Coolant system question?

[modmonster2008]

Okay so i pinpointed my radiator to be causing the loss of water, and so i replaced it, it HELPED, then i got a new thermostat and rad cap, i topped the coolant off, drove it around no coolant gushing noise, on the way back home, LOTS of coolant gushing noise. Did the same next day topped off then gushing noise after about 20 mins driving. The coolant overflow bottle seems to be playing around the min and max levels and returns to normal the next morning, but i still have to add coolant maybe about 1/4 cup? My question is, where else could it be leaking, coolant did not have any combustion gases, nor was the heater core leaking, it just loses water after driving a long time, engine oil is the normal color and the exhaust doesnt have white smoke unless i first start it then it goes away, where could it be coming from? there are no visible leaks nor any noises of any coolant spraying. anyone could possibly help me? let me know, thanks!

edit: after replacing my radiator i did notice the temp gauge never went up past its normal temp, it would use to occasionally go up then back down, now it doesnt...

 

[NTRA08]

Are you running water or coolant? Coolant has a greater boiling temp than water. What could be happening is the water in your radiator is boiling and creating pressure, too much for the radiator cap to handle, and releasing it into the overflow tank until the high pressure from boiling over is released. OR. You could have a faulty t-stat. If your t-stat isn't opening like it should you will build too much pressure and it will be released into the overflow tank. And then it will open. A while back I had a similar problem. My car kept spilling coolant out the overflow tank and it would overheat. Everyone was saying I had a BHG. Well jdub stepped in and helped me out. He told me to cut the jiggle valve off, as it being removed it would relieve the pressure and open the t-stat. It worked I haven't had a cooling problem since. So I would try that. And see what happens. If you are running straight water replace it with coolant.


BTW thank you very much jdub

 

[A. Jay]

A little off track, but are you using the stock temp gauge? If so, I want to let you know that it's desgned to not move for a big range (see this post).


- from my Archos 5 IT

 

[modmonster2008]

As for NTRA08's post, I am running coolant in the system, but i believe since the leak was repaired i have been using more water in the mixture than coolant (3 h20 to 1 coolant) could that be causing the issue? I have a new OEM thermostat already and cut the jiggle valve off. It just seems to be losing a bit of water every day without any visible leaks, the water from the overflow reservoir returns back to the radiator as the tank level gets lower than when it was running i checked the next morning, its just when i open the radiator id have to keep adding a little more water everyday and its just difficult to find the leak when i cant smell coolant, cant see any leaks, and hear any hissing.

A. Jay: Yes i am using the stock temperature gauge, and if there is an alternative, what could i use? thanks

 

[SRZMK3]

i hope this isnt the problem for you... but check behind the engine for leaks that metal heater hose that wraps around the engine corrodes,leaks, and you can usually not see it but hear it...

 

[NTRA08]

SRZMK3 your right. Also the 90 degree 5/8 hose on the pass side that connects to the front main from the pipe on the side of the block. I had mine leaking there and never saw it until I got shot in the face when is burst. Also there are two hoses on your TB and two on your IAC and one on the bottom of your intake. Check those too. Running that much water to coolant might be your problem. Or it might not. At least you got your t-stat out of the way. Did you replace your rad cap?

---------- Post added at 02:30 PM ---------- Previous post was at 02:28 PM ----------

You could also drain your system a little and put a dye in your radiator. Fire up the car at night and check for leaks with a UV black light

 

[modmonster2008]

alright i will check the 90 degree hose on the back of the engine bay as well as the metal hose that wraps around the engine block its just weird how i dont see smell or hear anything and i dont see moisture in the car so no way its the heater core. Ive ran full water on other cars before they never had a coolant gurgling noise and yes radiator cap was replaced the same time i did the thermostat and radiator i just dont know where else it could be leaking..

 

[NTRA08]

If all else fails use the dye and a uv black light

 

[modmonster2008]

updates, no visible leak has been found but i did notice the water level always dropped after an hour or so, im hoping its not the heater core, not head gasket as the exhaust does not smell like coolant, nor did the cooling system have exhaust gases, i did notice the hose under the dizzy was suppose to be a 90 degree bend that was kinked to sh*t like it was a straight hose forced on there, ill be replacing that tomorrow, re-torquing my head gasket, and if all else fails, then idk what else to do...

 

[modmonster2008]

replaced all heater hoses with new ones, 90 degree bend hoses are new as well, rad hoses are new and clamps are new as well, head gasket is torqued to 85ft lbs, heater valve bypassed, rad is new, cap and thermostat is new, no apparent leaks anywhere, no fogging up windshield inside, where could the water possibly be going still??

 

[NTRA08]

you got me.

 

[hvyman]

Do a cooling system pressure test and a compression test.

 

[modmonster2008]

compression readings were high (didnt take notes of the PSI) but they were high all i know lol, coolant system maintained 11psi pressure on the pressure tester, coolant noise seems to have decreased like theres only small bubbles in there now, will check level tomorrow and top off if needed, im guessing i need a OEM toyota radiator cap as i heard slight hissing that goes away when i press down on the cap..

 

[modmonster2008]

updates, would you guys think its a bad radiator cap? the coolant in the overflow bottle goes to the hot level but when the engine gets cold it only returns a little bit of the fluid back into the radiator, i also noticed, i installed a tee-connector by the heater valve where i usually would check the water level, and when i would squeeze the small overflow hose (with radiator cap installed) the fluid level on the tee would change, so would that indicate a bad rad cap?

 

[metaphysico]

Bad radiator caps cause all sorts of problems and mis diagnostics. What can happen especially with running high water to coolant ratios (as I always do), is the water will boil faster. The cap is supposed to hold pressure in the system which will keep the water from boiling.

If the cap does not have sufficient pressure to keep the water from boiling it will escape as steam from the radiator into the reservoir, and can escape from there as steam.

Also another thing that will cause a problem is if there is a hole in the hose going from the radiator nipple to the reservoir or if it has a bad connection on either side, this will cause the steam to escape from before going into the reservoir and becoming water again. Then after a few engine cycles it will take some of the water back in the reservoir and appear that you are loosing coolant/water.

Of course all these problems are amplified by having mostly water as the coolant is not there to help the water keep from boiling. Also it could be that the cap is leaking past is main seal and loosing steam that way then when the system starts cooling off and the radiator will seal under the vacuum of cooling and will pull coolant from the reservoir.

But when getting a cap go somewhere and when they pull it have them check to make sure it holds pressure. You would be surprised at how many caps I get that wont hold more than 5psi pressure max.

Just for the hell of it here is a rundown of what happens in the motor in a heating and cooling cycle minus the thermostat and waterpump.
Radiator and engine are full of coolant. Engine runs heats up coolant. Coolant expands and pushes the secondary seal in the cap open to let the expanded pressure go into the reservoir, while keeping a needed amount on the system to keep pressure up and keep coolant from boiling. Then when you shut the car off the coolant will start to shrink back down. This creates a vacuum in the radiator and engine, which pulls the backflow valve on the cap open(the metal part on the bottom of the cap) which allows the cap to suck coolant back in from the reservoir. Btw the primary seal on the cap is what keeps the coolant and pressure in the upper neck of the radiator. When pressures build up enough to push the secondary seal. The secondary seal is the part that sticks down and has the spring that pushes on it.

Sorry if that was all too basic but its suprising how many people dont know what happens in a cooling system.

 

[modmonster2008]

so basically i think i have a bad cap then? yesterday after a long road trip i shut the car off and opened the hood, there was a slight hissing noise coming from the radiator cap area, and when i pressed down on the cap (yes it was hot) the hissing stopped and reappeared after i let go...

 

[metaphysico]

Yep sounds like a bad cap, when u get a new one have it tested before u leave.

 

[modmonster2008]

got a new rad cap ill see whats up with it after a long drive tomorrow

 

[modmonster2008]

Updates:

Got a new OEM toyota cap, and after about 60-70 miles worth of driving the car acts funny, i shut it off at a gas station and i could hear the coolant pressure pushing out of the radiator into the overflow and its somewhat bubbly not oil colored though, i also did notice i keep having to add water every morning though there are no leaks on the car, is this a beginning sign of BHG? and would a simple block seal head gasket sealant fix this? im assuming that the leak is only small

 

[hvyman]

Head gasket fix is a joke.

Sounds like the hg is going. Run a block test.