JBsZ06

For the past few days I 've noticed my coolant temps higher than usual but figured it was the much hotter temperatures we've been seeing...but today.....

Today .....I'm cruising at 75 mph in sixth gear and the coolant temps are 207 degrees..(usually 192 degrees)

I turn off the a/c and put the defroster on heat.....and it brings the temps down to 198 degrees..

I'm thinking since I put the stock air box on saturday and found out my aftermarket coupling to the maf was letting some air in...I'd run the stock air box for a few days and sure enough the cars running much much better...but hotter...

So this afternoon I put the aftermarket air filter back in and thought....that would resolve the issue...

Low and behold in 15 minutes of around the town driving...

The car is running 243 or 249 degrees coolant...so I quickly turn off the road onto a side street...turn the car off...and park....turn the key just for a D. I .C reading of coolant about 5 minutes later and the D. I. C says....253 degrees...

I'm like holly ****..so

Wait ten to 20 minutes...start the car and then the coolant goes down about 2 degrees every few minutes..

Now the car seems to be running about 217 to 230 degreess for the most part..sometimes down to 208 degrees but the car really used to run 190 degrees pretty much all the time except maybe bumper to bumper traffic..

I could let the car idle now and it settles in at 208 degrees...and then if I drive it rather gently it climbs to 221 degrees..drive it a little harder and the temps climb to 230...

I didn't sit in traffic today so I'm dumbfounded...

No codes in D. I . C either....

Could it be a fuse for the fan blown..(the passenger side one seems to work...I can't see the driverside one so I can't tell.)

Could it be a slipping water pump belt?

Could it be a bad thermostat?

Could it be the water pump?

Could it be worse like a head gasket?

Could it be the tuning? (found the maf connector to air filter was leaking air in...and fixed it...)

What do you guys think? Any insight would be appreciated...

sandking

iTrader: (7)

I would think either the fan(s) or the t-stat. You did check the water level, right?? I just had to ask.

bad0211secws6

iTrader: (6)

(1) did you check the coolant level?(2) look under the front end and make sure your air dam is in place (3) get a test light and check all your fuses(4)start your vehicle after you are atoperating temp have someone increase your rpmto around 2200 rpm until you see both fans operating,if you see both of them working and it still does not cool down you most likely have a stuck t-stat.you can also have autozone scan it for a t-stat code whick i bieleve is a po128.oh one more thing check you coolant mixture and make sure you have an acceptable mixture of coolant and water. hope this helps good luck!!

JoeyGC5

iTrader: (24)

car running, turn on the ac, both fans should run. Like the others said if both fans are running look for a new thermostat and a radiator flush. Why didn't you drop to a lower thermostat with the cam package?

Grimes

iTrader: (3)

i'd bet that it is the thermostat.

zamboxl

iTrader: (1)

easy check, drop ur stat in boiling water if its stuck u'll see it right there.

Xtreme57

iTrader: (6)

thermostat. Autozone $20.

JBsZ06

I have a 178 degree thermostat in the car now and the original stock 192 degree thermostat sitting in the garage..

Coolant level is off maybe a quarter of an inch below full level on tank (with the car still somewhat hot)

Thanks for the advice guys.

JB

jub jub

JB, not much difference between those two stats as far as opening temp is concerned.

I would put the stock stat back in and make sure you burp all the air bubbles out!

JBsZ06

Thanks for the advice guys..

I just checked the car while it was really cool and the expansion tank was down a bit..

fwiw Its under the full cold level. Acutally its about 1/2 inch below the FULL MARK if I took a guess. Coolant level is AT the bottom of the U or L in the word FULL on the plastic tank.

Is this a big deal? Maybe tommorow I'll pick up some coolant and put it in and see if it makes a difference.

What do U think? is that a low level indicating a bigger problem?

frodo84

iTrader: (11)

FWIW, if it's getting hotter when you raise the rpms, I'd suspect that combustion/exhaust heat was getting into the coolant. Any bubbles in the coolant when you look into the radiator while revving the engine? You might want to think about doing a leak down test on it. I had the same situation with another car one time, if I slowed down, the temp went down. If I idled a while, it would get close to normal. More rpm=more heat transfer to the coolant due to a head gasket leak. Just something to think about...

Ferocity02

iTrader: (60)

I don't know if this will help. My car used to run that hot most of the time. It would get up to 245 in traffic. I put in a 160 thermo and lowered the fan settings and it never got above 180.

under_construction

iTrader: (1)

On a C5, check the radiator intake/mouth under the car to see if it has sucked in a plastic bag or paper or something. Happens pretty often, and will make the car run warmer than usual. A good air/water cleanout of that area will help too, it picks up a lot a dirt/crap.

Squintz Palladoris

iTrader: (1)

From the description you gave, it sounds like its doin fine sitting still. But its getting hot while you are driving. Make sure the rad is getting enough air. Sounds like the Fans are working.
Check the coolant at the radiator (not the expansion tank) when its cold. Fill it up with water. Check it again in a couple of days (Cold) and if its low again I would look to a possible leaking head gasket.

Good luck man!
Brad

P Mack

iTrader: (6)

Obvious, but make sure there's no trash stuck to the front of the radiator blocking the airflow.

JBsZ06

Just so I know my downside...worst case scenerio...

How much does it cost to have the head gaskets replaced?

How many hours does the job take?

If I need a head gasket replaced would that be a good time to change out the valve springs? Easier labor ?

Thanks for all the advice guys...

Hope its a thermostat but best to be prepared for the worst case scenerio...

Grimes

iTrader: (3)

Keep it simple first....check the thermostat first...and then worry if that's not it

slowpoke96z28

iTrader: (2)

hopefully its just the thermo stat. if its the head gasket, hopefully you can put some better heads on there