Name that part! (Leaking coolant at the top of the engine)

[BrianDye]

So dropping my coworker off, I noticed a little smoke billowing from under the hood. Popped the hood, and noticed a good bit of coolant puddled on the top
Of the engine, and running down very close to the manifold on the pass side.

Got home, and it seems as if this part is where it's coming from. Bear with me here, as I try my best to describe it. It's right behind the thermostat housing, looks as if the coolant temp sensor is mounted into this metal piece and some hoses are connected to it as well.

Im guessing it's this part, because the coolant is all around it, and you can see the residue where coolant has leaked and dried up around it.

What exactly is that called, it looks easy enough to replace. Few bolts and disconnect the sensor and noses and reinstall in new part?

Thanks in advance!

 

[Maniak]

Are you sure it isn't the thermostat housing itself that is leaking (it's common). The housing is plastic and is 2 pieces.. Well, actually 3 BUT 2 pieces are glued together and it eventually leaks at the seam on the bottom part.

I haven't done it on an explorer but the 4.0 sohc motor in the mustang (2006) has the same (very similar) thermostat housing and all you do you the Mustang is take the throttle body off so the housing will come up..

If it is the thermostat housing you really have 2 choices. Buy another plastic set from Amazon.com or the Dealer (I'd stick with motorcraft) OR buy a metal one. [MENTION=209654]thermohousing[/MENTION] on here sells the metal housing on Amazon and on Ebay...

~Mark

 

[BrianDye]

I'll have to double check tomorrow afternoon when it's light outside again but I swear it seemed like the part behind the thermostat.

The TB on m 4.0 is plenty enough behind the thermostat housing and the part I'm talking about as well, to be able to remove/access it.

 

[swshawaii]

+2 on the lower t-stat housing. Search the Gen 2/3 sub forums, one of the most common failures with the 4.0 SOHC.
If you're still not certain after inspecting, an almost fail safe method for detecting leaks is renting a cooling system pressure test kit. Most larger auto parts stores will loan them with a fully refundable deposit upon return. Call around.

 

[BrianDye]

I'm gonna assume the metal housing is a lot more expensive if the plastic one is about $70 at Autozone

Autozone doesn't have Motorcraft, but I've never had an issue with the Dorman brand. Have members had issues when going away from OEM on this piece? The specs say it's built better than the OEM design...

 

[BrianDye]

Found it on Rockauto for $45 shipped. Gonna look up that metal replacement you mentioned before I jump on that though.

 

[BrianDye]

Sweet baby Jesus!

Is this the metal one you're talking about, Maniak? As much as I'd love the upgrade, I'll have to stick with the plastic replacement for now. Believe it has a lifetime warranty so if I ever have the issue again it can be replaced for free.

 

[Maniak]

Yup, that's the metal one. The Motorcraft Plastic one you can buy as a replacement has the same design (glued together part) that will fail again later. the metal part wasn't available when I needed to replace ours.

I paid about $100 for the upper & lower parts (motorcraft) with o-rings from amazon. I wasn't going to try a cheaper (dorman) part that would probably be even worse (Dorman is pretty much cheap parts, although they do seem to work)...

It all comes down to how long are you keeping the vehicle... I'm expecting our thermostat housing to fail again soon as we have over 300k miles on our '06 SOHC motor... I haven't decided if we are going metal or plastic when it fails again as I don't think we will keep the car another 100k+ miles.

~Mark

 

[BrianDye]

Well within a year or two, I plan on making this a secondary mud/fun toy truck. I want to find a nice black on black leather V8 when I pay this one off.

I ordered the one on RA for $50 with next day shipping. It has a new thermostat, o rings and clips with it. We'll see how it works. Can't really afford the metal one right now, otherwise I would have. Gonna have to drop some money in the front end very soon. When my AWD kicks in, I'm hearing some funny noises. (Or in 4 high when turning)

 

[BrianDye]

Replaced the housing today, seems to have solved the problem.

Old one looked to be leaking from 3/4's of that plastic seal. Terrible design, but if this one lasts at least 20k or so miles I'll be happy. Description says better quality than oem.