh

iTrader: (8)

stock ls coolant crossover

willizm

iTrader: (10)

Did you burp all the air pockets out? Was it a fresh built motor?

s25hanh

iTrader: (8)

Yes its a fresh build and I bleed it with the rad cap off, cold start, and let it cycle through with the heater on full blast.

forcd ind

iTrader: (7)

i always fill the block from the top hose, lets water get behind the thermostat
I gotta ask, are the fans wired correct, blowing inward-I have seen several times wired wrong
also do you have an A/A IC'er, blocking the radiator
the fans may just not be moving enough air

LS6427

iTrader: (2)

Did you remove the factory shroud....? is it still sealed to the front of the condensor just like it was from the factory...?

Also, believe it or not....a 180 tstat will help more than a 160. More time for the coolant to cool off sitting in the radiator before it goes back into the engine/heads. Once those 160 tstats open and its above 190-200 that tstat will never fully close and the hot coolant just keeps moving and getting hotter and hotter........then its all over......
The tstat must be allowed to close......

But without the shroud in place like it was from the factory....you will never run proper temps.

Also.....aren't the factory fans 1,200 cfm each.....? Not sure but I thought so.....

......also....make sure BOTH fans are coming on together.......in both low and high settings. They always run together.....

.

s25hanh

iTrader: (8)

Yes they are wired correctly because I tried switching the wires to making the fans pushers and made the problem worse. I do have an a/a IC basically blocking the rad. I don't know what fans I could go with though

No AC so I don't have the condenser. I can't fit the factory fans with the turbos being right behind the rad. Hmmm I might try going to a 180* t stat then. And both fans come on and they are at the high setting all the time past 176*

ablakez28

iTrader: (9)

Do you have a picture of the fans and the shroud? I battled cooling on my old RX7. Best I ever got was a 200-205 in traffic temp.

Also sorry if i missed it but what rad? Stock?

Chris@CBR

Can you post a pic of your setup? Have you done the LT1 rad upgrade?

tonypaul

iTrader: (2)

Do you have the fans as pullers or pushers? I bet those fans are not strong enough...

Cam72aro

iTrader: (28)

You need a lot more fan to start with.

fire67bird

Check your timing and AFR. The link below is for carb. engine but the principles are the same:

http://www.hotrodders.com/forum/timi...ng-160577.html

oscs

iTrader: (19)

Letting your coolant "sit" in your radiator to have more time to cool is a myth And has been proven many times. Do some more reading.

OP your 160 thermostat is fine

oscs

iTrader: (19)

I'm a bit confused. You say @ cold start it will idle @190 with no issues? But when you start driving it over heats?

turboventura

If you are running an automatic trans keep your trans cooler off the rad, my car never got hot but when I put a large plate style trans cooler in front of the radiator (touching it with those plastic things that connect through the rad) I started getting hot while driving. Relocated to somewhere else on the core support and its staying cool now. It's also an unlocked th400 with 3500 stall and 3.23 gear so it makes some heat.

lysergic

almost guarantee its your fans. they are not up to the task.

lysergic

dont bother chasing anything else until you put some big powerful fans on there. i have been through this. use two of these:

http://www.summitracing.com/parts/der-16925

MAKE them fit

Cam72aro

iTrader: (28)

X2. Those eBay fans are junk. Get these fans to start with then go from there.

oscs

iTrader: (19)

His car idles @190 with no issues.. but over heats when he starts driving. The fans are NOT where I would start looking.