Jump to content
CaddyInfo Cadillac Forum

Change thermostat now Coolant is boling & leaking


Recommended Posts

Good morning,

On Sat. I changed the thermostat on my 2002 seville sls. I bought it from Auto Zone. After removing the old one..i compared them to one an other and the one from auto zone is completely different but I was assuming that’s because its not an original thermostat from GM…anyways …My problem started last night when I had to drive my son back home..i noticed a lil change on the temperature gauge..but it wasn’t that abnormal…

I looked under the car and I was leaking some coolant and it was coming from the top radiator. And I could hear the water boiling…but the temperature gauge never showed overheating…..

I’m assuming its because of the thermostat… the car was running perfect until Sunday..when I noticed coolant leaking and herd the water boiling from the reservoir..

Any body has any ideas?? Maybe the thermostat has something to do with all this??????

Link to comment
Share on other sites


Good morning,

On Sat. I changed the thermostat on my 2002 seville sls. I bought it from Auto Zone. After removing the old one..i compared them to one an other and the one from auto zone is completely different but I was assuming that’s because its not an original thermostat from GM…anyways …My problem started last night when I had to drive my son back home..i noticed a lil change on the temperature gauge..but it wasn’t that abnormal…

I looked under the car and I was leaking some coolant and it was coming from the top radiator. And I could hear the water boiling…but the temperature gauge never showed overheating…..

I’m assuming its because of the thermostat… the car was running perfect until Sunday..when I noticed coolant leaking and herd the water boiling from the reservoir..

Any body has any ideas?? Maybe the thermostat has something to do with all this??????

First, I would make sure the thermostat has not been installed upside down. The side with spring should be oriented towards the engine not towards the radiator hose.

The saddest thing in life is wasted talent

Link to comment
Share on other sites

Good morning,

On Sat. I changed the thermostat on my 2002 seville sls. I bought it from Auto Zone. After removing the old one..i compared them to one an other and the one from auto zone is completely different but I was assuming that’s because its not an original thermostat from GM…anyways …My problem started last night when I had to drive my son back home..i noticed a lil change on the temperature gauge..but it wasn’t that abnormal…

I looked under the car and I was leaking some coolant and it was coming from the top radiator. And I could hear the water boiling…but the temperature gauge never showed overheating…..

I’m assuming its because of the thermostat… the car was running perfect until Sunday..when I noticed coolant leaking and herd the water boiling from the reservoir..

Any body has any ideas?? Maybe the thermostat has something to do with all this??????

First, I would make sure the thermostat has not been installed upside down. The side with spring should be oriented towards the engine not towards the radiator hose.

yes when i installed it i made sure it was put in the same way the old one was...for some reason im thinking its the thermostat that causing all this....the brand was DURALAST i believe from auto zone...

Link to comment
Share on other sites

Its possible that your purge line is clogged and not allowing AIR to get out of your cooling system when you refilled it.. Check the purge line and the 'bolt with a hole in it' to be sure its clear.

DO NOT blow air into the purge line, to dislodge any possible clog.

Remove the hose near the throttle body, then remove the bolt and check for a clog, you could first pull the hose off the coolant tank and see if coolant flows from it when the engine idles (cool engine only), coolant should flow from the hose.

It is also possible that you have a bad stat, I personally wouldnt use any stat but and AC delco

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Good morning,

On Sat. I changed the thermostat on my 2002 seville sls. I bought it from Auto Zone. After removing the old one..i compared them to one an other and the one from auto zone is completely different but I was assuming that’s because its not an original thermostat from GM…anyways …My problem started last night when I had to drive my son back home..i noticed a lil change on the temperature gauge..but it wasn’t that abnormal…

I looked under the car and I was leaking some coolant and it was coming from the top radiator. And I could hear the water boiling…but the temperature gauge never showed overheating…..

I’m assuming its because of the thermostat… the car was running perfect until Sunday..when I noticed coolant leaking and herd the water boiling from the reservoir..

Any body has any ideas?? Maybe the thermostat has something to do with all this??????

First, I would make sure the thermostat has not been installed upside down. The side with spring should be oriented towards the engine not towards the radiator hose.

yes when i installed it i made sure it was put in the same way the old one was...for some reason im thinking its the thermostat that causing all this....the brand was DURALAST i believe from auto zone...

If nothing was wrong with old thermostat, I would put it back with new o-ring and take the new one back to Idiotzone. :)

The saddest thing in life is wasted talent

Link to comment
Share on other sites

The OEM stat has a LONG TAIL on it so that it reaches into the coolant flow area, you must replace it with one that is physically the same

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

There are several (many) engine parts on these cars than must be replaced with OEM parts and the cooling system thermostat is one of those.

Aftermarket parts are designed to be as generic as possible to fit the same (made in China) replacement part on as many applications as possible.

That approach does not work so well for the Northstar engine. And you are living proof.

Now I have to ask why you thought thermostat replacement was called for?

Jim

Drive your car.

Use your cell phone.

CHOOSE ONE !

Link to comment
Share on other sites

The OEM stat has a LONG TAIL on it so that it reaches into the coolant flow area, you must replace it with one that is physically the same

Mike, you figured it out right. The spring of the replacement stat does not get dip enough into coolant.

The saddest thing in life is wasted talent

Link to comment
Share on other sites

ok guys im back and thank you all for all the feedback i really do a ppreciate it.

I just got back from Adelco and i bought another thermostat and i compared the one from adelco and the old one i had take off and they finally match.they both look the same..and yes the one from autozone for some reason looks thiner and longer where it has the spring or whatever...im hoping to change it 1st thing tomorrow morning..and i hope all my troubles go away...

i will let every one else how it goes tomorrow morning..

can i still return the thermostat i got from autozone...??? even though i used it already??

Link to comment
Share on other sites

can i still return the thermostat i got from autozone...??? even though i used it already??

I think so, because THEY sold you a part which was supposed to work on your engine, but it apparently has not. You may ask for a credit instead of refund.

The saddest thing in life is wasted talent

Link to comment
Share on other sites

Good Morning,

so i changed the thermostat this morning and everything seem to be fine now..but ughh..for some reason im leaking water from the radiator. Now this is my question" can the radiator get messed up if the water was boiling but my car never overheated??????

for some reason my problem started after i put the thermostat from autozone, the car ran fine for about 25-30 miles. when i dropped off my son i checked to see if my car was leaking water..and it was from the radiator..and i herd the water boling fromt he resevoir....so im thinking since the water was super hot and was boling it messed up my radiator... is this possible??

im just soo fustrated..lol....

Link to comment
Share on other sites

Good Morning,

so i changed the thermostat this morning and everything seem to be fine now..but ughh..for some reason im leaking water from the radiator. Now this is my question" can the radiator get messed up if the water was boiling but my car never overheated??????

for some reason my problem started after i put the thermostat from autozone, the car ran fine for about 25-30 miles. when i dropped off my son i checked to see if my car was leaking water..and it was from the radiator..and i herd the water boling fromt he resevoir....so im thinking since the water was super hot and was boling it messed up my radiator... is this possible??

im just soo fustrated..lol....

Yes, the end tanks are plastic, if you boiled you raised the pressure and temp. Your radiator was probably on the edge of failing anyway, you didnt ruin a good radiator. How bad is it leaking?, do you normally use the cooling supplement?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Good Morning,

so i changed the thermostat this morning and everything seem to be fine now..but ughh..for some reason im leaking water from the radiator. Now this is my question" can the radiator get messed up if the water was boiling but my car never overheated??????

for some reason my problem started after i put the thermostat from autozone, the car ran fine for about 25-30 miles. when i dropped off my son i checked to see if my car was leaking water..and it was from the radiator..and i herd the water boling fromt he resevoir....so im thinking since the water was super hot and was boling it messed up my radiator... is this possible??

im just soo fustrated..lol....

Yes, the end tanks are plastic, if you boiled you raised the pressure and temp. Your radiator was probably on the edge of failing anyway, you didnt ruin a good radiator. How bad is it leaking?, do you normally use the cooling supplement?

Well when my car is running i can see it leaking..but its not excessive...and after i turn it off...it leaks for about 5 minutes maybe and then it stops...but when it leaks u can see drops falling..its not like it squearting out...

cooling supplement??

Link to comment
Share on other sites

Cooling supplement was mandatory till about 2000 if I recall, they are tablets that get put into the cooling system (upper hose NOT into the coolant tank) and they were good for minimizing and preventing leaks at the seals, etc

I was thinking that when you drained your coolant to do the stat, that you flushed out the cooling supplement with it. If you are seeing dripping, its probably time to change your radiator, look at the end tanks. The end tanks on ALL vehicles these days are plastic, they used to be brass, but brass would react with aluminum. Over time the plastic develops stress cracks, your boilover/boiling might have produced enjoy pressure/heat to do them in.

You might try the GM cooling supplement in the meantime until you can get a new radiator to see if you can slow the leak, crush the tablets and put them into the upper hose

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Cooling supplement was mandatory till about 2000 if I recall, they are tablets that get put into the cooling system (upper hose NOT into the coolant tank) and they were good for minimizing and preventing leaks at the seals, etc

I was thinking that when you drained your coolant to do the stat, that you flushed out the cooling supplement with it. If you are seeing dripping, its probably time to change your radiator, look at the end tanks. The end tanks on ALL vehicles these days are plastic, they used to be brass, but brass would react with aluminum. Over time the plastic develops stress cracks, your boilover/boiling might have produced enjoy pressure/heat to do them in.

You might try the GM cooling supplement in the meantime until you can get a new radiator to see if you can slow the leak, crush the tablets and put them into the upper hose

oh ok i get it now..hehe..well i did get an estimate from the dealer on a radiator and its close to $600 and autozone game me a price of $360 + tax. hmmm thats alot of money lol....so for right now im better off trying the tablets and i pray to god they work...

can i get them from autozone lol or from ac delco?? or it has to be from the dealer???

Link to comment
Share on other sites

Do some calling around we usually get radiators for about $180 to $225

Try www.rockauto.com and www.gmotors.com

You can use aftermarket radiators it is not necessary to go to GM for on, also stay away from autozone, its too commercial along with pepboys, etc

Find a NAPA parts place

Use 5 tablets

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

If it is just the end tanks, a radiator shop could install new end tanks and gaskets for you. If you took out the radiator and brought it in, it would cost less than having the radiator shop do everything.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

Thank you soo much for all of your help. I will definetly put the tablets in this afternoon after work..But defintetly i will check to see where exactly the radiator is leaking from, because like KHE said it might be just the "END TANKS".

AC Delco is selling the end tanks for $50.00..so i will let you guys know what the outcome of all this is.

Thanks again to every one for all your help..

Link to comment
Share on other sites

KHE is correct, IF you do the work yourself you CAN save money, however, by the time they (a shop) R&R the end tanks you might as well buy a new radiator and install it yourself

Find a radiator shop, I have a good one, they talked me OUT of putting on new end tanks and referred me to a business that sells radiators, see if a radiator shop can install the end tanks for you and how much

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Whatever you do, find and fix the leak. The tabs are a band aid and will never give out at an opportune time. You can bet on that.

True, my recommendation was a temporary one till he finds a radiator as I noted, its not for major leaks

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

If it is just the end tanks, a radiator shop could install new end tanks and gaskets for you. If you took out the radiator and brought it in, it would cost less than having the radiator shop do everything.

KHE, I have replaced end tanks on my Seville. Saving was NOT worth the time playing with end tanks. Aftermarket wholemetal radiators are about $150 and they are actually better than OEM. I would NOT recommend anybody messing up with replacing end tanks.

The saddest thing in life is wasted talent

Link to comment
Share on other sites

Good Morning guys,

Well i have good and bad news...Yesturday morning i installed the new thermostat from AC delco and in the afternoon i use the tablets...My radiator is NOT leaking anymore...but last night when i got home from work. i herd water boling, but it wasnt as bad as last time when i had the thermostat from autozone.. even after i turned off my car i could hear water going down the hoses..... any ideas of what it might be now???? UGH if its not one thing is another lol....

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...