jj71787

Hello,

I asked this question on another forum but wanted to ask here as well.

The temp gauge on my car goes all the way to the red and comes back down when driving. it fluctuates a lot while driivng but stays high. There is no smoke. Which someone said would only occur if I had a leak.

There is no smoke from the tailpipes as well.

The heat still works, and there is water in the resivor and readiator.

Mercier

iTrader: (15)

What vehicle and drivetrain? Are your fans running? That sounds like your fans are not coming on. When you drive, air is forced through the radiator and come cooling occurs. When stopped, if the fans don't turn on, no air flows and it will overheat.

jj71787

It's a 99 camaro z28.

The fans are running because when I shut the car off you can still hear them spinning.

Mercier

iTrader: (15)

Can you verify this by idling with the hood open? I am a "show me" guy and I'd like to know that both are running. I don't know that sound alone will prove that. It is possible the thermostat or water pump are having issues as well. Have you ever done a proper cooling system flush? You said "water" in the radiator. Do you mean coolant, or is there literally plain water in there?

jj71787

I have not done it with the hood open. I will do that.
I've never had the system flushed.

It's plain water in the radiator

LS6427

iTrader: (2)

Go buy a new Coolant Temp Sensor.......

If you want to verify that you are NOT actually getting hot.....next time you see the temp gauge go into the red, pull over immediately, pop the hood, and lay your hand on top of the intake. If your temp actually gets into the red and its actually 250-260*F.....you cannot keep your hand on your intake for more than 1-2 seconds without burning your skin badly. Your shock tower will also be too hot to touch at all without getting burned.
If you are running at normal 185-205*F temps....you can keep your hand on the intake no problem.

.

ben husen

also put some coolant into the system instead of just water and make sure its full not low

Mercier

iTrader: (15)

If you've been running plain water it is likely a good idea to flush the thing before you put a proper cooling mix in there. Coolant isn't just anti-freeze. It lubricates your water pump and minimizes corrosion in you cooling system...it's all metal you know?

jj71787

I took it to pep boys and the guy did a carbon monoxide test. He said it was supposed to turn yellow and it didn't. Then he said it's a blown head gasket just by looking at it.
He said there's no pressure in the hose.

2kgtp

Just because there is no pressure in the hose doesnt mean the headgaskets are junk. Could be a faulty radiator cap

warriorpluto

iTrader: (2)

Exactly. I had the same problem op had earlier this year. Turned out it was the radiator cap. I'd replace that first

JakeFusion

iTrader: (7)

I'd do a coolant flush, put a 50/50 mix of distilled water and coolant, and change the radiator cap. Also, you might want to verify the coolant is as hot as the temp gauge is saying. It could be a faulty sensor. But if you don't feel any heat in the radiator hose, then you need to address that first with the flush and new cap and then check the sensor.

jj71787

I put a new radiator cap because it was leaking. I changed the coolant temp sensor and coolant level sensor

JakeFusion

iTrader: (7)

Is your overflow tank leaking? I had that problem on another car. Had a small hole there and it'd basically drain itself down.

Is the coolant level remaining the same? If you have air in the system, it'll overheat too.

LLLosingit

iTrader: (4)

Antifreeze does not lubricate the water pump, They run a seal to stop water from entering the bearing itself. Water pump bearings are greased/sealed for the life of the bearing.
Straight water has better cooling properties than a 50/50 mix, You did get the corrosion inhibitor right but you can buy an additive to add to the water like "Water Wetter" to take care of that.

Have you checked the thermostat? It's easy to do, We verify ours by putting it in a pan of water and slowly bringing the water to a boil while reading the temperature and watching the thermostat open. Most are close to the advertised temperature but I have seen some new thermostats be off -+ 15*

my406cid

Does your car have the hard plastic flap that hangs below the core support? That flap forces a it up into the rad/condenser. Th op said it overheats goin down the road. If this air dam is missing it Wil do exactly what it is doing.bottom breathers as they are called need this dam to keep cool at road speed

jj71787

The coolant is remaining the same. I don't see any leak. It could be air. Couldn't that be why the water was bubbling

jj71787

I haven't checked the thermostat yet. I'm going to call a friend who is a mechanic and see what he says before we start taking things apart