What is this part called?

[keleko17]

I'm leaking coolant from where the thermostat mounts.

I want to call it the top of the engine block. If you stick your finger down below and to the right of the thermostat mounts, that is where the pin hole is. Basically straight through the coolant temperature sensor (I guess that is what it is.)

I'm driving a 1999 - 4.0 OHV.

 

[koda2000]

I may be wrong (never had a 4.0L OHV) but I think that's part of the timing cover.

 

[AP9]

Believe it or not, that whole cast aluminum assembly is the lower intake manifold.

Unless, you mean what is behind & underneath that, in which case I would agree with koda2000.

 

[koda2000]

If it's the front of the intake manifold you're referring to, it's the front of this whole thing (front not shown, but you can see the sensor and hose connections).

http://www.rockauto.com/catalog/moreinfo.php?pk=5927862&cc=1354553&jnid=544&jpid=1

 

[ranger7ltr]

Take a look and let us know...

Here is a pic of the lower intake and front of the engine... Can you point out where the coolant is coming from???

 

[keleko17]

Basically I have to stick my finger along side the lower intake, on the driver's side, as far as my finger can reach. It is on the side, and towards the bottom of what I can reach.

I took the thermostat out, and tried to feel for something from the inside, and was unsuccessful. It must be a hairline crack or pin hole. Anyone have a creative way of JB welding something like this rather than replacing the intake? I am in the process of shopping for a replacement car, I just need a couple more weeks to find the one I want

 

[koda2000]

I suggest you get a small bottle of K-Seal. I've had extremely good luck with this product on leaks much worse than yours. Most auto parts stores carry it. Its expensive for the size of the small bottle ($15-$17) but it really works.

 

[keleko17]

I have tried Bars Leak with no luck. (this time) I'm pretty sure this has been an old problem that has gotten worse. But it is to the point now that I have to do something. It won't hold coolant now. I have to refill it every other day, about 1.5 gallons.

 

[keleko17]

What about some sort of paint on style product? If I take the thermostat out, I might not be able to feel the hole / Crack, but it is surely there. I should be able to get an artist brush in there to "paint " a repair.

 

[ranger7ltr]

Interesting spot for a leak...

I would try JB Weld...Use a fairly rough sandpaper inside and outside to clean the area and then mix it up and apply... Let dry for a day or so and it should hold...

I used that on a radiator that my metal cut a couple of tubes in and pulled a vacuum on the radiator to draw the JB Weld in...A day later and it held for more than 15 years.. So far on another vehicle...

Good luck with that although replacing the lower intake is not that difficult...

 

[keleko17]

For those following, I applied JB Weld today. I used the original cold weld and smeared it inside the thermostat hole, and then use steel stick on the outside, and hence coated the steel stick with cold weld. I will update you tomorrow afternoon if it holds.

 

[keleko17]

JB Weld seems to be holding. I used both the original 2 part epoxy on the inside, and then the SteelStik on the outside, and then covered the SteelStik with the 2 part epoxy