loud knocking NEED HELP!!!

[xTSIx]

For prolly the past 2 months now my car has been acting very odd. It used to boost at 16 PSI and now it ranges from 10 all the way down to 3. For awhile now when it builds boost it may go to 10 but then drop to 6 and the car jerks really bad. id like to know what that is. Also, my car for the past like 3 weeks has been reading HOT on the temp gauge and yesterday i replaced the thermostat and it went back to normal. Well tonight i was going down the road and it was on HOT again. I pulled over and checked to see if it was actually hot and it didnt seem so. I wasn't gonna chance driving back to college an hour away like that so i headed home and about 3 blocks from my house it shut off. Steam came out under the hood like whoa. I popped the hood and a coolant line had busted so i fixed it quick and started the car. It ran worse than ever. Its puttering around, bogging out, running like a piece of crap. It still wont boost, it jerks around, in putts about and feels like its dead. THe motor was rebuilt i belive about 50,000 miles ago and for some reason my car has no cam positioner and the hole is JB weld shut (should i find on and get it on?) I just need some help so tell me ....
UPDATE:
i switched the coolant line this morning and started it and let it run for awhiel
it would idle at 1500 rpm and then drop to 800 rpm and repeat. I started down the road and it was driving really shitty. It had nothing to it, it would bog out and sputter unless it was at a high rpm and if it slowed it woudl stall and there is also a REALLY loud knocking or ticking noise from the motor? what may that be?

 

[DSM90AWD]

Possible your head gasket is blown. Check your oil for coolant and coolant for oil.

 

[xTSIx]

so it may just be a head gasket

 

[JessesTalon]

You let your car run "hot" for 3 weeks... If you head gasket hasn't 100% completly disentegrated then I want to know what HG you have cuz I want it!


I'd would have to agree I think your HG is gone and your prolly spilling coolant into the oil and probably your going to be doing a major overhaul/new engine very very soon.

Sorry to hear that, it really sucks! If you can put a 6bolt in next time.

the loud knocking noise... yeah that is probably one of your rods about ready to get thrown through the block.

 

[xTSIx]

It wasn't actaully hot, i replaced the thermostat and it ran normal then till that night

 

[DSM90AWD]

To be safe.. I'd pay a mechanic to perform a leak down test. That way you'll know for sure the condition of your HG. At the minimum check your fluids as I mentioned before.