another cooling system question

S

Synthesis

Experienced Member
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22 January 2006
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1,765
just wanted to see if you guys could help me understand what's going on with my car. let me bring you up to speed first:
- shortly after i got my coolant hoses replaced, i found that there was a small leak in my cooling system, from the left side of the engine compartment, near the firewall.
- i initially thought it might be the cap/tank - replaced them
- continued to have the problem, problem began getting a little worse
- saw some evidence of coolant on the middle big hose in the engine compartment.
- replaced that, and started bleeding the system.

now this is where i'm running into some weird stuff.
1) after filling up the expansion tank to the MAX level, i opened the bleeders.... none of them even had fluid coming out except the rad plug :confused:
2) i ran the car to get it up to temp before i tried again (ofc, after waiting for it to cool)... i left the cap in the mid-lock position (as stated in the manual), and monitored everything.

the rad hoses were getting warm, so i know the thermostat was working, but the fan never came on before the tank got full. i didn't think it was full enough that fluid was going through the overflow tube, but i started to see a little steam coming from my engine bay.... looked under and saw some dripping coolant. could it have been coming out of the overflow tank?

i guess my question is - WTF is going on? when is that coolant supposed to go back into the system? i guess i just need some more info on how the cooling system is supposed to work (as i only have a very basic understanding....) why does/did my cooling system leak????

please help - i'm very confused :frown:
 
just went back to the garage, and found that the bottom of the overflow hose was wet. and realized exactly where it dumps - right on top of the main hose i thought was bad. heh, feel kind of stupid for replacing that hose now :redface:

oh well, live and learn i guess.

but the question still remains: why is my system overflowing?? i've never had any other noticeable problems - the water temp gage stays right where it's supposed to be (just below halfway, right?)

:confused: :confused:
 
UGH i just did another search.
result: possible blown head gasket/warped head???????
FUCK THAT:mad:
i definitely don't need that :frown: :frown: :frown:

is it possible that the place where i got my hoses done didn't bleed the system correctly? how long does air in the system take to f up the head gaskets?

can somebody explain why a blown head gasket causes more overflow?
 
As long as the tanks is filled to the correct level you should not get an over flow. I vote for a bad head gasket. With a bad head gasket compression leaks into the cooling system displacing coolant which comes out the overflow.
 
Briank said:
As long as the tanks is filled to the correct level you should not get an over flow. I vote for a bad head gasket. With a bad head gasket compression leaks into the cooling system displacing coolant which comes out the overflow.
Click to expand...

:frown: my car has 68,000 miles on it, and is stock. (i'm now wondering if it was always that way....)
when i took the trans out, it seemed like nobody had ever messed with it, minus the RS*R exhaust.

this really sucks balls.

how come whenever i checked it while it was running it never filled up that much? was it because i checked it only right after driving, and the airflow kept the coolant cool enough to not expand that much or something?

ugh, either way- i'm screwed. how much am i looking at? :frown:
 
Yeah, been there. To make sure you have a bad headgasket, get your coolant sniffed for exhaust gasses.
The thing went bezerk on mine, gaskets where gone, heads slightly warped, due to bad coolant tank. Had it all repaired, never been the same. New engine should be in by now...
 
DutchBlackNsx said:
Yeah, been there. To make sure you have a bad headgasket, get your coolant sniffed for exhaust gasses.
The thing went bezerk on mine, gaskets where gone, heads slightly warped, due to bad coolant tank. Had it all repaired, never been the same. New engine should be in by now...
Click to expand...

the car runs great, tho..... :frown:
ugh, i'm def going to have to save for this repair - my car fund isn't quite where it was before i bought the type R suspension and started buying parts for the 02 conversion

i wish i knew what it was before i took the trans out!!! the engine was pretty much the only thing left in the rear end of the car lol.

definitely not excited about this.
 
A bad HG wouldn't explain not being able to fill and bleed a cool system. Hopefully air in the system didn't cause the HG to go, and it may be possible that air is what's causing the symptoms you have now, since it would expand a lot when the engine warms up. Do the sniff test--it's an easy DIY. Also bleed the system again until you're sure it's right. Open the bleeders first and then fill it up, closing off each bleeder as it begins to overflow, per 10-6, 10-7 in the FSM. You should also monitor the level of the tank as the car warms up to see if the coolant is indeed filling up the reservoir and overflowing.
 
Daedalus said:
A bad HG wouldn't explain not being able to fill and bleed a cool system. Hopefully air in the system didn't cause the HG to go, and it may be possible that air is what's causing the symptoms you have now, since it would expand a lot when the engine warms up. Do the sniff test--it's an easy DIY. Also bleed the system again until you're sure it's right. Open the bleeders first and then fill it up, closing off each bleeder as it begins to overflow, per 10-6, 10-7 in the FSM. You should also monitor the level of the tank as the car warms up to see if the coolant is indeed filling up the reservoir and overflowing.
Click to expand...

i will definitely get those things checked as well. but i had this problem before i changed the hose. never really saw the coolant level get that high until today when i let it run, but i'm assuming that's what's been happening this whole time.

ugh - i hope it's just air.... if it is, i'm going to have to speak with the dealer that changed my hoses :mad:

any idea why i couldn't get any flow out of the bleeders? i didn't open them while filling, because i didn't drain the whole system. i figured i would just open them after i filled it up.

also, i have never experienced any sort of temp increase in my car. wouldn't that much air cause my temp to go up?
 
If you open any bleeder and nothing comes out, then there is a hugh amount of air in the system. If you are using the gravity method to fill, get the rear of the car as high as you can get it on jack strands, radiator losest, fill, closing bleeders from front to rear, AFTER fluid comes out of each one.

Before we discuss any possible HG situation, let's get it bled right;).

HTH,
LarryB
 
Larry Bastanza said:
If you open any bleeder and nothing comes out, then there is a hugh amount of air in the system. If you are using the gravity method to fill, get the rear of the car as high as you can get it on jack strands, radiator losest, fill, closing bleeders from front to rear, AFTER fluid comes out of each one.

Before we discuss any possible HG situation, let's get it bled right;).

HTH,
LarryB
Click to expand...

+1

usually when its the HG.... depending on how bad it is, the coolant literally blows out the over flow and does not happen at idle unless your HG is completely shot.

bleed the system again
 
alright, i guess i just got a little worried, and expected the worst.

i tilted the coolant tank to try and check behind it..... and it sounded like the tank started emptying some of its fluid into the system. i'm guessing that was an air bubble. also, i cracked the bleeders this time, after opening the expansion cap, and fluid came out this time. the one right on the firewall let a little air out, but that was the only one. (the heater bleeder surprised me!! :tongue: )

i just ran it for about 30 min (except this time i closed the expansion cap all the way), and the level went up a tiny bit after awhile, but stayed pretty much the same. fan came on just fine this time too.

sooo, i am wondering if my problem this whole time (even before i changed anything) was an insufficient bleed. only thing that puzzles me is i never saw the tank actually overflow until this morning when i ran it. i always just noticed some drops of fluid on the floor and, eventually, the level would go down a little. every once in a while, during joy rides, i would stop and check the level, and i never saw it going up like i did today. any explanation for that?

i'm guessing that's what it must be. (i hope that's it.... i'm sick of this problem.) i'll be sure to bleed it thoroughly.

couple of other concerns.....
- did i put my car at big risk of HG problems in the future, if there is no damage now? (should i beat down the dealer that did it... if that's what it turns out to be?)
- any other tricks to make sure all the air is out? i don't want any more coolant dripping down my car!!

thanks guys, for all the help. (i was so glad to not see an overflow this time :smile: )
 
RON98 said:
+1

usually when its the HG.... depending on how bad it is, the coolant literally blows out the over flow and does not happen at idle unless your HG is completely shot.

bleed the system again
Click to expand...

wouldn't the engine overheat or run hot with a blown head gasket?

Does air in the cooling system really causes head gasket problems? Can someone explain please.... Thx...:wink:
 
nis350 said:
wouldn't the engine overheat or run hot with a blown head gasket?

Does air in the cooling system really causes head gasket problems? Can someone explain please.... Thx...:wink:
Click to expand...

Yes the engine will over heat quickly as exhaust gases vaporize the coolant and it shoots out the over flow. here's an illustration. My mr2. has a blown head gasket, I take my customers on test drives around the block in it for fun.

I only do 2 wot runs and I usually fill it up with coolant before I go and by the time I get back, the car is already running low on coolant and is borderline over heating.:biggrin: that car is displacing about 10 quarts of water in 2 wot runs which totals about 2 miles.

The air in the coolant system does not cause the HG issues but rather the air displaces the coolant and its the low coolant that causes overheating and thus the head gasket.

Also in extreme cases of air in cooling system, water pump cavitations can happen where the pump is spinning BUT since there is no coolant at the impellers, thus no vacuum to bring new coolant into circulation , the pump just spins wtih out sending fluid. The car over heats from lack of cooling.

Once the coolant boils over, its a vicious cycle.

The coolant turns into gas, the gas displaces coolant out the over flow tub. When the car starts cooling down, if your coolant tank is full, the coolant gets sucked back.... BUT this only can happen a couple of heat cycles before the coolant in the tank gets all sucked back and now what's happening is once the car starts cooling off... since there is no more coolant in the tank, its sucking up air.... vicious cycle.

on the Mid engine cars, bleeding the system is often tricky since the damn pipes are so long and there are more places for air to get trapped.

you dont have to get EVERY single air bubble out, the heat cycle usually takes care and removes the smaller air bubbles.

I would look at bleeding it first.

Happy motoring

Rob:smile:
 
Thanks for the info Rob....:wink:

I recently replaced both of the drain plugs on the radiator, bottom one first then the top. I just removed and replaced as fast as I could. The coolant came out quite a bit on the bottom one and some from the top.

I didn't bleed the system, but kept my eyes on the temp. It is the same as before, just a bit below the mid point of the gauge (normal range for our cars).

I guess I am ok, right?
 
nis350 said:
Thanks for the info Rob....:wink:

I recently replaced both of the drain plugs on the radiator, bottom one first then the top. I just removed and replaced as fast as I could. The coolant came out quite a bit on the bottom one and some from the top.

I didn't bleed the system, but kept my eyes on the temp. It is the same as before, just a bit below the mid point of the gauge (normal range for our cars).

I guess I am ok, right?
Click to expand...

yep you good.

most of the time the air will work itself out eventurally. just gota keep an eye on the temp gauge the first 100 mile or so if you dont bleed your system.

after that, keep an eye on it as any good driver should.

what i dont get is why they dont make a buzzer for low oil and over heating....:rolleyes:

oh well.

happy motoring
Rob:smile:
 
OK i think i figured it out this time.
i think the hose next to the one i replaced is the one that is leaking.
after bleeding the system out and taking the car out, i still saw a couple drops of coolant on the garage floor.
i saw that it was coming from the same area still, so took a better look. looks like drops of coolant are coming out of the top of one of the hoses (think hose thickness.... that surface.. where where the reinforcements are embedded in the hose). i'm guessing it was just a bad part the whole time..... i'll replace that one and see what happens. i hope that's it..it's got to be!
sucks i will have to go through all that mess again, but it will be worth it.

thanks for all your input, and sorry for tweaking out :redface:
 

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