P0128 code - Coolant Thermostat

[QCTLG]

Hoping someone can help me find this part so I can try to fix this myself

I've gotten this code "P0128" and doing some googling found this site with what I seeing as being the possible culprit to the problem.
http://www.hyundaioemparts.com/auto...t/cooling-system-scat/?part_number=255003c130

It's part no.6 but I cannot locate it on my car.
Can someone please help me out?

Thanks

P.S.
My symptom is The thermostat gauge doesn't go up and am having problems with not enough heat coming from the vents inside the car.

 

[OneFunGenesis]

Ah. This is a bit tricky. They are mostly on top of the engine on most cars, but this one looks to be on bottom. The thermostat will be INSIDE part 9 mated to part 7. I will give a visual example below

That is for a Nissan, but you are looking for a similar looking housing with 2 bolts. Coolant WILL flow out just an FYI in case you wanna do this with the car warm or on a nice floor. Let me know if you need any further help

OFG

 

[scottdk]

OP, Have you had your coolant changed recently? I ask because these symptoms besides a thermostat as you mentioned would also be air in the cooling system. Could be bad hose, or bad hose connection too.

Culprit is most likely your thermostat though.

 

[mikec]

Follow the large hoses from the radiator. One of them will end at the thermostat housing. The diagram you linked doesn't exactly match my 2009 4.6 V8, nor does it match the pics in the factory service manual for the V8. On my car, the hose from the top/passenger side corner of the radiator looks like it heads to the "water inlet" part (item #8 in the lower diagram of your link) which is on the very top/front of my engine, underneath the big hose feeding the throttle body. You have to remove some of the plastic air ductwork and possibly the throttle body to get this stuff apart. The factory service manual calls this the "water temperature control assembly."

Note too that the engine bits in this area changed during the production run (which is why some item numbers are duplicated in the parts diagram you linked) so you need to use the build date of your car (should be on a metal plate on the door jamb) to know which version matches your car.

Some coolant WILL spill when you try to open this stuff up. Drain a gallon or two from the radiator first. Some coolant though will be trapped in the rubber hose even if the radiator itself is almost empty... just the nature of the beast. So you are going to have a minor spill no matter what. Wrap the "water inlet" parts with absorbent rags/paper towels as you loosen and remove it to catch the bulk of this stuff. It doesn't smell bad... but whatever spills onto the engine will burn and stink if it's not washed off. I try to limit the spillage with rags...

mike c.

 

[QCTLG]

Guys,

thanks soo much for your help...
It's too complicated for me to tackle this, so I'm gonna have the dealer do the repair.

Scott,
FYI, I did not change the coolant.

 

[Bill K]

Check for low coolant.

 

[hy-klasse]

I'm actually dealing with this issue right now! I ordered up a new thermostat housing from Rock Auto (Auto 7 3110115 (311-0115)). The 4.6s use a combined housing/thermostat/coolant distribution unit, which is about $110USD from the dealership. Doesn't seem too bad, just as simple as draining enough coolant, removing covers/hoses, removing the throttle body, and it's right there. I attached files from All Data that shows how to replace it.

I say doesn't look too bad, but anything is a pain this time of year if you don't have a warm dry place to work...

 

[dmitriylm]

I'm actually dealing with this issue right now! I ordered up a new thermostat housing from Rock Auto (Auto 7 3110115 (311-0115)). The 4.6s use a combined housing/thermostat/coolant distribution unit, which is about $110USD from the dealership. Doesn't seem too bad, just as simple as draining enough coolant, removing covers/hoses, removing the throttle body, and it's right there. I attached files from All Data that shows how to replace it.

I say doesn't look too bad, but anything is a pain this time of year if you don't have a warm dry place to work...

Looks like its right under the throttle body. There are some components to get out of the way but overall doesn't look like a horrible pain.