cooling system prob. help pls!

[drag]

hello, I have a nissan 240 sx 89 sohc. I have problem with my car. I always have like pressure in my radiator. like after i drive my car, i squeez my radiator hose and its hard, if i drive it for long, maybe it might burst like last time. i already bleed it, but keeps on coming back. like one time after i bleed it, i drove it n it was fine, i check the hose n it was soft. then the next day i drove my car again and it came back, the pressure, like the hose wanna burst. so i just left it alone till the next day i open the radiator cap and coolant splash all over my face. i dont know what to do anymore, l been trying my best to fix this crap 4 almost a month now. I dont know if i'm bleeding it right or what. the way i bleed it is, i lift the front end of the car n i open the bleeder screw n i put coolant n squeez the hose n run the engine and i do it over n over again. but when i keep the engine running, like thers a nonstop bubbles coming out from the bleeder. i dont know what to do anymore . can anybody help me with my problem pls. thanks

[KaDrifter]

The cooling system is a pressurized system. So the hose are supposed to be hard after driving. If they are soft then it is not building pressure. How new is your thermostat? Water Pump? Rad Cap?

[drag]

I took out my thermostat. because here in this island is very hot, we are right below the equator, thats what the shop here sed. n my water pump is kinda old, only little rust but its in food shape, n my cap is old. thanks for replying man.

[KaDrifter]

I would suggest the raplacing the water pump, and the cap. I really wouldn't advise taking out the thermostat bucause Nissan uses coolant sensors to adjust the fuel mix. Would suggest to get a low temp.

[navysnail]

yeah, leave the thermo in there

how old are your hoses, and are they squishy when its cool

oh, and dont run the eng ine with the bleeder open, thats prob. what your doing wrong. what you do is open the screw, then pour coolant into the radiator untill it comes out a little, then put the screw back in, cap it off, and your done

[Nismo_Freak]

yeah, leave the thermo in there

how old are your hoses, and are they squishy when its cool

oh, and dont run the eng ine with the bleeder open, thats prob. what your doing wrong. what you do is open the screw, then pour coolant into the radiator untill it comes out a little, then put the screw back in, cap it off, and your done

No the thermostat will be closed and not allow coolant into the bleeder area. You run the engine with the bleeder open until the coolant starts to come out of the bleeder, then you tighten it back down. I also like to run the engine with no radiator cap for a minute or two to allow any bubbles in the radiator and/or system to evap out.

Now onto your question. It sounds like you have a blockage somewhere. If the thermostat is not sticking (because it's not there) then you might have a mineral deposit blockage. You should flush your coolant system very well, I suggest twice if you get alot of debris in the old coolant, with a low concentration coolant : water mix (35:65).

The coolant MUST be ethylene glycol to run a 35:65 mixture. Propylene glycol requires a different ratio to sufficiently raise the boiling temp of the mixture.

Now, install the thermostat back into the engine and run the 35:65 mixture which I know works in a very hot environment (I live in Texas - 100+ ambients). The more water you can run in the mixture without it boiling the better the cooling properties.

Now some questions:

- Does your car overheat? Did it overheat before?- Does it feel sluggish? - Does it burn coolant at all?

[navysnail]

do you really run it with the plug out, i was just wondering since the FSM says to replace it before you start the engine, but ill have to give it a try next time i change mine

[s13sr20chris]

i have never run it with the bleeder open but i will have to try it sometime.

[drag]

No the thermostat will be closed and not allow coolant into the bleeder area. You run the engine with the bleeder open until the coolant starts to come out of the bleeder, then you tighten it back down. I also like to run the engine with no radiator cap for a minute or two to allow any bubbles in the radiator and/or system to evap out.

Now onto your question. It sounds like you have a blockage somewhere. If the thermostat is not sticking (because it's not there) then you might have a mineral deposit blockage. You should flush your coolant system very well, I suggest twice if you get alot of debris in the old coolant, with a low concentration coolant : water mix (35:65).

The coolant MUST be ethylene glycol to run a 35:65 mixture. Propylene glycol requires a different ratio to sufficiently raise the boiling temp of the mixture.

Now, install the thermostat back into the engine and run the 35:65 mixture which I know works in a very hot environment (I live in Texas - 100+ ambients). The more water you can run in the mixture without it boiling the better the cooling properties.

Now some questions:

- Does your car overheat? Did it overheat before?- Does it feel sluggish? - Does it burn coolant at all?

no my car dont overheat, the gauge just stay on the forth line. but before it over heat koz when the hose burst. and it dosnt feel sluggish. n no it dosnt burn coolant.

thanks man

[drag]

hey guys, thanks for all your help. my problem is done. I just keep trying diffrent caps n keep on test running, i found the right one, n now pressure is releasing to the coolant resevior. u guys been a big help. thanks you all. maybe later i have more questions. PEACE OUT! Neo...........