Why cut the thermostat?

[Digital_Dad]

First off Hello All! It's nice to be here.

My DIL just bought a 2011 Ford Expedition Limited (which means I now repair it).
So far I have cleaned the MAF, throttle body, K&N air filter. Changed the front brake pads, front pass brake hose, taillight bulbs, oil & filter, thermostat & oring and had to replace the blower motor resistor and plug(it caught fire at the gas station on the way home from buying the truck). Still need to fix the transaxle shift motor code issue and two Air conditioning actuators - one in the front and one in the rear(clicking when starting the truck).

The question I have is when I pulled the thermostat the old one was cut and gutted? The housing was in there but all the internals were gone, I know it was cut because I can see the angle grinder or cut off wheel marks where someone cut the bottom sides to remove the spring. Why would someone do that?

 

[99WhiteC5Coupe]

First off Hello All! It's nice to be here.

My DIL just bought a 2011 Ford Expedition Limited (which means I now repair it).
So far I have cleaned the MAF, throttle body, K&N air filter. Changed the front brake pads, front pass brake hose, taillight bulbs, oil & filter, thermostat & oring and had to replace the blower motor resistor and plug(it caught fire at the gas station on the way home from buying the truck). Still need to fix the transaxle shift motor code issue and two Air conditioning actuators - one in the front and one in the rear(clicking when starting the truck).

The question I have is when I pulled the thermostat the old one was cut and gutted? The housing was in there but all the internals were gone, I know it was cut because I can see the angle grinder or cut off wheel marks where someone cut the bottom sides to remove the spring. Why would someone do that?

Because the person that did that did not have another thermostat or didn’t want to spend $10 for a new one.

 

[JasonH]

Probably thought free flow would improve cooling. Maybe there was a cooling issue.

 

[bodabdan]

Possibilities-
Someone was fighting an overheating issue and was trying to avoid radiator, fan, or water pump replacement.

Previous owner thought it would run better if it ran cooler, like the Quadrajet days.

Used car lot "fixed" it for pennies instead of actually fixing it.

Someone hated the idea of a heater blowing warm air.

When you get it back together be alert in case there was a bad component that's still bad. Don't let it bite you.

 

[Digital_Dad]

I will keep an eye on it all this week. I still have a few bugs to work out. The rear parking aid, transaxle shift motor, and air conditioner actuators in front and back click when it first starts, and the DVD headrests have no power to them. So I have more to do to get it sorted out.

 

[JimR_TN]

I don’t think anyone has bought an older Expedition and not had to replace an AC actuator. I replaced 3 on my 2007 last year when I got it. Luckily it is inexpensive and mostly easy.

 

[Digital_Dad]

I don’t think anyone has bought an older Expedition and not had to replace an AC actuator. I replaced 3 on my 2007 last year when I got it. Luckily it is inexpensive and mostly easy.

How hard is it to replace the rear one? All that plastic looks like it is going to be very hard to remove in order to get to it

 

[GlennSullivan]

The rear is not bad, there are videos on youtube that goes through the process.

2015 Ford Expedition Rear Mode Door Actuator Change.

Tips to changing a rear mode door actuator. My particular car was making a loud clicking noise and also blowing hot air in the third row seating whether the ...

www.youtube.com

 

[Timo2824]

I'd take that k&n filter off and throw it in the trash. Back when I was a mechanic those brought me lots of engine rebuilds. Hard to beat the pleated paper filters.

 

[purevw]

I'd take that k&n filter off and throw it in the trash. Back when I was a mechanic those brought me lots of engine rebuilds. Hard to beat the pleated paper filters.

I tend to agree about the K&N filter. Chances are that the oil in the filter is why you had to clean the MAF sensor and throttle body. I have several K&Ns on older vehicles and every one leaves an oily residue downstream of the filter. Please note that it is not from using excessive oil.

 

[GlennSullivan]

Ive run K&N on all of my high performance cars for the last 20 years and the secret is to not oil them at all. Use them as you would any ordinary paper filter - one that flows 1.5 times as much air as paper, and throw them away when they are dirty. Don’t believe the BS about the “forever filter”.

 

[callwill]

When you say "transaxle shift motor" do you mean the transfer case shift motor?

 

[Timo2824]

Ive run K&N on all of my high performance cars for the last 20 years and the secret is to not oil them at all. Use them as you would any ordinary paper filter - one that flows 1.5 times as much air as paper, and throw them away when they are dirty. Don’t believe the BS about the “forever filter”.

This is the mentality that brought me lots of engines! If you only drive around in town it's probably fine, but throw in some sand/silica dust and it'll tear up valve seats and cylinder walls. If it's got a turbo it'll eat the blades down just like a boat prop that's seen too many beaches.

 

[bodabdan]

Not to hijack the thread, but any filter that flows more is letting larger stuff through.
It's physics.
Air filters and cold air intakes have great marketing teams.