Coolant coming out of overflow tank!

[Z'mnypit]

I noticed the supra was running a little warmer then normal the other day so I check it the coolant after it cools off and it was about a half gallon low. I havent had this problem until now. So I fill it up and drive it 30mi or so back home, check it again when I get home and its low again. I park it and havent touched it till yesterday. I toped it off with coolant and started it in the drive way letting it run for about 20min. Come back out side and I have huge water trail running down the concrete. The intercooler was wet right under the overflow tank so im assuking its blowing it out of the overflow tank. The overflow tank was slam full all the way to the top. What could be causing this? Maybe the hose bad letting it blow coolant out but not suck it in?

I know its not a BHG, Ive just replaced the HG with a felpro and ARP bolts about 300mi ago. It not leaking out of the exhaust only the overflow tank. Im going to try to get this fixed soon becuase the car is going up for sale this week sometime.

Thanks!

 

[starscream5000]

Trying burping your coolant system. The car will need to be up to temp, jack it up until the tail pipe is almost touching the ground. Heating on full blast, car running, keep an eye on the coolan level as it burps itself, temp gauge too.

 

[Aspec]

How old is your radiator cap? Test and replace if needed.

P.S. if you can't test it and don't know it's condition replace it!

 

[IJ.]

Not saying it is but how do you know it's NOT a BHG?

What tests have you done to confirm this?

 

[JustAnotherVictim]

Coolant system pressure test.

 

[IJ.]

Napa Combustion gas test

 

[JustAnotherVictim]

Yea if you wanna jump straight to the bhg test.

 

[IJ.]

9 times out of 10 7M cooling issues turn out to be......

 

[Z'mnypit]

Ill run a pressure test and buy a new cap this weekend. Ive got a tester but its at my shop. I dont see how it could have another BHG I just replaced everything. And I can see exactly where its leaking from. It being blown out of the overflow tank.

 

[JustAnotherVictim]

And I can see exactly where its leaking from. It being blown out of the overflow tank.

Which can be caused by a bhg.

 

[MA70Snowman]

I've knwon plenty of fresh HG jobs reblow shortly after, if it was a faulty or shoddy install (not saying yours is) it has a 80% chance of doing so in the first 500 miles. and it definatly sounds like you're getting combustion into the coolant even if just a small amount.

my recomendations:
stay out of boost for the first 500 miles
check all of your coolant hoses, specially that tricky SOB on the back of the head as where that bend is tends to crack pretty easily. and the one that goes to the heater core switch has a pretty shitty clamp from the factory and most people don't think to switch that one out. i've seen that go bad plenty of times. if you have a open in your coolant system it won't maintain the pressure thats needed to keep the boiling point high and what you might be seeing is it boiling at a lower point then it should and flooding your overflow.

 

[DLSupra]

any updates on this? It would suck to have a fresh HG blown to pieces after only 300 miles...

 

[zachm611]

try burping it like others said and maybe get the rad flow tested? i replaced my hg and it still got hot a little but not as bad as before i fixed it, then i got a new oem radiator and my coolant problems were solved. and while i was doing all that i got a new tstat and rad cap.

 

[Z'mnypit]

No updates yet. I just made this thread yesterday. Ill get on it this afternoon.

I dont really have a problem with it running hot, it did that one time because the water level was low and thats it.

 

[PROJECT N00b]

I'm having the same problem, after running my car. After its parked the coolant over flow tans starts spewing coolant, this is the second time it's happend to me. Pointers are very welcome. Thanks

-Justin

 

[IJ.]

Not just a river in Africa......

DE

 

[dbsupra90]

LOL IJ

there is a big difference between bubbling out vs pushing out coolant.

 

[PROJECT N00b]

it was both, the coolant was coming out and was foaming from the over flow and this was after running it on the streets/freeway.

 

[turbo soup]

so how does the radiator cap work? how do you know when it goes bad? i know i have the same problem after i run my supra hard it spews out a little coolant right before i shut it off. but my radiator cap looks really old and crusty, but how does that affect my radiator fluid coming out of the overflow tank? im usually topping off once a month with radiator fluid.

 

[Z'mnypit]

Well, I replaced the cap and drove it for about 15min and came back let it cool off and removed the cap. The coolant was still full but it did blow some out of the over flow tank. Which I kinda expected that when the over flow tank is full all the way to the brim with coolant. Ill try to drain most of it out and go drive it again.