OMG She overheated out of the blue!

[bigjayzway]

Well I took the STS out on her monthly highway run.

I went 45 miles and turned around to come home, when I noticed the temp. rising.

I thought nothing of it, and kept driving, and next thing I know, she is shutting off the A/C and telling me to idle the engine.

I pulled over, and opened the hood. WOW she let off some steam.

This happened 3 more times before I got home, and 3 gallons of Dexcool later.

Now I don't see any dexcool in the oil, and visa versa.

Could this be a simple thermostat?

Or am I looking at a head gasket?

[PAUL T]

Well I took the STS out on her monthly highway run.

I went 45 miles and turned around to come home, when I noticed the temp. rising.

I thought nothing of it, and kept driving, and next thing I know, she is shutting off the A/C and telling me to idle the engine.

I pulled over, and opened the hood. WOW she let off some steam.

This happened 3 more times before I got home, and 3 gallons of Dexcool later.

Now I don't see any dexcool in the oil, and visa versa.

Could this be a simple thermostat?

Or am I looking at a head gasket?

I would check for leaks first. Then check or replace the thermostat. Check for a collapsed lower hose, I had put a new lower hose on and it did not have the spring in it like the old one and it caused my deville to overheat. See if the radiator is dirty on the outside and clean it out. Next check to see if the cooling fans are working. I would not even consider head gaskets at this point.

[Ranger]

Do you see any external leaks?

[BodybyFisher]

I had a thermostat go once and it acted just like yours just did. Check the stat. How many miles? Checked the water pump belt?

[bigjayzway]

Hey Mike.

Thanks for the quick response.

I only see the coolant coming out of the res. cap, and if I shut it down it comes out more.

I do not see any other leaks anywhere.

There are 300658 kms on the car.

The thermostat is about a year or so old. But I did have issues with it before. It seemed that this one ran a little hotter than it should.

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

I added it to the lower rad hose, and not the tank, but still see it floating in the tank.

I am going to try to clean the system tomorrow.

I will drain the system, and add nothing but water, and then drain it again.

I will then replace the thermostat and add the tabs and dex cool.

Is there anythig alse I should try?

I am at wits end here and praying for the best.

This couldn't of hit me at a worse time.

[BodybyFisher]

Hey Mike.

Thanks for the quick response.

I only see the coolant coming out of the res. cap, and if I shut it down it comes out more.

I do not see any other leaks anywhere.

There are 300658 kms on the car.

The thermostat is about a year or so old. But I did have issues with it before. It seemed that this one ran a little hotter than it should.

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

I added it to the lower rad hose, and not the tank, but still see it floating in the tank.

I am going to try to clean the system tomorrow.

I will drain the system, and add nothing but water, and then drain it again.

I will then replace the thermostat and add the tabs and dex cool.

Is there anythig alse I should try?

I am at wits end here and praying for the best.

This couldn't of hit me at a worse time.

Make sure the purge line pisses coolant when you take the hose off the tank, you could have air in the system if its blocked. I am hoping for the best Jay

[Ranger]

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

What kind of Barsleaks did you use? Bars makes the tabs.

[bigjayzway]

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

What kind of Barsleaks did you use? Bars makes the tabs.

I used the liquid stuff.......NASTY!

[bigjayzway]

Hey Mike.

Thanks for the quick response.

I only see the coolant coming out of the res. cap, and if I shut it down it comes out more.

I do not see any other leaks anywhere.

There are 300658 kms on the car.

The thermostat is about a year or so old. But I did have issues with it before. It seemed that this one ran a little hotter than it should.

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

I added it to the lower rad hose, and not the tank, but still see it floating in the tank.

I am going to try to clean the system tomorrow.

I will drain the system, and add nothing but water, and then drain it again.

I will then replace the thermostat and add the tabs and dex cool.

Is there anythig alse I should try?

I am at wits end here and praying for the best.

This couldn't of hit me at a worse time.

Make sure the purge line pisses coolant when you take the hose off the tank, you could have air in the system if its blocked. I am hoping for the best Jay

Just to make sure I know what I am looking for the right hose.

Is the purge line the small one on the left side of the tank?

[bigjayzway]

Hey Mike.

Thanks for the quick response.

I only see the coolant coming out of the res. cap, and if I shut it down it comes out more.

I do not see any other leaks anywhere.

There are 300658 kms on the car.

The thermostat is about a year or so old. But I did have issues with it before. It seemed that this one ran a little hotter than it should.

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

I added it to the lower rad hose, and not the tank, but still see it floating in the tank.

I am going to try to clean the system tomorrow.

I will drain the system, and add nothing but water, and then drain it again.

I will then replace the thermostat and add the tabs and dex cool.

Is there anythig alse I should try?

I am at wits end here and praying for the best.

This couldn't of hit me at a worse time.

Make sure the purge line pisses coolant when you take the hose off the tank, you could have air in the system if its blocked. I am hoping for the best Jay

Just to make sure I know what I am looking for the right hose.

Is the purge line the small one on the left side of the tank near the top?

[BodybyFisher]

Yes, I believe it is, looking over the fender, it faces the radiator if I recall

[bigjayzway]

Yes, I believe it is, looking over the fender, it faces the radiator if I recall

I will check all the hoses and connections tomorrow, and let you know.

Thanks again.

[adallak]

It is a good idea to change the oil and thermostat after an engine overheats.

[Regis]

Could it just need a new surge tank cap? Had an incident awhile back where I lost a lot of coolant through the cap. A $10 fix.

[Ranger]

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

What kind of Barsleaks did you use? Bars makes the tabs.

I used the liquid stuff.......NASTY!

Wrong stuff. That may be your problem. Check that purge line. Maybe flush the radiator as well.

[bigjayzway]

The last time I had an issue, I didn't have the tabs for the coolant, so I used bars leak, and have had nothing but problems since.

What kind of Barsleaks did you use? Bars makes the tabs.

I used the liquid stuff.......NASTY!

Wrong stuff. That may be your problem. Check that purge line. Maybe flush the radiator as well.

Well I drained all the coolant, and refilled with 50/50 Dex Cool.

I changed the thermostat, and washed the purge tank.

The nasty stuff that came out was unreal.

I have had the car running for the last hour in the driveway, and no overheating yet.

I did also add the tabs from GM this time. I added 4 of them.

I will advise later to let you all know what happenes.

Keeping EVERYTHING crossed on this one.

Thanks again to all you guys, you are the best.

[BodybyFisher]

Did you check to see if the purge line was pissing coolant? Pull the hose an verify that. I hope its fixed, Mike

[bigjayzway]

Did you check to see if the purge line was pissing coolant? Pull the hose an verify that. I hope its fixed, Mike

Yes indeed it is, and stupid me has the 2nd degree burn to prove it....LOL

I am noticing after 2 hours of running the car, the overflow cap is letting out small amounts of steam.

I guess the next step is to get another cap?

There was small amounts of antifreeze on the tank from around the cap, after taking her for a run.

The temp. went to one line after the halfway point, and then came down right away. Is this normal?

[Ranger]

Might be normal if there was air trapped in the system, then again, steam from the cap is never a good sign. Keep an eye on it and see if it settles down.

Next step could either be a new cap or a coolant exhaust gas test.

[bigjayzway]

Might be normal if there was air trapped in the system, then again, steam from the cap is never a good sign. Keep an eye on it and see if it settles down.

Next step could either be a new cap or a coolant exhaust gas test.

Would the gas test indicate head gasket?

It seems to get hotter when I get back from a drive.

It is not a lot of steam, but enough to see it coming out.

Also seems like the purge line is bubbling inside?

I added the coolant to the tank when I filled the system, and the tabs to the hose right in front of the thermostat.

Am I suppose to do anything else to burp the system?

[BodybyFisher]

Did you check to see if the purge line was pissing coolant? Pull the hose an verify that. I hope its fixed, Mike

Yes indeed it is, and stupid me has the 2nd degree burn to prove it....LOL

I am noticing after 2 hours of running the car, the overflow cap is letting out small amounts of steam.

I guess the next step is to get another cap?

There was small amounts of antifreeze on the tank from around the cap, after taking her for a run.

The temp. went to one line after the halfway point, and then came down right away. Is this normal?

I would take no chances and just replace it, I think Regis took that angle... Good Luck, I think you might have beat this. Ranging temps as Ranger stated would be a sign of air. Turn it off and let it settle. Typically when I open the cooling system, I fill it, warm it up and let it sit till it cools.

[bigjayzway]

Did you check to see if the purge line was pissing coolant? Pull the hose an verify that. I hope its fixed, Mike

Yes indeed it is, and stupid me has the 2nd degree burn to prove it....LOL

I am noticing after 2 hours of running the car, the overflow cap is letting out small amounts of steam.

I guess the next step is to get another cap?

There was small amounts of antifreeze on the tank from around the cap, after taking her for a run.

The temp. went to one line after the halfway point, and then came down right away. Is this normal?

I would take no chances and just replace it, I think Regis took that angle... Good Luck, I think you might have beat this. Ranging temps as Ranger stated would be a sign of air. Turn it off and let it settle. Typically when I open the cooling system, I fill it, warm it up and let it sit till it cools.

I am letting her cool now, and will see if it needs more coolant.

I will get another cap tomorrow.

Am I correct to assume it is not to be filled past the full cold mark??????

[Ranger]

Would the gas test indicate head gasket?

Yes.

It is not a lot of steam, but enough to see it coming out.

Also seems like the purge line is bubbling inside?

I don't like the sound of this.

Am I suppose to do anything else to burp the system?

Nope. It is self purging.

[bigjayzway]

Well I changed the rad cap.

So far so good.

They didn't have a 15lbs one, but they did have a 16lbs one.

I put it on, and not a problem as of yet.

Looks good so far.

Thanks to all that helped.

Jay

[JasonA]

The OE cap on my STS is actually an 18 PSI cap.