JBsZ06

Car was overheating and so far I've had a tech replace the waterpump/thermostat/and belt.

With the stock thermostat the first week the car was running about 200 degrees coolant most of the time...

Then a week later the car was running like 220 degrees.

Today the car is running 240 degrees...and this afternoon the cars running 260 degrees....

The tech said the flow through the radiator is 15lbs...and the coolant was good. I suggested flushing the system and he said it wasn't necessary...

My tuner said he pressure tested the car and it was ok...

The oils looking good and its not loosing any coolant.

Nothing is blocking the radiator.

The tech said the fans were working and I can see the high speed fan working when the temps get higher(over 200 or somewhere about there)

So what do you guys think?

A sensor? a fuse? A head gasket? Maybe the belt is stretching in two weeks and thats why its starting to overheat again? My tech thought the belt was the cause originally but we changed out the water pump and thermostat with new units cause I didn't have the time to mess around..

Of course I'm now having the same problem again...

Any guesses or insight would be appreciated..

santino04

I would have guessed the same as you on the flush. Possibly a blocked passage I would think, but your tech said hes got flow. ??? Thats wierd, why would it run hot if you have the right thermostat in a new water pump and what not, the thermostat isnt electronically controlled Let me ask you this are you going off the stock gauge reading, because they arent so accurate and also yours may be toast. Your coolant temp sensor could be starting to go out. Id investigate the gauge or sensor, you may want to hook up a new quality aftermarket gauge. Your probably not even running hot at all and youve just blown all that cash. Hope you find it GOOD LUCK

One more thing came to mind, hopefully your not running real real lean. Youd be heating up that engine pretty quick that way, and possibly the cooling system cant handle it. Investigate more thoroughly so you dont wreck that block or whole engine in that case.

slowpoke96z28

iTrader: (2)

what santino04 said is possible. use a non-contact thermometer on the radiator hoses to see if it is actually getting this hot. also make sure nothing is blocking the radiator or got sandwiched between the condenser and radiator. if the A/C is working fine there probably isn't an airflow problem, though.

JBsZ06

Originally the tuner said that with the heat sensor....the temps on one side of the thermostat were 198 and the other side was like 239 degrees leading him to believe the thermostat was bad...

While I was having the thermostat replaced I had the water pump and belt swapped out. I didn't want to deal with any more cooling issues..

Low and behold two weeks later I'm back at the same starting point..

Could it be a bearing or something in the 25% reduction pully causing the belt to slip again? after two weeks it got slowly higher and higher?

Why would the car do that?

(not sure about the flow numbers as it showed the radiator at 15lbs/whatever that means) and I am going off the stock digital guage that shows up on the Vettes D.I.C.

The car hit 260 degrees coolant and went into coolant overtemp mode...(protects the motor?)

camrsz

iTrader: (4)

was there any work done or mods added before it started to over heat the first time?
does it cool down any if you turn your heat on when it gets hot?
how long does it run before it starts to overheat? Is it on the highway, city driving ect..

Richie Carbone

iTrader: (3)

Did you make sure the system was free of air???

There could be an air pocket trapped in the system causing the high coolant temps.

slowpoke96z28

iTrader: (2)

only other thing would be a flush, fill, and bleed the system, after that its time to make sure that every thing is correct with the water pump install. and make sure the guy tests the cap along with the rest of the system.

shouldaboughttheZ

iTrader: (8)

if that doesn't fix it, looks like you might need a radiator.
My mother n laws car did the samething. It started to overheat, and they took it in. They swapped fan motors, thermostat, water pump. Still overheated. They ended up replacing the radiator and low and behold it was fixed.

JBsZ06

I didn't do any mods before the problem but I did put the stock air box on the car....for a week as I was cleaning the aftermarket version I had for quite some time...

I noticed the coolant temps were getting higher after about a week I put the aftermarket kit back on....

Problem still continued to get worse...

I assumed it was coincidence....

The fluid in the reserve tank looks about the same as it has since the completion of the waterpump/thermostat/belt installation....

I'd say within twenty minutes its over the top ..240 range...

Highway it drops a little but still way to high which concerns me as that would lead to the fact its not a fan problem...(easier fix)

Radiator Cap at 15 lbs...(from tech)

Pressure test would show if it was the radiator????

And would smoke blow out back of car if exhaust side of head gasket was leaking? (i have no smoking out back)


I appreciate all your suggestions...

shouldaboughttheZ

iTrader: (8)

If WHITE smoke was blowing out back of the car, that would be a sign of headgasket problem. Its good you don't have it.

Did he bleed the system of air properly?

camrsz

iTrader: (4)

I do not think a flush will fix it.The coolant flush machine we use only has about the same amount of presure as most coolant systems. Sounds like an air pocket.

ninobrn99

iTrader: (8)

loosen the front coolant lines till you see all the bubbles go away. that should clear it up.

robertbartsch

Yeh - what that guy said up there.... probably an air bubble problem or radiator blocakage issue.....

;;; also take the air box off and double check the space between the raditor and AC condensor for leaves, plastic bags, etc. Check it from under the car too...

JBsZ06

Here's the update:

Put in new coolant sensor as there was a 20 or 30 degree descrepancy from actual temps..

The new belts are the right tension..(checked that)

The radiator is taking coolant in and cooling it 25 to 30 degrees from bottom to top..

The caps good..

The coolant systems has new coolant in it and was blead properly......

The compression test showed 175 lbs with less than a 2% variance in cylinders...

The cars running its fuel trims are right on the money between 1 and 2 %

The radiator fins look clean..Its flowing and disapating heat properly...

The thermostats good..

The waterpumps new...and the dam car is still overheating...today..

On the highway? 199 degrees which is fine with stock thermostat..

Around town...it starts to climb...and if I run 4000 rpms with a/c on or off.... (or there abouts) through neighborhood streets at between 35 and 40 mph....The coolant temps shoot to 241 degrees and within? three minutes..they are up to 252 degrees again..Fwiw...its 88 degrees outside today..

As I parked the car in the garage this afternoon where the coolant hit 252 degrees as I got home.....I faintly smelled that sweet smell...(coolant?) (probably just from replacing the coolant as we examined the thermostat...)

Its not requiring any new coolant...The level of coolant over the past two weeks has remained the same...

I'm at a loss at this point...so any other ideas would be appreciated..

UnleashedBeast

iTrader: (2)

Well, when I change my coolant to insure I get most of the air out of the system before I seal it here is what I do.

Park the car on an incline with the front of the car parked uphill. Fill the radiator with coolant while the engine is running and watch the air bubble out the fill point. Do this and contine to top off the radiator as the thermo opens and takes coolant into the engine. After a few minutes when the radiator is full and you see no more air bubbles your done. Sometimes I return to the incline after a few days and redo the procedure to see if I can purge any more air out.

JBsZ06

Thanks for the air purg tips...I'll double check...

I have a question...Could it be related to the A/c condensor going bad?

A/c is strong but...

8pm drive off...with a/c on full blast.
83 degrees outside.

Driving about 3 to 4 thousand rpm at 35 or 40 mph in second gear..

8:15 pm 215 degrees coolant
8:20 pm 217 degrees coolant
8:21 pm 225 degrees coolant
8:22 pm 230 degrees coolant
8:23 pm 243 degrees coolant (jumped from 240 to 243 real fast)

Idle car turn off a/c

8:25pm 234 degrees coolant
8:26pm 232 degrees coolant
8:27pm 226 degrees coolant
8:28pm 225 degrees coolant
8:29pm 221 degrees coolant
8:30pm 219 degrees coolant
8:31pm 217 degrees coolant
8:32pm 217 degrees coolant
8"33pm 214 degrees coolant
8:34pm 212 degrees coolant
8:35pm 210 degrees coolant
-------------------------------------------

Drive with A/c off

3 to 4000 rpm at 35 or 40mph in second gear.

8:45pm 219 degrees coolant
8:47pm 225 degrees coolant
8:53pm 219degrees coolant

----------------

Do a few drag like starts then idle:

8:55pm 221 degrees coolant
8:56pm 219 degrees coolant
8:57pm 217 degrees coolant
8:59pm 214 degrees coolant

then

pull in to garage 214 degrees coolant.(still 83 degrees outside)

Turn off car...then turn key on but not start car:

221 degrees coolant.

Maybe its related to the A/c being on?

Maybe take the a/c belt off and then see but I couldn't get the car over 225 with A/c off...

What do U guys think? Possible?


JB

robertbartsch

Suggestion:

Go to a local Jiffy-Boob and have them pressure clean your cooling system for baout $65. Alternatively, ripe out your radiator and have it tested at a local radiator shop.

oange ss

iTrader: (50)

maybe A/C fan not coming on

'Trust'

iTrader: (24)

have u tried bleeding the air out of the system? I had the same problem, it'd be fine on the highway, but on city driving it'd over heat, it took me about 3 times of bleeding the system to get all the air out, i actually had to jack up the passenger side to get the cap at the highest most point possible, i have a funnel with a spill proof cap that i fill the radiator with, then fill the funnel about a 1/3 and the bubbles come up through it. per time i'd run the car to operating temp, keep it going for another 5 mins, then shut it off, let it cool down, and do the same a couple more times. i repeated this 2 times at later dates, and the problem is gone

camrsz

iTrader: (4)

If your a/c compressor is going going bad it can cause the engine to overheat do to causeing the engine to work harder. Do your rpms drop alot when you turn the a/c on?