coolant boiling in reservoir

[2GFWDbeast]

i have a 97 gst with 25xxx on rebuild motor.so i popped my hood and noticed the overflow reservior was full boiling but it only happens when im boosting if i driving around normal it dont fill up my car did over heat but that was do to thermostat the car runs at normal temp. theres no white smoke or coolant mixed with oil my compression is 175 across board. the top radiator hose is super hard like has ton of pressure in it and u can feel it bubbling in the hose could i have a bad radiator cap? or am i pushing coolant at boost im boosting 20psi on a t28. cause it never happened when i had 14b turbo on the car. i dont think the fan turns on i let car run for like 10min at idle and fan never turned on. i bought the car it only had one fan on it someone took the fan that is on the driver side and put it on the passnger side of the radiator so i only have to the fan on the passnger side.

 

[timmy]

If the fans are not turning on then it is over heating. Did you figure out why the fans are not turning on? Is the bottom hose just as warm?

 

[2GFWDbeast]

the gauge dont show that the car is over heating the line is right below half way mark i only have one fan on the car. um i never felt the bottom hose the top hose is really hot tho and lot of pressure in it

 

[xhackerekx]

head gasket

 

[my dreamt dsm]

From my experience.
First check the top hose after a good drive. Should be hard and hot. Bottom should be hot also. If bottom is not hot you can try....
Replacing your cap because the springs might be bad. It is not pushing the rubber to block off the coolant from rushing back to your res.
Second you can check to see if the fans are on when the car is hot. If not you can bypass the thermo switch by plugging in a girl hair pin to turn it on. Drive for a few days. If you are still loosing coolant change your thermostat. If it is not solved. Most likely it's your head gasket. This is just my method because it's from free, cheap and don't involve large amount of money until needed. GL!

edit:
Also when it starts to boil, the longer it does the worst it gets. You will notice white residue under your hood and surround areas by the reservoir!

 

[EagleTSIawd]

This happened to me after I replaced my HG, all I did was retorque the headstuds as I found that they got a bit loose... That solved it for me, won't hurt to recheck the torque on your studs.

 

[just2asian]

Definitely sounds like the headgasket, same exact thing happened to one that we rebuilt a few years back. +1 on HG.

 

[bih55]

well if your fans arent turning on then the engine might be overheating, try turning th ac on and see if the fans kick in

 

[2GFWDbeast]

i only have ONE fan as i discribed in my question someone took the big fan out that was on the passnger side and replaced it with the fan that usually sits on the driver side and i dont think that it tunes on anymore

 

[bih55]

I would just get some fans from the junkyard

 

[2GFWDbeast]

the car is not overheating at all. it did a few days ago but i changed out the thermostat and it didnt over heat anymore

 

[1997_GSX]

Stick your finger in the overflow, If it is really hot it is boiling.

If its not hot but warm your car is pushing coolant which is a bad HG.

 

[nothingfiction]

Stick your finger in the overflow, If it is really hot it is boiling.

If its not hot but warm your car is pushing coolant which is a bad HG.

And... just for clarification... what technique would be used to find out everything is fine?

Not being a c u next tuesday. just wondering. would the coolant be cold if you stick your finger in? i've never tried or even thought about doing this. Never heard of this at all, so i am just wondering.

 

[Demon33]

i have a 97 gst with 25xxx on rebuild motor.so i popped my hood and noticed the overflow reservior was full boiling but it only happens when im boosting if i driving around normal it dont fill up my car did over heat but that was do to thermostat the car runs at normal temp. theres no white smoke or coolant mixed with oil my compression is 175 across board. the top radiator hose is super hard like has ton of pressure in it and u can feel it bubbling in the hose could i have a bad radiator cap? or am i pushing coolant at boost im boosting 20psi on a t28. cause it never happened when i had 14b turbo on the car. i dont think the fan turns on i let car run for like 10min at idle and fan never turned on. i bought the car it only had one fan on it someone took the fan that is on the driver side and put it on the passnger side of the radiator so i only have to the fan on the passnger side.

I had the exact same problem when I switched to an e316g and turned up the boost above 20PSI. When I was on the 14b (17PSI), I never had a problem with the coolant overflow filling up. On the e316g, if I kept the boost below about 20PSI I didn't have the problem, but above 20PSI I pushed coolant past the radiator cap everytime.

I read a lot of similar threads and many suggested the head gasket was bad, but I didn't have any coolant in my oil nor oil in my coolant. I tried 2 different brand new radiator caps (stock pressure 13PSI) and none of them would hold in my coolant under boost. Then I found a 1.3 bar (19PSI) cap in the classifieds and put that on. To this day I have not pushed a single drop of coolant even when I turned up the boost to 27PSI! And my stock head gasket is fine and still going strong.

On Green Performance has 1.1 bar caps for about $15. They say they're good for boost up to about 20PSI. Good luck.

Stick your finger in the overflow, If it is really hot it is boiling.

If its not hot but warm your car is pushing coolant which is a bad HG.

Wouldn't just feeling the side of the overflow bottle be sufficient and safer to test whether the coolant is hot or cold? That's what I would do. I don't think anyone wants to stick their finger in boiling coolant which could very well be above the boiling point of water (212 degrees F).

 

[2GFWDbeast]

ya thanks man i will just get a different cap. if i was drunk blind and retarded i still dont think i would stick my finger in the coolant

 

[timmy]

If you really want to know if it is pushing or boiling, open the overflow when you see it churning (with some sort of sheild between you and the coolant just in case it is boiling. Also, if your fans are not, and have not been working them you would probably see worse damage. Are you 100% sure they don't come on?

 

[GsXdSmKingGsX]

That happened to my buddies GSX also. Turns out to be the headgasket but he continued to drive it anyways (NOT SMART)

 

[2GFWDbeast]

ummm i might turn on idk when i first bought the car the fan would come on at idle but now it dont

 

[2GFWDbeast]

so bought new thermostate radiator cap and fixed fan everything all good now

 

[timmy]

so bought new thermostate radiator cap and fixed fan everything all good now

Do the fans work now?

 

[projekt1]

I too have this boiling issue. Two days ago I let the car idle after a drive around the block (after an rear main seal replacement, oil pan, valve cover and a couple other thigs) and it started pissing out coolant from the overflow, like alot. I opened the thermo hosing and what!! NO THERMO?!?!? I've been using it like that for a while with no issues at all, cooling related that is.

I'm going to take your inputs on first of all getting a thermostat in there then replacing the cap. Again, she has about 2k miles and never and overheating or boiling coolant issue untill last week then this week with the literally pudle of coolant. Haven't ran her again since then either. Could it be the water pump went out (even though it's new too)?

 

[awddsm4g63]

Stick your finger in the overflow, If it is really hot it is boiling.

If its not hot but warm your car is pushing coolant which is a bad HG.

dont stick your finger into boiling coolant.. wow

 

[1997_GSX]

if it is truly pushing coolant it won't be hot at all.

And... just for clarification... what technique would be used to find out everything is fine?

Not being a c u next tuesday. just wondering. would the coolant be cold if you stick your finger in? i've never tried or even thought about doing this. Never heard of this at all, so i am just wondering.

Well you could us a leak down test to ultimately tell if there is something wrong with the hg.

Boiling overflow usually means the water is so hot it is expanding and pushing the cap open forcing the boiling water into the overflow.



If it is pushing, most likely after a few pulls you can touch your over flow bottle and if it is warm and bubbling but not boiling you are most likely leaking combustion chamber pressure into the coolant system causing the cap to open blowing the antifreeze out prematurely.

 

[rstchris]

I have read that the stock HG and bolts are good to 30psi but if he conditions are wrong you can lift the head at low boost levels, I killed my first HG at only 18psi. If you retorque the bolts it might help a little but it's not a fix. Do a leakdown check first to verify. Take a compression tester hose and instead of the gauge put it right to a full air compressor with the radiator full and cap off. Do it to every cylinder and make sure no bubbles come out of the rad. when you air up the cylinders.

 

[2GFWDbeast]

hmmm never heard of doing that but will def try it.