My Thermostat Replacement

Elemino

Dedicated LVC Member
Joined
Feb 27, 2012
Messages
659
Reaction score
2
Location
Dallas, TX
179147_3999804954652_1247984623_n.jpg


So after the LS sat for 4 weeks. I decided to start her up again today to see if I could easily repeat the overheating that made me park it in the first place... After running about 20 minutes this happened. I ordered the replacement thermostat and a new gasket today. The fan ran like crazy, but couldn't cool the car. (Also, not much heat was coming from the radiator) The degas bottle nearly filled to the top with fluid after it got hot. Everything seems to be in running condition, so my next step is to replace the thermostat. $30 for Motorcraft thermostat and gasket doesn't seem bad to me. I hope this is my only issue. I wish I could flush the system as well.
 
It could be many things. DVVC, AUX coolant pump as well.
There's an AUX coolant pump?

How could the DVVC make the car run hot? From what I understand, it only turns the water flow to the heater core off and on.
 
It could be many things. DVVC, AUX coolant pump as well.

Yes, but replacing the thermostat will seem like a success at first since he will bleed the air out that is likely causing the problem. A day or two later, the issue will be back.

Of course, there is a good possibility that the coolant outlet pipe has cracks and will fall apart when the thermostat is changed.

Lastly, it just might really be the thermostat, but most of the time, it is not.
 
There's an AUX coolant pump?

How could the DVVC make the car run hot? From what I understand, it only turns the water flow to the heater core off and on.

Yes, there is. The only way that the DCCV and/or aux pump can cause overheating is if they are leaking. Coolant leaks out when it is hot, and air leaks back in when it cools off. The trapped air then prevents coolant circulation.
 
But my car isn't low on coolant... and as far as I know isn't leaking anything (other than a little oil on the valve covers).
 
Auxiliary Coolant Pump

I found this on the Aux Pump...

http://www.lincolnvscadillac.com/showthread.php?t=70358

didn't know the car had one. Another strange thing I find on here. However, the car has no problem with sending heat to the heater at idle. When it started to overheat on the road I was sitting at a red light. I did the old fashioned Heater at max with all windows down and open to get it home. It had no problems what so ever moving heat to the heater.
 
But my car isn't low on coolant... and as far as I know isn't leaking anything (other than a little oil on the valve covers).

Yeah, I've had that denial too. A small leak won't show up anywhere and you may go several months before it gets low enough to add. The real problem is that air is allowed into the system through the leak. If the leak is big enough, it will also prevent the system from pressurizing.

The degas bottle is a common problem, as is the coolant outlet pipe. Not too far behind those are all the rest of the plastic cooling system parts.

Yes, it could be the thermostat, and you might as well try that first. Unfortunately, the odds are that there will be more too it.
 
I'll keep your advice in mind. But I watched the degas bottle as the car warmed up. It started to fill as well, and then when I shut the car off the fluid level was visibly dropping as it was sucked back into the engine. To me, everything I've seen points to a stuck thermostat. I've also been guilty of over-diagnosing a problem. Sometimes, the problem is exactly what seems to be the most obvious.
 
I'll keep your advice in mind. But I watched the degas bottle as the car warmed up. It started to fill as well, and then when I shut the car off the fluid level was visibly dropping as it was sucked back into the engine. ...

It shouldn't do that. That's a clear sign of trapped air in the cooling system. Normally, you would see an inch or two of coolant level change in the degas bottle, and it would take hours for it to go back down.
 
That's probably right under normal conditions... but the car was over heating when I shut it off. With the thermostat stuck closed, it wont operate normally anyway. Another thing I observed. While I was sitting out there, it sat at normal operating temp for a while. I even reved the engine to 2000 rpm for a while with no change. Then about 5 minutes later, the temp suddenly started rising. To me it sounds like the problem with the thermostat is just beginning. Could be something else, but this is my starting point. I'll know by this weekend.
 
Got the parts in yesterday. $30 for thermostat and gasket isn't bad..

Now if only it would stop raining long enough to install it.

542183_4015315222399_1008355299_n.jpg
 
BTW Joegr, I'll be replacing the DVVC soon anyway. I'll be doing a lot of work on the car over the next couple of months to get it to where it needs to be. Hopefully customizations will start later this year.
 
So I decided to bleed the system today to see if that would fix the over heating issue... It didn't work. The moment I finished the entire proceedure the temperature started shooting up. Sounds to me like its definitely a thermostat issue... and I wasted this evening. Tomorrow thermostat and DCCV replacement.
 
You seem convinced its the thermostat. Its possible, though very rarely is it the cause of your symptoms on this car. Drop your thermostat in some boiling water and see if it opens. I bet you'd still overheat without a thermostat installed (though you can't try this because the t-stat has the o-ring needed to make a seal). Did you replace the degas tank yet? Could be as simple as a bad vent cap not holding the required 16 psi. Look for any drops of coolant that drip down on the top side of the driver front fender liner (where the fuel filter is).
 
Since I was already tearing the engine apart I decided to tackle both jobs at the same time. DCCV wasn't so hard to replace. It was a :q:q:q:qing mess, but it wasn't so hard... as long as you have the hose clamp pliers, and a few 1/4" extensions...

The problem turned out to be the thermostat housing itself. One of the plastic tabs that holds the thermostat in place broke, preventing the thermostat from being able to open properly. From where I found the plastic piece, it looks like it had jammed the thing close. The thermostat is still good, but I will replace it anyway since I already have one and the engine is torn apart. Problem is now, I don't have a housing, and I'm sitting here without a way to go get one.
 
will the housing close up without leaking? Can you get t-stat in? It may not have to be perfectly centered as long as the o-ring seals.
post a pic, might be able to hack it together temporarily to get you going...
 
Turns out I was wrong about the thermostat. I went back and examined it... and yea its locked up. Wouldn't even budge with me using pliers. I suspect it may be what broke the housing. My dad is on the way out here so we can go to the Ford dealership to get a housing. ($57)

* My car has been sitting for 2 months (out of the 4 we've owned it) with this problem. I can't wait to have it back. Even with its quirks, its a very fun car to drive, and I miss it dearly... *

598804_4074054010832_578134941_n.jpg
 
Another cheap design brought to you by Ford... and another problem I wouldn't have if it was made out of metal... I've been running into a lot of those issues lately on the LS and my Navi.
 
glad you are not stuck and have a ride. Yeah, there's no o-ring on the gen 2 t-stat (unless you removed it). I still can't really tell if its open or closed there.
 
Is this the part that broke?

My initial leak was here:

garbage.jpg


LVC-1-watermark.jpg
 

Members online

No members online now.
Back
Top