Pro_built7

iTrader: (9)

hey guys i just took my Z out after al the winter mods (in sig) its untuned, and running it is staying at about 210, (1/2 way on guage) and it will creep as high as 3/4 on the guage (or higher!!) at idlewhich is 235 degrees. why is it running this hot??? the rad is full, theres no air bubbles, but I THINK the fans aren't kicking on??? anyone got any ideas ?

IronOutlaw

iTrader: (4)

fans dont come on until 210 degrees. i had MAJOR problems with my car overheating when i first got it. now it doesnt get over 210 at idle and stays at 180 while moving. 235 is deffinitly too hot.

Now i do know that green antifreeze and the dexcool dont mix. if you mix them they create a gunklike stuff that stops up everything.

also, the fans are supposed to kick on when you run the AC, so you could try that to see if they kick on, but even with no fans running your car shouldnt get over 180 degrees while going 50+ miles per hour.

if your running hot while going down the highway my guess would be a stopped up radiator.

Pro_built7

iTrader: (9)

what happens is it will stay at 210 even while on the highway/normal streets, then at idle it will creep higher which freaks me out. (oh and- factory fans come on at 226) it used to run at 180 (1/4 on guage) before the mods, I thought i completely drained it when i did the cam swap..? i refilled it with green antifreeze, im guessing that the only dexcool left in was probably a little in the block... what do you think? I don't hear my fans coming on tho?

LT1

iTrader: (1)

Engine turns off fan's if you go higher speed than 48mph.

Primary fan turns on at 226 degree's

Secondary fan turns on at 235 degree's

IronOutlaw

iTrader: (4)

thats exaclty what my car did but it would jump from 210 to the red whenever i stopped. your fans may not be coming on, which could be part of the problem. but if any dexcool was left in the engine it may have stopped up the radiator. if i were you i would confirm that the fans are not coming on, if they are then i would get the radiator flushed out or replace it.

my mom had a 1998 minivan that we replaced the water pump on. we just refilled what water and dexcool that came out of it with green antifreeze. then the real problems started. inside the reservoir you could see brown gunk sticking to the inside of it. i dont think it takes much of the dexcool to become a problem when mixed with the green.
not trying to scare you im just talking from personal experiences.

IronOutlaw

iTrader: (4)

i think it must depend on the year model because i know that both of my fans come on at 210 but they are in low speed. mines a 94 obd1 though.

infinitebird

iTrader: (11)

If your fans come on at 210 then you have a tune. stock settings are 226/235.

To the OP, yes 235 at idle is normal if it's hot enough out to need the 2nd fan. Most people don't realize this. If you want it to run cooler get a tune or put in a fan switch.

HoLLo

iTrader: (17)

Check to make sure your air dam is installed below the car. When I bought my car, my LT1 was overheating always 210-235. NEver could figure it out. Bought a $10 air dam off ebay and temps stayed around 190.

halucinator

iTrader: (3)

Air dam is always a good thing to have on these!
TO THE OP: Check your fan Relays, fuses, and also, make sure you plugged the fans back into the wiring harness. Don't forget about the coolant temp sensor also.

HoLLo

iTrader: (17)

Would a bad coolant temp sensor (the one that controls the fans) cause the fans never to come on?

ss.slp.ls1

iTrader: (36)

^^^True.

^^^Yes, the temp sensor on the water pump can cause the fans to not come on. The temp sensor on the head is only for the gauge in the dash.

hi officer

i was having a similar problem where only one fan was running. turned out to be a bad relay

Pro_built7

iTrader: (9)

ya my air dam is on lol,

is this just normal operating temp? I mean, it used to run cooler (1/4 guage) and now it runs 1/2 guage running- near 3/4 at lights.... seems like the cars running fine? do you think im imagining things or is this really to hot?

Pro_built7

iTrader: (9)

Is there any chance it could be the thermostat ?

ss.slp.ls1

iTrader: (36)

Read all of this:
http://shbox.com/1/4th_gen_tech2.html#cooling

caldercay

Look up, from underneath, at the front of the radiator and make sure you dont
have a bag or plastic or whatever stuck in front of the radiator fins. I've had this
happen to me - going down the freeway, I saw a plastic bag fluttering around and
when I "ran over it", I looked in the mirror to see if it came out the back - it didnt.
Within 5 minutes, the temp gauge is creeping upwards - I pulled over, found the
plastic bag and yanked out out from in front of the radiator. All was fine afterwards.

Green3spd

iTrader: (7)

So you installed a cam.... If you leave it to idle will it contiune to climb past red or does it stop about 235F....? I guess I have a tune...lol, my fans come on at 192F... but the car was owned by an older man and I dont see him doing anything like that... DEF check the Relay... VERY SIMPLE CHECK... I also had a 160 Thermo in it...
One test I did on a former car was I took the relay OUT and I "JUMPED IT" with a short 2 inch wire... Fans should kick on and stay on HIGH... Leave them on and go for a drive to see if it overheats....

HoLLo

iTrader: (17)

Next question. would a bad temp sensor cause a fan not to turn on also when you turn the AC on?

Pro_built7

iTrader: (9)

are you saying it running hot could be due to all the new mods and cam with no tune??? it seems to stop at about 3/4 guage.. im assuming thats about 235 but i know the guages are inaccurate. where is the fan relay located?

Green3spd

iTrader: (7)

relay box under hood.... have you let it sit for awhile at 3/4 at idle...? I know its scary but try and see if it rises....