burping/flushing cooling system and leakdown/comp test

[Maniak87]

i am trying to figure out if i am begining to blow a head gasket or if i just have an air bubble in the coolant system. how do i go about burping the system? i would also like to flush the whole system but unsure as to how to do it myself.

i guess it would be a good idea to do a compression/leakdown test before i start taking it apart to replace the head gaskets. although, i was told that doing these tests may not help in showing that the head gasket is blown.

i do not have any traces off coolant in the oil or oil in the coolant reservoir. this problem arose at the track when i made some paces. after the pass, the temp shot up to 240-250. coolant was spewing out of the resevoir. i was thinking maybe i overfilled the system? i was able to drive the car home with no issues. the motor runs fine and stays at about 190 when cruising.

 

[El_Diablo]

do a pressure test on the cooling system, this is a sure way to see if you have a constant leak (sometimes leaks occur when temps get to hot or the motor is cold and they will seal themselves back up once they get to certain temps or pressures)

you could just have a pressure issue to where the cap wasnt on tight.....

also, are you wanting to do a chemical flush or a water pressure flush? chemical flushes are pretty easy, just follow the directions, for a water pressure flush you'll want to disconnect a radiator hose and put a hose, ideally feed with distilled water, into one of the openings and start the water flow.... allow the water to pour out until you no longer see and deposits or coolant, you may also want to try multiple flush points, after that just drain everything once again and reconnect everything and close the petcock, then just add your new coolant/water mixture or straight water if you wish

 

[idro]

If you're talking about burping your radiator but i think i got an idea what your talkin about. Just take your cap off and let it run after you have filled it with nice new green joojoo from napa. It will run for about 5 mins or so then it will kind of blurp and coolant will come out and you will lose some. Shut down your car and your radiator will be a considerable amount low. Fill that up and then you're good to go. I dunno if thats what you are talking about or not.

And like the above poster said, it might be something simple instead of something overly complicated like a faulty radiator cap or something. I doubt you have a cracked block or something of the sort cause you would know it. Atleast i did when it happened to me

 

[Maniak87]

If you're talking about burping your radiator but i think i got an idea what your talkin about. Just take your cap off and let it run after you have filled it with nice new green joojoo from napa. It will run for about 5 mins or so then it will kind of blurp and coolant will come out and you will lose some. Shut down your car and your radiator will be a considerable amount low. Fill that up and then you're good to go. I dunno if thats what you are talking about or not.

And like the above poster said, it might be something simple instead of something overly complicated like a faulty radiator cap or something. I doubt you have a cracked block or something of the sort cause you would know it. Atleast i did when it happened to me

yea i did that but nothing really happend when i ran it with the cap off for a little while. maybe i just need to do it a couple times. thing that makes me think its a headgasket is the fact that it seems to overheat whenever it sees boost. im going to get a leakdown/compression test done.

 

[94kingcbra]

maybe the thermostat got stuck closed somehow..? I would replace it with a balanced thermostat, cheap and atleast you know that it is not that if it ever does it again, good luck

 

[Maniak87]

did the leakdown test and sure enough, when i was on cylinder #3 coolant shot up out of the radiator, looks like i have a blown head gasket.

the compression check didnt show this though.

 

[2slo95fiveoh]

did the leakdown test and sure enough, when i was on cylinder #3 coolant shot up out of the radiator, looks like i have a blown head gasket.

the compression check didnt show this though.

well at least you found your problem. coming from someone who has performed a head gasket already, i would recommend
replacing anything that is out, thermostat, all gaskets, etc.. and be sure to get your heads crack checked and resurfaced.

 

[El_Diablo]

wouldn't be a bad time to check/replace the valve seals either, minimum have them magnafluxed and surfaced as the above poster noted


a compression test is a momentary rise in pressure and is not designed to show those sort of issues, the leakdown tests and coolant pressure tests make spotting leaks a lot easier just due to the fact that your building a constant pressure and holding it