head gasket?

[hutch]

for the past couple days i've noticed a knocking sound whenever i accelerate. its usually only really noticable at higher speeds (above 40mph). its been running a little hot lately. i had a coolant leak from the lower radiator hose about a week ago. i replaced the hose and it hasn't leaked badly since. last night after i got home it looked like the coolant was bubbling out from the lower radiator hose. i tightened the clamp and it seemed fine. today i noticed the cooland bubbling in the over flow tank after a short drive. a few days ago on my way to work a spark plug popped out. it didn't seem to have anything wrong with it so i threaded it back in and i haven't had any problems with it since. so now for the questions... is all this stuff related? what kind of tests can i do to find out whats wrong? does it sound like a blown head gasket/ warped head or possibly something worse? any ideas or suggestions would be greatly appreciated.

 

[skinner]

for the past couple days i've noticed a knocking sound whenever i accelerate. its usually only really noticable at higher speeds (above 40mph). its been running a little hot lately. i had a coolant leak from the lower radiator hose about a week ago. i replaced the hose and it hasn't leaked badly since. last night after i got home it looked like the coolant was bubbling out from the lower radiator hose. i tightened the clamp and it seemed fine. today i noticed the cooland bubbling in the over flow tank after a short drive. a few days ago on my way to work a spark plug popped out. it didn't seem to have anything wrong with it so i threaded it back in and i haven't had any problems with it since. so now for the questions... is all this stuff related? what kind of tests can i do to find out whats wrong? does it sound like a blown head gasket/ warped head or possibly something worse? any ideas or suggestions would be greatly appreciated.

Do a chemical test at the radiator that tests for exhaust in the coolant. Mine went negative, but i tore it apart anyways.
All was fine.
Don't make the same mistake .

 

[Wicked_Sludge]

the spark plug and coolant leaks are probably unrelated (i would double check the other 5 plugs to make sure someone didnt leave them loose).

bubbling in the coolant reservoir can be cause by several different things. it could be as simple as air in the system from when you changed the radiator hose, to a bad radiator cap, to a blown head gasket. you can do a chemical test like skinner suggested...but your more likely to find a shop equipped with a coolant pressure tester which will also give you a definitive yes-no on a blown head gasket.

 

[hutch]

alright thanks guys. i changed the coolant and got a fresh 50/50 mix in it and its running good now. its leaking again tho. it looks like its coming from around the lower radiator hose where it connects to the engine. but it doesnt look like it leaking out of the actual hose. it looks like its coming from just above that. any ideas on where it could be coming from in that general area?