leak at temp sensor??

[geospider]

discovered this today.
Once up to temp and pressure,found a leak near the temp sensor. I replaced this since it didn;t work the PO had a bunch of plastic type "stuff" around the base of it that I had to remove to get old one out and new one in.
Now I see that was some kind of sealer that they also had on the top of the head toward the back of motor.
I am hoping I need to tighten the sensor, but I don't imagine they need to be very tight.
there is a certain leak: see pic in the area. can't tell if crack in top of head or at sensor. seems a strange place for a crack.
http://imgur.com/V7o0N7j

geo

[DRUMMOND]

There appears to be some crud at the bottom of the sensor, may be take it off and inspect it closer, clean the area up then use thread sealant when installing it see what happens after that. May be leaking from the heater hose connection also seems like a lot of rusty coolant
May want to change coolant.

[klweimer]

Also possible your head gasket is leaking up through the head bolts and coolant is collecting around sensor. Do you see any coolant pooling in spark plug wells? If not, then probably not that. Before chasing down leaks, I would try to clean up the top of the head as much as possible. Pressure washer? Car wash?
Kirk

[geospider]

Thanks to both of you.
The interesting, or worrying part is: when I replaced the sensor, I had to break off some kind of almost plastic type stuff the PO had around the base of it. So, a bit worried there is a crack somewhere around that area. the last bit of that stuff was just to the rear of the sensor: when pulled that off, the steam/leak you see in the pic really got going.
the only water collecting around spark plugs are the back 2, since the leak blows that way.
the coolant is fine, new, since I did a flush., replaced the radiator and T stat. the old one with rusty water blew all over.
any specific thread sealant you recommend?

geo

[klweimer]

My favorite is Permatex #2. Totally old school, but works well.
Kirk

[geospider]

Thanks. I like old school
I degrease and clean. then try this. hoping this is all it is.
anyone ever tried the sealer products: like Irontite (I know not the correct fix, but might work for a bit)

[kmoses]

I have used Oatey #31229 "Great White" pipe joint compound with PTFE and it works great for sealing threaded fittings on the head that come in contact with anti-freez. It withstands up to 10,000 psi on liquids and from -50°F to 500°F temps. You can get it from Low's for about $4. Be sure to get the correct temp. range (read the back of the tube), Oatey also has another pipe sealant that is only good for 200°F and you don't want that. I have used this on the temp. sending unit and the water fitting at the back of the head that feeds the heater with no leaks.

[geospider]

worse than ever imagined.
Ever see something like this? a hole in the head! It was held together with J-B weld

http://imgur.com/ME4BnEJ

thoughts??

Geo

[geospider]

For those who saw the previous post. there was a hole in the top of the head.

fortunately I had another head from PO: valve job done.
finally ready to install.

https://imgur.com/4iACLN5
https://imgur.com/4iACLN5

hope these pics work.
wish I could just load the pics without the link

[Odoyle]

Don't throw the damaged head out, that hole can be repaired via TIG welding.

[geospider]

won't throw it out. but was told that there may not be much aluminum left to fix. the temp sensor hole/threads are practically gone at one point.

I'll prob bring it to the machine shop just to see what he says.