05 LS Keeps Overheating Slowly

[xarlock667]

Hello all, I am working on a FINE Lincoln LS from 05, and I cannot figure out why the hells she keeps overheating! I have changed the thermostat 2 times, the engine head temp sensor works fine (I use it with my OBDII sensor) and I have bled the system of air. I just cannot figure what is causing the engine to slowly overheat like that.

When I turn the car on, I sit and wait patiently. The temp climbs initially about 3 degrees every 5-10 seconds to about 180F. Then the temp picks up a tiny bit to about 2-3 degrees every 3 seconds up to 228F at which time I turn the car off to prevent damage. I have, as stated, bled the system. I fill the engine at the radiator with the cap off the DEGAS bottle until it backs up into the Degas. Then I cap the Degas and start the engine and add whatever else will fit. I make sure the heater is on and blowing hard, then I open the bleeder screw on hose that sits to the side of the Degas bottle. When I get a fairly steady stream, I replace the screw. No dice, it just keeps getting slowly hotter until it overheats.

I am open to thoughts and ideas, HELP!

 

[joegr]

Okay, I am going to bet that you are not an exception to what most of the rest of us have been through.
You have to replace all the plastic cooling system parts, and you have to bleed exactly (to the letter) by the factory fill and bleed procedure.

There is no way to fill at the radiator. Did you really mean the engine fill (on top of the engine, not the radiator)?

Do you have a V6 or a V8?
Is your electric fan working correctly? (Should be very loud when overheating.)

If the V8, then:
http://www.lincolnvscadillac.com/forum/showthread.php?91092-GenII-LS8-Cooling-System-Overhaul
http://deneau.info/ls/s6x~us~en~file=s6x33004.htm~gen~ref.htm#extract_142

 

[BrianDye]

Sounds like you need to do the plastic component overhaul.

The plastic components in the cooling system degrade and crack, including the degas bottle and it lets air into the system (and/or leaks coolant out).

I can't offer much more info right now, but some members who have a lot more experience with it will chime in soon. It's 99.9% of the problems when someone posts about an LS overheating.

 

[don-ohio]

Probably his electric fan not coming on.He didn't mention it roaring, which it should be loud enough to notice. don-ohio ^)

 

[joegr]

Electric fan failure seems to be very rare...

 

[don-ohio]

Fan probably isn't failing, just bad fuse or controls. don-ohio ^)

 

[joegr]

Fan probably isn't failing, just bad fuse or controls. don-ohio ^)

Once again, your superior mis-knowledge triumps...
I'll bow out. I'm sure you've got it from here.

 

[don-ohio]

OH,no Joe! Touchy...touchy! I can't carry your drinkin water and I KNOW it! I just wanted the guy to affirm whether he had heard the fan or not. don-ohio ^)

 

[xarlock667]

Hello all again!
Here is some info I forgot to include, the fan DOES come on, I neglected to mention that. I have seen no leaks of coolant from anywhere except the Degas when it overheats, and from the engine coolant cap on the front of the engine. That is where I fill it from.

So here is what I am going to try:
I am going to check the coolant levels and see where I am at. I looked up the bleeding procedure before and that is what I followed when I bled it before, but I will do it again. If it turns out poorly, then I will check the fans and see what their performance is like then I will look into repairing or replacing the plastics.

 

[joegr]

There is only one fan.
Normally, you won't see any leaks, as in liquid coolant. If you know what to look for, you can see the residue on the parts where the coolant leaks. The cracks are microscopic. Just search this site for the hundreds of owner experiences with this.

 

[elephantrider]

look around for residue like this... white flaky goodness...

 

[xarlock667]

So! I went and rechecked the engine coolant and degas levels. LOW. I looked and found that my shiny new thermostat is leaking all over the damned place due to a faulty seal. CRAP. So now I have that to fix too. I guess I will get back to you when I get some work done, thanks for all the help so far!

 

[joegr]

Maybe the seal, but more common is for the plastic to be degraded and start to crumble there, almost like it rots away.
Also, note that some on here have had trouble with the Dorman thermostat assembly. I strongly recommend all Motorcraft parts for the cooling system.

 

[elephantrider]

don't be afraid to use some rtv around the mating faces !

 

[1LoudLS]

for what its worth, air will leak back in before you will ever see any liquid leaking out...

once it gets bad enough for liquid to leak out, its more of a quick overheat cause all of the coolant has ran right out.

 

[xarlock667]

OK, replaced the thermostat housing and the plastic plumbing behind it. It still runs over 225F, BUT it does not overheat anymore! (Still hotter than I like it though!) Any thoughts on how to get the temperature down any lower, say to around 190?

 

[joegr]

190 is too low and not good for engine wear.
Cleaning the outside of the radiator may get you to 200-215.
You did you Motorcraft parts, right? If you used Dorman, then you are doing good to get it down to 225.

 

[xarlock667]

What is the proper engine temperature range?

 

[grizzlyls]

I watched mine (gen 1 hydraulic fan) go from a low 210 to max 230 one day after I DIY upper pipe and I was going to my mech in Pasadena thinking I had more issues. The fan never kicked in like it would with high heat. This was 35ish speeds city traffic. It wasnt at 230 long, that was after a long hill going up. Average range was probably 215 to 225, mostly sitting in the teens.