z28pat

iTrader: (10)

this was strange,
I was driving to work and stoped by the bank, while waiting in line the car started heating up, to just below the red line. so I rushed to work to park the car and as I was driving the temperature started to go back down to the middle (210),

well after I shut the car off and was walking away, I heard that the fans were still on, so I popped the hood and they were on!!,

I turned the car on and off again and the fans finally stopped.

why would it do that?

pat

9000th01ss

iTrader: (10)

Have the fan on/off temps been changed in the tune?
Stock tune has the fan stay on for x amount of time after shut down if the temp is 234? or above.
Stock gauges don't always read accurate either.

z28pat

iTrader: (10)

didn't think about that,
the car does have a 160 thermostat now and it was tuned so I believe the tune was changed to account for this, so could this mean that it's overheating? it's full of coolant

pat

9000th01ss

iTrader: (10)

It really depends on the tune, usually people don't mess with the settings that make the fans run with the key off.

I know for a fact on my 2002 I had HPTuners connected and manually shut the fans off and seen the temps go up to 225* with the gauge showing 210*

It could be your fan relays sticking. I'd just pay attention and see if it does it again, if it does try to find out when they are tuned to turn on and off.
Where does the needle usually stay when it's running right?

2001NBMZ28

My helms says fans on after key off for a couple minutes is triggered at 284* so they're staying on because of the overheat condition w/stock tune.

shoemike

iTrader: (25)

{G0909} fan #1 run-on temp is set at 235*F on a stock 02 Z28.

z28pat

iTrader: (10)

So how do I check if it's actually overheating since the gauge is really a dummy?
it usually shows 210 when driving normally, but this is the 2nd time the gauge has gone up close to the red?
there are no visible coolant leaks,
so waterpump?

pat

shoemike

iTrader: (25)

your t-sat might be a problem, but like i said if your tune is stock
the value of the table that controls your fan is set to 235*F
which is not high if your other fan temp table and t-stat are also stock.
{BG0901} fan #1 on temp is 226*F and
{BG0913} fan #2 on temp is 234*F in a stock tune
together with a hot day you will end up with
the fan staying on after the car is off.
as far as getting accurate readings for all the sensors of the car
you will need some kind of tuning suite/device to log data from the ECU.
what is the high temperature in you town?

9000th01ss

iTrader: (10)

This is a little different than what I first read.
If you have a 160* thermostat and it usually runs at 210* then you need to get your fans to come on sooner. That 160*t stat was a waste of money with a stock tune.

Is it full of coolant and hasn't been messed with lately?

The only time my gauge ever got into the red was after changing the t stat, I guess there was air behind it because it hasn't done it since.

I would guess a bad t stat is the problem, from my experience water pumps never stop pumping they usually start leaking. Or it's low on coolant.

z28pat

iTrader: (10)

thanks for your help,
I'm gonna get a new Tstat and replace it hopefully in the next 2 days
and post an update,
by the way it's been extremely hot the last 2 weeks here,
easily over 90F we've set a couple of records,


thanks again

pat

needadvice

don't know why fans would ever run after an engine is shut down, its not doing anything to cool the hot coolant in the engine and heads. Who cares about cooling the coolant thats just sitting in the radiator.

9000th01ss

iTrader: (10)

Stock fan settings FWIW.