coolent/radiator problems need help??

[playa69jcr]

in have a 91 gsx the car was fine before i installed a 16g and exhaust manifold the coolant seems to be get really hot at times and shoots out of my over flow tank i i already check and made sure all hose are fine, fans go on , has a coolant additive, water pump is working, the weird thing is at times it doesn't shoot no water out and sometimes it just all shoots out you can just hear the water boil. i drove it yesterday for a whole hour and it was fine then today in just 15 mi. i parked it and it all shoot out it seems be both with the weather at about 60 degrees i can just a imagine what will happen in hotter weather .
???need help???

 

[SOADweskey]

I would always start by checking your thermostat. It's cheap and can cause serious problems like the ones you mentioned if it stops consistently working.

 

[playa69jcr]

how do i check it do i just replace it or is their a way to check it also is their a way to keep my fans running ### i think they dnt always go on when they should but they do go on once in a while

 

[SBstar]

You can wire the fans straight to the battery and install a switch to turn them on and off (what I did). But you might want to consider the possibility of a blown Head gasket. Check the simple things first though. How worn is your coolant kneck cap? I believe they are 13psi caps and when the rubber starts to go bad it can cause a problem as you are describing. Also as said above check the thermostat, a new thermostat will only run you a couple bucks and could be a simple solution.

 

[playa69jcr]

i will prob. put a new in this weekend ill see what happens but what were you saying about the cap i dnt get it?? the fluid isnt shooting out from the cap its shoting out of the over flow tank althought that cap does seem to need replacement

 

[SBstar]

The cap is right above the hose that goes to the overflow...When the cap starts to give up there is something about a loss of pressure and coolant being pushed out of the overflow. I'm not sure exactly how it works but if you search on it you'll find it has caused your problem in the past.

 

[playa69jcr]

alright then thanx for your help

 

[SOADweskey]

I have never bothered to test a thermostat because they just don't cost enough to make it worth while but if you really wanted to you could take out your thermostat and put it in a pot of water on the stove with an accurate thermometer in it and watch what temperature causes the thermostat to open.

And yes a worn filling cap can cause it to go to the overflow as the opening for the hose to the overflow tank is above where the cap seals. When the pressure in the system builds to high because of the fluid expanding the spring in the cap is supposed to give and let water into the overflow tank.