Heater Core Bypass

[jimmyducati]

My '10 SHO did this last night in the drive through, not only zero heat but it was pretty cold air coming out. As soon as I took off it was HOT. Ill try topping off the coolant today, should  I just pour some in the overflow?

[BiGMaC]

If you top off the coolant and the problem happens again...... and again the coolant needs a top off --> You might check for the seal leaking from the T-stat install.  Aniother member found this to be a problem.

[BigPelo]

If you top off the coolant and the problem happens again...... and again the coolant needs a top off --> You might check for the seal leaking from the T-stat install.  Aniother member found this to be a problem.

Yes but it was right after a 170F thermostat install on my 2013.

My '10 SHO did this last night in the drive through, not only zero heat but it was pretty cold air coming out. As soon as I took off it was HOT. Ill try topping off the coolant today, should  I just pour some in the overflow?

Don't forget to put 50/50 water with concentrated coolant, yes the overflow tank.

[DJE624]

Just in case, check for a small leak right here in the picture.  I had a drip there.  The dealer put a clamp on it for me.

[SHO-Pa]

I also have this issue with my 2011 but I also have 2 questions -
1) My 11 has the green coolant. Am I correct in that the good ol' Prestone 50/50 is fine (or is it a special FoMoCo blend as I found out with the orange stuff in my 07 Expy)?
2) Am I correct in that if I just add it to the recovery tank it won't "burp" the system?

[DJE624]

I'm not totally sure but I thought all the newer cars had the orange coolant. 

If you fill to the cold line and then run the car at temperature, let it cool off, refill if necessary and run at temp again, it should burp. 

Edit-Run the heater at full blast too.

[BiGMaC]

I also have this issue with my 2011 but I also have 2 questions -
1) My 11 has the green coolant. Am I correct in that the good ol' Prestone 50/50 is fine (or is it a special FoMoCo blend as I found out with the orange stuff in my 07 Expy)?
2) Am I correct in that if I just add it to the recovery tank it won't "burp" the system?

My dealership advised "don't mix types and don't mix colors"... If there's nothing in the reservoir you might drain a couple of teaspoons from the radiator petcock to check when the engine is cold.... then mix the antifreeze... with WP lube... to desired dilution and fill as DJ recommended... It will burp itself 'cuz the air rises

[SHO-Pa]

Interestingly enough, my older Expy has the orange stuff (only available at FoMoCo I am told) but the 11 SHO has the green. It even has a "NO ORANGE STUFF" sticker on the recovery tank.

I was surprised that the newer vehicle still had the green stuff although it seems the 2013s have orange. Not sure about 2012s.

[DJE624]

I'm 99.9 % sure I have orange in my 12.  I'd have to go look now to be positive! LOL  I've checked the level before and never gave it a thought. 

Edit-If it was green, I'm sure I would have noticed.

[dalum]

A lot of cars won't "burp" themselves.  The heater core can be the highest point and air gets trapped in there.  The pro's use a tool to pull a vacuum in the system after draining the radiator.  Then this vacuum pulls the new antifreeze in filling the system without trapped air pockets.

You can do this at home with an air compressor but you have to take care of the coolant properly.  I used this system http://amzn.com/B0002SRH5G but I don't recommend it.  The way it is designed you end up putting the air in the hose between the valve and the new coolant back into the system.  This http://amzn.com/B000IHK1VI model is setup the right way.  You pull a vacuum on the system and the hose to new coolant so no air gets sucked back in.  Have a hose clamp ready to close off the hose to the overflow container.  The tool didn't cover that gap when I did my wife's GrandPrix.

There is also back flushing the coolant system.  But since the only thing that probably has s*** in it is the heater core I do that by itself.  Disconnect both lines going to the heater core at the engine side.  You can rig something up but i used this http://amzn.com/B0045CUMVG connected to a garden hose.  Plug it in one side of the heater core and run clean water through it until you're happy.  Then plug it into the other side and repeat. 

[6gun]

For some reason I cannot get to the TSB.  Can someone summarize what it says to do, or cut/paste?

TIA!

[SHOdded]

Unfortunately the site is now restricted, so I cannot access it either

[BiGMaC]

Unfortunately the site is now restricted, so I cannot access it either

A little scary I think

[SHOdded]

It's like someone goes through the security logs, says "oh, someone tried to access this page, let's restrict it" and then changes permissions.  Maybe they finally did it sitewide, because there were holes in between earlier.

[BiGMaC]

Typical... Some are "insider secrets" and some are just plain to save money by waiting to see if we actually break down before it's fixed.

I believe we should be ENTITLED to any TSB that is applicable to the car we own.  Part of proactive maintenance.