Altilude

ok, for the most part I like to think i keep my car well maintained, but i noticed an issue today that's got me on edge.

it was a hotter than usual day where i live, and after shutting down I heard - a boiling sound, so I cracked the hood, and the boiling sound could be isolated to the overflow reservoir, which was holding within the limits, but boiling like crazy. I couldn't hear any boiling from the radiator, I felt both the upper and lower rad hoses, neither were kinked or nothing, and both felt quite hot (atleast the lower indicates that the thermostat was doing it's thing - and the thermostat was changed last year)... last week, i topped up rad fluid and even bleed it at the correct place on the thermostat housing, so i know it's not due to a depletion... I also idle'd the car for a while (because it had to come up from cold) to bleed it, and checked then that the fans both operate as required, when reaching sensor temp. the stupid thing is - my ECT, is only showing middle of the road temps... so why... WHY? do i got coolant boiling in my reservoir? the only thing i can think of is a sheared waterpump that ain't doing sweet f'all, in combination with a faulty ECT sensor that shows me a happy medium, when it's unhappy. it's a jdm engine so i only have the one fan switch A. the other thing is my coolant isn't a top name brand but I didn't think that would make a huge differenence... the worst thing is, i have to make it to ATLEAST the weekend, before i can take a look at the waterpump, as this car is my daily. );

any advice appreciated.

Jagan'92

you topped up the fluid, but have you drained and flushed it? is the color of the fluid good or is it rusty looking?

Altilude

it's still looking good, from what i can tell, a nice green. rad was totally flushed about 17 000 miles ago... hmm is that interval too long?

mrOswaldIII

Did you add to much coolant and not enough water? I think you need around 50/50. Is there presure in the coolant hoses or do they feel flat? I guess if you have to, at least drive around with the heat on as it will help somewhat.

Lewdin' Incognito

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrOswaldIII &raquo;</TD></TR><TR><TD CLASS="quote">Did you add to much coolant and not enough water? I think you need around 50/50.</TD></TR></TABLE>

Too heavy on the water would do what you're thinking, antifreeze raises the boiling point of the water; but since he said it was nice and green then I would say that's not the issue here.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Altilude &raquo;</TD></TR><TR><TD CLASS="quote">last week, i topped up rad fluid and even bleed it at the correct place on the thermostat housing</TD></TR></TABLE>

Have you gone back and made sure you tightened everything back up? Definitely sounds like you are losing coolant somewhere, I would start with whatever was last touched. I think it's highly unlikely that your waterpump just suddenly somehow got sheared.

Altilude

thanks for the replies guys... yea everything is tight, I was thinking back to when i bleed the system the other day, and i don't think that i had the heater on/cranked - perhaps i still have air in the system. i think there is definetley a depletion of coolant, because today when i arrived at work, i immediatley popped the hood to see if there was any boiling/weirdness - and the reservoir was just about empty - now i know the thing fluctuates, but i had it right in the range about a week ago. - i'm not puffing white or anything, so i don't believe it's a headgasket(?) but a blown head gasket could pressurize the cooling system could it not?.. the hoses don't feel too flat but feel rather hot (maybe too much so?) on shutdown. i won't have time/equip until the weekend to take a look at the oil cooler hoses and such for possible leakage.. just sucks driving like this, but i got some extra coolant with me now, and i drive around in this crazy hot weather with the heat cranked (it sucks). if anyone else thinks of something please put in your input.

Altilude

ok so it's not boiling ... as in technically boiling, as i had first thought. today, same thing - after a long drive, i shut down and hear the boiling sound from the overflow reservoir... so i undo the cap on it, and the hose to the rad is just venting into the coolant hardcore (making the bubbling boiling noise),.... so i'm thinking i'm over-pressurizing my coolant system somehow? does this all spell head gasket? or what would cause such a phenomenom... atleast i'm not overheating... but i want to get to the bottom of this.

Altilude

any chance it's a rad cap? and not a head gasket... any idea's anyone?

symptoms
rad - pressurizing overflow reservoir on shutdown causing bubbling (not boiling!)...
cooling efficiency - still good (car never overheats)
fans work,
systems bled,
maybe a few minor minor leaks (hopefully i can tend to those tomorrow)
both hoses exhibit heat, meaning thermostat working.

reasons i don't want to suspect hg
no oil in coolant
no milky bubbles
no white smoke out exhaust
good compression numbers (does that count?)
it would be a real pain in the ****.

come on coolant guru's

onefastrx7turbo

as stated above, make sure you have a good mix of coolant and water. 100% antifreeze will create the problems you describe, but so could air in the system. do you have heat in the car? when the car is cold, open the rad cap. add coolant as necessary. start the car and turn on the heat full blast. keep the rad cap off and see what the coolant level does. Also, if you have to add coolant, open the bleeder on the engine side of the hose. fill until coolant comes out of it, then close it and continue adding coolant. also, how is the Tstat?

hondamanmark

well i will tell you one thing....my factory radiator caused me to have to spend about $3000+ cause the first time radiator failer caused me to have to spend $1600+ to get valves and pistons fixed......which i got that fixed but it did enough damage that that rebuild didnt last all that long.....i ended up getting a CSF race radiator (same as KOYO) and it was DEF. worth it

Altilude

just for closure - i thought i would update, in case anyone is searching for a similar problem in the future.

I decided to go the cheap route first (typical guy eh?) so i picked up a brand spankin new (non oem mind you) rad cap. the bubbling, has gone away, disappearing coolant (probably caused by the bubbling) has also gone away... so it appears the problem is solved. cheap wins (this time..).