Temp gauge pointing 9:15
 

So is it overheated???
See the attach pic.
thx


Here is the incident...
I was driving to a gas station to pump my tires. I arrived and parked the car beside the pump, which left the engine running (idle). At the time I left my car, the gauge was pointing @ 9. After finish pumping tires (1 min), I found out that the temp gauge was pointing 9:15. I was so scared that I turn car off my car immediately. After waited for 5~8 mins, I turn the key to "ON" (didn't start the engine), the gauge pointed 8:30. After few short "beep"s, there was a long "beep" sound and the water temp gauge light was on (pointing 8:30). I was scared again, so I turned off the car. Then I start the engine, the light went off and gauge pointing 8:30. As I saw the temp was normal, I drove back home. On the way home, when I was waiting stoplight, the gauge was trying to go up above 9:00. However, when the car start moving, the gauge move back to normal 9:00~9:05.

So, iiiiis mmmmmmy ccccar Ok??

PS. here's my condition....
Outside temp 0C,
coolant at AST is boiling when car shut off,
coolant in overflow tank 4 marks higher than "full" when car just warm up, it;s real full (far higher than "full") after driving,
has low idle (500 rpm) problem, sometimes shut down,
normal idle @ 800~1000 rpm,
hear "shuuu" sound when turbos kick in.

OK, looking at the following page,

http://www.geocities.com/MotorCity/G...tempgauge.html

I think 9:15 is about 23 Ohms resistance on the sender, which could be.. well... I HAVE NO IDEA!!!

What I mean is the stock temp gauge is useless at telling you the temp of the motor (you knew that, right?) unless you linearize it. A better question is did the fans come on? IF your parking lights were off while it sat ideling, then the fans are supposed to come on at 221 F. IF your lights are on, parking or full headlights, the fans are to come on at 210F. If the fans never came on, you probably didn't boil the engine. The old threads I've seen about wasted engines as per the stock gauge have the gauge at 10:00 and moving fast when failure was imminent. You are most likely ok, though you need to check your coolant levels at both the filler neck and AST when the system has cooled down to make sure you don't have air in the system (and thus the coolant light).

Do a fan mod, then you can sit and idle forEVER!!!

edit: no pic, and I can't be sure, but for some reason I feel like shutting off the car when that hot is a bad idea, because heat soak will only make the temp go higher. If it gets that high, I would (and DID, before the fan mod) wait until the fans had come on (again, I always run with the running lights on), wait till they go off again (at 195 F), and THEN turn it off. Unless they don't come on at all, then you're screwed. Honestly, testing the temp at which the fans come on with a non-linearized gauge is a practice in puckering the orafice, ya know?

o
sorry..
forget the attached~

here u go!

By the way, how do I release the trapped air in AST?
I have try to remove the caps of the AST and filler, but I cannot do so. It seems that the caps are stuck somehow. No matter which way I turn, they seem don't wanna come out.
Also, how to engage the fans @ lower tempature???

You have to push down the cap on the AST and twist to get it off.
Take that cap and the filler neck cap off. Then take off the coolant hose on the throttle body.

if i pull off the coolant hose on the throttle body, will the coolant spill off???

stupid question~
where is the coolant hose on the throttle body?

thx

Standing by the driver side fender looking at the TB upper right hand corner (that's where you'll find the coolant hose). But honestly, take the car to a good mechanic and have them check for traces of exhaust in your coolant.
Also look for small air bubbles (at the filler neck with the cap off)when the car is warmed up and idling. If it is there, you have a coolant seal leak.

get ur coolant system pressure tested. I had these symptoms as well, coolant light at ACC, but while driving the temp gauge seemed fine. That temp gauge is worthless. I had no idea what temps I was running at, neither did I know what kind of boost I had, since I had no gauges other than the crap stock ones. Anyhow, I could audibly hear coolant rushing through my heater core when I would gas it, from inside the car. My system pressure tested fine up to 20 psi, but I don't know how long it would hold that, because I didn't ask my mech. Anyhow, I blew my motor a week ago, and am in the process of figuring out what IM gonna do for a rebuild. Not to scare u in anyway, because from what it sounds like, u have air in the system, and should be okay once u find the leak. It may be the overflow to AST line, because I fixed part of my coolant problem by replacing the line, and the AST. Hopefully it isnt a coolant seal. Do u get smoke at startup? Heavy sweet smelling white smoke?

Ur idle may need to adjust the dashpot for the idle problem. I too had this, but I think it was because my compression was a tad lower than it should have been, although equal in each housing.

Good luck.

For the coolant problem~
i don;t have any external leak at all
I do have smoke at start up~
but it's so thin and smell like gasoline, not sweet at all
however the smoke is thicker when outside temperature is lower

this is the first time i got the coolant light on~
but isn't the coolant and pressure light on when it's on ACC????

Ok
I just open the filler cap and AST cap. Initially the coolant is full when I open the filler cap. After open the AST cap, the coolant level in filler tank drops about 2 inches, and the AST level remain the same @ almost full.

Then I try to do the "bubble in filler" test. I start my car with both caps open. When the car is getting warm, the coolant level in the filler rise and eventually at the top and begin to spill. Becaz of this, I shut down my car, however the level keeps on rising and some coolant spill off, but no bubble and foaming. At the time I shut off my car, the temp gauga is @ "C" mark which is a bit higher than lowest temp.
So I just wondering if I has done the test??? Or I have to wait until the gauge is pointing @ 9???
And Do I have to fill both the filler and AST full with coolant?

And I have smelled the exhuast gas and coolant.. I think they didn't smell the same. After I shut off my car, I found that there's some liquid on the exhaust tip. I has no smell, I think it's water but not coolant.

So do my car still have coolant problem???
I still have my pre-cat on.

Yea, the lights are both on and are supposed to be on at ACC, but I was getting the "buzzer" sound and the temp gauge would jump up, to near the top. But after starting it, it went back down and everything was fine. Mine pressure tested fine externally, and apparently internally as well. The thing that I was saying, is that on cooldown, since u noticed your overflow tank was 4 ticks above full, indicates that your system is pulling air back into the system instead of coolant, and is essentially displacing the coolant with air. The system is supposed to heat up when u run (obviously), and doing so makes the molecules expand. As this is too much coolant for the system to handle, the extra coolant is pushed through the top of the AST cap pressure set to I believe 13 psi and into the overflow, which is normal. On cooldown after shutting off, the molecules shrink, and a vacuum situation is created, granted your system has no leaks (even pinhole leaks will prevent this from occuring, or at least reduce the vacuums efficiency). The coolant that was initially pushed out from the heat is then drawn back into the system. If you have a small leak, then air is pulled in instead (bad), and the excess coolant remains in the overflow, and also explains the reason that your low coolant light comes on, due to the air that has been pulled in, instead of coolant. Sorry if that was hard to follow. :D

The AST cap is a pressure cap, and the filler neck cap is a no pressure cap, and just keeps a seal on the neck to keep coolant from spilling out. The filler neck cap should look like a metal cap with "ears" on it, with a rubber ring underneath the cap, and thats it. The AST cap is circular, and if you look at the bottom of it, it should have what the filler neck cap has, and an extra "Pressure cap" which is essentially an extra rubber ring that is spring loaded. I'm not sure about this, but I believe that you are only supposed to take off the filler neck cap and start it, to do that test. Since the ast cap is supposed to have pressure, the overflow of the coolant from the ast is what its supposed to do, and removing this pressure hold is going to make it overflow out of the AST. To burp it, just wait till its cold, and add coolant to the filler neck and the ast until its as full as u can get it, then repeat. Sometimes unplugging the TB hoses seems to help. And the smoke should smell heavily sweet, and some say it smells like maple syrup, and it should be cloud or pillow-like in appearance if its coolant. The water at the end of your exhaust is most likely condensation boiling off the cats.

OK, i just checked out
when car is cool, coolant level is 4 marks below F in the reservoir. When engine is hot, it goes to 4 marks above F, sometimes even higher.

And i think the previous owner has messed up with the electrical stuff when he installed the greddy turbo timer.
Now, when i turn the key to ACC, nothing is on expect for the tape player. when turn to ON without crank the engine, both the light of water and oil gauge is on, and the water gauge is pointing lowest temp.

And my water temp gauge has never rise more than the pic I attached.
so I think i probably didn;t overheat my engine hopefully...

Boiling sound was gone after remove the both the filler and AST caps. But I am such a paranoid guys, I always afraid I will overheat my car. So what should I do beside DP and fan mod?

get a aftermarket water temp gauge asap!

BTW: I find it halarious that you are using the stock gauge to try to figure out if your engine overheated :D

by the time it moves, it too late hahaha :D

The stock temp gauge is about as usefull as a screen door in a submarine.

yeah
yesterday it moved to 915 and stayed there~
and i was so scared , so shut down the car immediately~~

i have seen temps as high as 240 degrees F. and the stock gauge did not even move...

o
shoot~
if i have even hit 240F / 110C
what will happened????

well if it was for really fast and then you cool it down asap, it is probally ok, but if you leave it at that temp... It aint good!

210 is hmmm is getting kinda warm but its ok
220 is emergency zone
240 is omg, i forgot to turn on my fans or something and I'm about to have to shell out 2-5k for a new engine/rebuild
260 is awww crap I need a new engine

After I first purchased my car, I saw the gauge hit 11:00 while I was sitting at a park. I almost sh*t myself and turned the car off.

Then upon restarting a few minutes later, I drove the car home. I have never seen it do that before or since.

I do wonder sometime if it was somehow related to the bad oil pressure gauge that gave me false 0 all the time before I changed out the sender.

ok
my question is what cause rebuild after overheat beside coolant seal breaks????

did you have your fans on?

btw, its your oil sender unit which is bad, try sanding down the contact

I am not sure if the fan had come on or not at that time.
And I have since replaced the OP sender.