Help! Still have air bubbles!!!

[Jervis Mcstabby]

Ok, I recently bypassed my heater valve so that I'm going straight from the core to the head, refilled and burped my system. I also put some uv dye in to make sure I have no leaks. For whatever reason, I'm still getting bubbles in my system! I've checked the bay with a blacklight multiple times under most conditions (a while after stopping, right after hard driving, highway driving, etc), and I can find no leaks at all. My radiator cap is fine, and my reservoir has maintained its "full" level. I also have a metal head gasket and I recently did a re-torque on the head, but I didn't fully remove the head so I could check how the gasket looked.

So I guess my questions are:
1. Has anyone had such a problem before?

2. Theoretically, is it possible that air from the piston firing could force its way into the water jackets due to an improper seal?

Any ideas are much appreciated!

 

[gaboonviper85]

Has anyone had such a problem before?

close your eyes and just touch the screen...any username you land on has had the problem....these are ma70 supras...just how it is lol

Theoretically, is it possible that air from the piston firing could force its way into the water jackets due to an improper seal?

yes.



but we need more info to really help you.

do you feel any or smell any coolant in your carpet (probably passenger side)....how often do you refill your rad?.....when the car is cold and you take the rad cap off and start the car do bubbles come up?....did you jack the front of the car as high as you possibly can to burp the system?.....do you get the waterfall sound from behind the dash?.....if you have the waterfall sound does it go away when the car is warm?....have you replaced all the coolant hoses considering they are 20 some odd years old?....did you do a combustion gas test on your coolant?....have you dont a compression test?...if so what was the results....

i get the waterfall sound every so often...in cold weather i get it all the damn time but once the car is hot it goes away....i dont go threw coolant at all and oil is fine so ill leave it alone for now....

 

[iwannadie]

close your eyes and just touch the screen...any username you land on has had the problem....these are ma70 supras...just how it is lol



yes.



but we need more info to really help you.

do you feel any or smell any coolant in your carpet (probably passenger side)....how often do you refill your rad?.....when the car is cold and you take the rad cap off and start the car do bubbles come up?....did you jack the front of the car as high as you possibly can to burp the system?.....do you get the waterfall sound from behind the dash?.....if you have the waterfall sound does it go away when the car is warm?....have you replaced all the coolant hoses considering they are 20 some odd years old?....did you do a combustion gas test on your coolant?....have you dont a compression test?...if so what was the results....

i get the waterfall sound every so often...in cold weather i get it all the damn time but once the car is hot it goes away....i dont go threw coolant at all and oil is fine so ill leave it alone for now....

His heater core is bypassed....

 

[Jervis Mcstabby]

do you feel any or smell any coolant in your carpet (probably passenger side)....

Nope, none that I can smell or see

how often do you refill your rad?.....

The radiators always seem fine. As for the reservoir, before I bypassed the heater valve, about every other trip. Hasn't gone down recently though.

when the car is cold and you take the rad cap off and start the car do bubbles come up?....

I haven't checked post-bypass, but one thing I forgot to mention: Pre-bypass, bubbles would come up at a consistent rate (when burping), but once the engine warmed up completely, there would be huge influx of air in the system, causing the most of the fluid to erupt out of the radiator neck till the radiator was about half full. I don't remember this happening last time (post bypass), but I can make sure tomorrow.

did you jack the front of the car as high as you possibly can to burp the system?.....

It was on a incline, but I can always redo it

do you get the waterfall sound from behind the dash?.....

Yep that damn watery/bubbly sound

His heater core is bypassed....

Nope, just the heater valve. I'm going from the core straight to the head.
I probably should have clarified that!

if you have the waterfall sound does it go away when the car is warm?

It seems to stay, maybe less pronounced then

have you replaced all the coolant hoses considering they are 20 some odd years old?....

Yep, every one.

did you do a combustion gas test on your coolant?....

How do you do that one?

have you dont a compression test?...if so what was the results....

I did a compression test few weeks ago, the numbers were:
1.120
2.150
3.150
4.150
5.150
6.160

i get the waterfall sound every so often...in cold weather i get it all the damn time but once the car is hot it goes away....i dont go threw coolant at all and oil is fine so ill leave it alone for now....

 

[Poodles]

cut the jiggle valve off the T-stat... it really does help

outside of that, a BHG is possible, easy to do the test for the exhaust gasses in the coolant...

 

[iwannadie]

Any oil/sludge in the bottom of the coolant catch can?

Heater core not bypassed; its late I misread before ; \

 

[gaboonviper85]

I did a compression test few weeks ago, the numbers were:
1.120

your problem there maybe.

How do you do that one?

go to napa auto parts and ask the dudes there for a coolant combustion gas tester kit...its about $45...it tests for Co2 in the coolant.

I haven't checked post-bypass, but one thing I forgot to mention: Pre-bypass, bubbles would come up at a consistent rate (when burping), but once the engine warmed up completely, there would be huge influx of air in the system, causing the most of the fluid to erupt out of the radiator neck till the radiator was about half full. I don't remember this happening last time (post bypass), but I can make sure tomorrow.

probably because the thermostat opened and let the fluid start to flow....not really supposed to let the engine get hot when you do this cause even if everything is perfect your coolant will still come pouring out.

but if your getting actual bubbles and its spitting and sputtering out then you have BHG.

The radiators always seem fine. As for the reservoir, before I bypassed the heater valve, about every other trip. Hasn't gone down recently though.

this scares me.....every other trip you added water to your overflow res?.....i havent touched mine sense winter lol and i daily drive mine.

more points for BHG.





now im not saying you have bhg.....but i have a feeling you do.....if you feel like spending the money....id go get a leakdown test where they pump compressed air into your cylinders to whatever psi....but do this with the rad cap off and see if any bubbles come out.....do this on a cold motor.

other than that sounds like you got your shit straight....id say BHG myself....start collecting parts.

 

[gaboonviper85]

cut the jiggle valve off the T-stat... it really does help

outside of that, a BHG is possible, easy to do the test for the exhaust gasses in the coolant...

+1

that stupid little giggle thing has gotta go...that helped my waterfall out alot.....i only hear my waterfall for like 2 seconds upon start up if i hear it at all....it doesnt do it very often maybe once a month.....winter is worse.

 

[Jervis Mcstabby]

Cool, I'll check for most of these when I wake up tomorrow!

 

[AJ'S 88NA]

Yep those numbers don't look too good, you said a MHG was it machined for one?

 

[gaboonviper85]

Cool, I'll check for most of these when I wake up tomorrow!

let's us know how it goes.

 

[Jervis Mcstabby]

let's us know how it goes.

Okay I only had time enough for a couple things today, the T-stat and the reservoir. Took some time to cut the jiggle valve, as all the bolt/wire cutters have disappeared from the garage. This too for the hacksaw handle, but I found one of its blades.
As for the reservoir, it was slightly dirty, but no more than usual, cleaned it out and reattached it.

I'm waiting for the housing sealant to set before I fill it up and mess with it some more.

 

[Jervis Mcstabby]

Had a bit of (unrelated) insomnia, so I figured I'd finish the car around 4 this morning. Burped the system, no crazy fluid regurgitating this time (yay for that), and as far as I can tell, all the bubbles have gone! Also took the hacksaw blade and fashioned an easy install fan shroud out of a broken one we had lying about, so now the air is finally blowing back at the engine instead of every where in the bay.

I haven't had time to drive it around much, but so far, no waterfall. ::w00t::

 

[gaboonviper85]

Had a bit of (unrelated) insomnia, so I figured I'd finish the car around 4 this morning. Burped the system, no crazy fluid regurgitating this time (yay for that), and as far as I can tell, all the bubbles have gone! Also took the hacksaw blade and fashioned an easy install fan shroud out of a broken one we had lying about, so now the air is finally blowing back at the engine instead of every where in the bay.

I haven't had time to drive it around much, but so far, no waterfall. ::w00t::

good deal!..... in all supras if you take the rad cap off and start the car after awhile it will start to come pouring out the top as the motor heats up and the thermo opens....but it just pours out not boil....if you get air bubbles that just come up and splash water everywhere then seriously start collecting gaskets and seals for a head gasket job.

 

[CRE]

It's amazing to me... half the people on this forum NEVER have to "burp the system" and the other half do it once a week... What's the deal with that?