[jimpamm]

Ok good day everyone let me start by saying I have a 2005 deville DTS she has 78,567 miles on her owned since 2010 bought with 58,324 oil change every 3000 she is a well maintained car ok so start by had no heat in car it was summer so didn't do anything right away she ran fine about two weeks ago she started to get hotter than usual not over heating but line before while driving it would go back to middle up an down few days than boom she just over heated well got hot and the message came across shut car to hot
So take to mechanics the change thermostat ok good for day or two then hot again so bring back they tell me water pump still no good so they radiator is no good still no good then he said he changed the antifreeze from orange to green and it works and it did got car back had heat ran good temp stood in middle all good two weeks now overheating again so the hose from the thermostat housing and the one above it where hot and hard the overflow tank i twisted the top a little under a lot of pressure oh and when i stopped antifreeze was also shooting out the over flow hose ok this is the kicker the antifreeze from the over flow spillage was cold like cold cold dont get it can someone HELP PLEASE i am at the end with just drop a little over 2gs for the repairs mechanic says my engine is blown could it be !!!

 

[Byrdman]

First step always, is pull codes to see what is stored. Post the codes AND definitions here. Keep in mind that only powertrain/emissions codes will trip the SES light.

 

[Submariner409]

Your engine is not "blown". There's something wrong with either the water pump drive system or there are air locks in the heater core or block/head coolant circuits. Your "mechanic" is simply throwing parts and coolant at it in the hope something sticks.

Cold/cool coolant in the surge tank says there's a coolant circulation problem - the purge line should flow a small steady stream into the surge tank - that tank sits on a T-fitting at the bottom and is designed to use the airspace at the tank top to create system pressure as the coolant heats and expands. System pressure is what raises the coolant boil point and assures "solid" coolant to the water pump as well as increases the metal-to-coolant heat transfer ability.

Study the several cooling system stickies in the Engines; Northstar forum. As long as you've been a member - you should be intimately familiar with the Northstar cooling system and its foibles.

Punctuation, anyone?

 

[Byrdman]

Punctuation, anyone?

at least it wasn't all CAPS.

 

[AAIIIC]

Moved from the '04-07 CTS-V forum to the correct DTS forum. Not sure why my fellow mods didn't manage to do that 12 days ago, but hopefully you'll get some responses now.

 

[Byrdman]

Not sure why my fellow mods didn't manage to do that 12 days ago, but hopefully you'll get some responses now.

isn't it obvious? we're a bunch of slackers who should be on here 24/7 to catch these errors. Calling out your fellow mods in public is bad form.

 

[Submariner409]

The reason some threads - originally posted in the wrong vehicle/model forum - do not get moved right away is because some of us get into CF via the New Posts page. We see a question that we're familiar with, open the thread - read and answer without noticing that a Deville is posted in CTS-V.

 

[Jake Turner]

Now back to the issue at hand.....
Are both heater hoses going into the firewall the same temp? They should be. If not, heater core could be plugged or restricted.
Like Sub said, check for good flow from the purge line at the tank.