coolant bubbling?

[SRspoolin]

i dont think its overheating but what would cause this? any ideas on how to fix it?


Modified by SRspoolin at 6:32 AM 8/19/2007

[T-rev]

where is it bubbling? into the plastic overflow container? If thats the case it means there's air in the system

When is it bubbling? white your running or when its off?

If you just popped the rad cap off and theres a couple bubbles its probably just air working its way out of the system.

BUT since I am paranoid, check your coolant for oil, and your oil for coolant. Worst case scenero is a leaking head gasket

[SRspoolin]

its bubbling into the overflow tank when i shut teh car off. i sat there for 30 mins gettin the air bubbles out, i dont know how air is still in the system.. i did a flush a few weeks ago and no oil in the coolant and i also did an oil change at the same time and it was coolant free also.

[T-rev]

ok well sounds like the HG is fine, good to get that out of the way first.

I had the exact same problem on an old camaro, the rad cap spring was shot. I got a new one and it fixed the prob. Is your cap new or the stock 17yr old one? Stock ones should be pretty cheap <$10. Also I think Nismo makes a 1.3 bar or something.

That rubber hose that leads to your overflow could have cracks in it, so the rad would draw in air instead of coolant, and then blow bubbles when you shut her down.

[SRspoolin]

yeah i thought it was the stock radiator cap since its old as ****, but i picked up a z32 tt radiator cap two days ago and its still doin it.. ill check that hose but im pretty sure it doesnt have any cracks.

[doridori23]

Do you have access to a coolant pressure gauge? That and a dye test are the only two ways to rule out a head gasket or head/block leak.

[SRspoolin]

Do you have access to a coolant pressure gauge? That and a dye test are the only two ways to rule out a head gasket or head/block leak.

im not sure, could i pick one up at autozone or something?

is there any other things i can look at to see whats causing this? its ****in annoying and pissin me off

a few days ago after driving for a while, i was idling and if i tapped the gas pedal real quick it would pause then rev but i tried it the next day after warming it up and it didnt do it.. what could cause that? does it have something to do with the coolant bubbling and maybe getting pretty hot?

[doridori23]

Throttle hesitation could be a number or things but as it went away we'll have to wait to look for the gremlin.

You can pick up one at autozone but rent one first. Call ahead and make sure they have one to rent. Drive the Smodel there and let it cool off. Then remove the rad cap, add coolant if necessary, and install the pressure tester. First try to pump up the system to 13psi. After you get it to 13psi let it sit for about 5 mins then come back and look at it. If it has only dropped 1-2 psi and no coolant on the pavement then its ok due to the fact of the coolant will shrink as it cools reducing the pressure that you created. Start the car WITH the pressure tester still attached. just idle the car and watch the gauge. If it starts to go higher than 17 VERY CAREFULLY (read with a glove and a rag) crack the pressure tester to allow the over pressurization to go into the overflow tank. Once the gauge gets down to about 10 tighten it back down. If you have to do this a dozen times over the course of 3-5 minutes there is a good chance that you have a leaking head-gasket. Ask the Autozone employee if they sell dye to detect a head gasket leak into the coolant system. It checks for the existence of emission gasses and suspended solids in the coolant system and 95% of them are simple. Take a sample of coolant from the rad and add an amount of tester that the bottle sais. It it turns purple/black then you have 2 reasons to do your head-gasket and head studs.

[SRspoolin]

i need to go get that asap.

i did some work on it today.. its better but still does a few bubbles

[doridori23]

What did you do and how large was the improvement?

[SRspoolin]

i put on the fan shroud and took off one of the hoses, so i added come coolant and got the air bubbles out and it help a ton but theres still bubbles comin out of the over flow tank.. i need to do that test you explained above.

i think that throttle hesitation went away.. i borrowed my friends heat gun, you point it at something and it tells you the heat.. how accurate are those?

[SRspoolin]

ok so heres what its doin.. i went to check on the coolant level and it was low. i filled it up and did the whole bleeding ****. so i turned the car off and the coolant hella started to over flow so im thinkin thats what its doin so it starts to over flow and has know where to go then it bubbles into the over flow tank and fills it up then after its done with all that the over flow tank is full and then a low level in the radiator(thats why it was low when i checked on it today).. so what would cause this to over flow when i shut the car off? is this normal or what?

[SRspoolin]

anyone? /\ /\ /\ /\ /\

[doridori23]

No it is not normal. With the temp-gun from your friend when the car has warmed up point it at the rad, block output neck (top) and clock input neck. Then do the pressure test and tell us what you get.

[SRspoolin]

i got the coolant pressure gauge but i cant figure out how to use it.. i dont think it came with the right size for the filler neck

[SRspoolin]

another thing i noticed.. i have a z32 tt radiator cap and when the cap is on the radiator i can move it up and down so its not gettin a good seal.

[SRspoolin]

the arrow that points to each side, i can move that up and down..

[Emperor_Tha]

pressurize the cap, or borrow or get a new radiator cap for your car.

[SRspoolin]

i bought the new cap maybe a month ago. i did test the cap and it was fine. i need to do that coolant pressure thing on the radiator but it doesnt fit on the filler neck so im stuck on what to do...

[silvia tech]

Have you checked your radiator hoses. are they paper then and expanding then releasing pressure when you turn the car off. Second go get a New Cap perhaps consider getting one for a 240sx, dont get the one with the freakin red tab they suck. Also when you bleed the system how are you doing it. I traditionally jack up the front of the car by the tow hook or core support if need be. Turn the car on and turn the heater on full blast with the radiator cap off. The air will naturally rise to the highpoint, the open radiator neck.

[SRspoolin]

red tab? it doesnt have that. i read a thread that has parts that work for the sr and thats one of them. and the way i bleed the system is the same way, ive done it plenty of times.

im not sure on what you mean for the hoses..

[Jadesr20det]

Any developments?? I was having a similar issue and had to bleed the damn system for 30 min with heater on full blast and steady revving at 1500 to get the bubbles out of my radiator. My issue was the car would drive perfect heat up a lil at long lights and drive thrus (damn you Popeye's) then when I got moving or turned the car off briefly it would be fine.

[SRspoolin]

i still havnt fixed this problem yet.. i need to get the right adapter for the filler neck but i dont know where. it should have came with the right size but it didnt.. weak.

wheres the drain plug on the block to empty the coolant?
Modified by SRspoolin at 4:48 AM 11/27/2007

[Jadesr20det]

I'm planning on getting the little particles out by just running massive amounts of water through the rad system prolly with hose on high stream to losen all the crap up. As far as the bleeder screw I didn't even mickey mouse with it and used the rad bleeder on the bottom of my koyo and switched out my thermo at the same time and that took care of the coolant in the block. GL

Keep us posted

[SRspoolin]

anyone?

[SRspoolin]

i did a compression test and the numbers were all good, so its holdin' pressure.

the guy before that owned my car had different spark plugs, 3 champ and 1 ngk. that probably ****ed my **** up, whata ****in idiot.

[drifter_for_life06]

screw it, if your having cooling problems and cant figure it out....might as well save and drop some bank on a new thermo/rad/and possibly a water pump...if the problem is still there after you do ALL that AAANNNDDDD bleed it the CORRECT way...you did something wrong