What can cause bubbles in coolant tank besides blown HGs???

sizemoremk

Registered User
Just got a new radiator, and noticed a sludgy stuff in the overflow tank.

I did use some of that stop leak stuff, so it could be left over from that.

i cleaned out the overflow tank really clean and now got it all back togetther.

I filled it up with water to get a good flush on it, and once it got it warmed up a little, it started bubbling in the catch can... Seems to increase with RPM...

Can this be anything else, or am I in HG failure denial????

Thanks guys!
 
did you remove the bolt from the neck on the thermostat housing
when filling it helps to get air out but the will be air in places until
coolant is able to move it since it is a closed system the only place to
get out is the overflow tank

have you notice any white smoke
or ccolant in the oil
 
Try the easy stuff first; it's normal on initial start-up after any cooling system work etc. to see air pockets and purging, especially after adding a new rad etc. Did you "burp" it via the stem coming off the thermostat housing before you started it?

Also, check your radiator cap. If it isn't holding the proper pressure the coolant will boil at a much lower temp. I had that happen to mine 2x in the last 5-6 years, and a new cap solved it both times.

Could it be your HG's? Sure, but don't panic until it's time to.
 
I did burp the system from the cap next to the thermstat housing.

I checked the oil earlier, and it looked normal... There was a little white smoke a few minutes ago, but it was a little chilly today... I'm hoping that was the casue...

This all started when I accidentally put a tank of 87 octane in it.... don't know how or why, just a mistake....

I noticed the overflow tank bubling over after a hot afternoon on lots of traffic on a mountain... not good!

So I then replaced the radiator... Hoping it was all that was wrong, it had been leaking a little over a few weeks time....

Just got it in today, and it is now bubbling when it gets warmed up.....

I will try and burp it again, and see where I am...

OH, it didn't bubble up at all until it got warmed up after 5 or more minutes...

Thanks!
 
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Well there are no longer bubbles in the overflow...

I drained and refilled, let it heat up and doesn't seem to be bubbling, there is nothing weird looking in the oil (no matter how high I rev it). I even out in gear and rev'd it a little to put a load on the engine as an old school mechanic suggested, but nothing.

I now however have white smoke, and lots of it, but the car has sat for a bout 2 weeks while the radiator was out, and it is colder today, about 45 degrees according to the weatherchannel.com but I have never noticed this white smoke before. I am hopping that all the rain and humidity have just casued the exhaust to have lots of condensation.

I am about to go and do the 50-50 with prestone, and some napacool additive, and drive it around the block a few....

Wish me luck!!!

Thanks!
 
ive never opened that cap next to the thermostat and ive replace my anti freeze a few times!..would doing that now hlep anything?
 
1fastsupercoupe said:
ive never opened that cap next to the thermostat and ive replace my anti freeze a few times!..would doing that now hlep anything?


If your car isn't running hotter than it should, and you have no other weird symptoms, then it probably won't matter much by now, for you. That's the highest point in the system and if you have an air pocket, opening that tube will "burp" it out. Some people like to do it with the car's front end up on ramps, for an optimum air purge.

It's insurance that air doesn't get trapped, but *most* of the time air purges out of the system normally via the overflow reservior.

It only takes a minute to do though, so it wouldn't hurt if you can crack the nut easy enough. Do not apply excessive torque (on or off) to the nut though as that tube/stem is only a soft metal and will break or twist fairly easy. If you get it off, apply some antiseize compound to the threads of the bolt upon re-install.
resized%20dec%2001%20low%20pro%20side.jpg
 
you just said you have white smoke coming from your exhaust, youve got blown h/g's

thats a tell tale sign :(
 
I got the 50/50 mix and the water wetter in there and drove it abit, and it no longer smoked, I think it was just condensation with the colder weather..

Cuz I drove it all day today (70+ miles) and started to get on it pretty good once it stayed cool all day. It was well below the "N" all day... Even standing on it in the straights a few times...

I kinda secretly hoped that I could do the HGs, that way I have a good excuse to "change out that necessary pully honey" and "have to change out that ruined exhaust sweetie" ;)

I was also thinking of getting the heads done and ported a little, maybe even gettig into one of those comp cams I read about.... since "it was all ruined when those head gaskets went" ;) ;)

But hopefully I can hold off another few months, got a F100 I need to finish off.
 
I have battled the same thing for about 6 months, Car runs Fantastic, oil clean, passes pressure test at 20lbs for 20 min with no pressure lost. Car runs very cool. Not a bit of smoke. :confused:

Have bubbles in overflow and only under boost will the recovery tank almost overflow. Passed sniff test for exhaust in the coolant at a shop ( Not sure it was done well). Bought a good kit at NAPA and it failed 3 tests in row. :(

Changing out top end, which was done about 10K ago. I think it must be a small exhaust to coolant one-way leak under boost. Tired of messing with it, like you said it’s a good time to port and polish the heads, gasket match the intake, etc. :D
Good luck.
(I still hate to tear down such a good running motor. :( )
 
Dude 87 OCTANE !!! NOOO
NOOO

I Ran that twice last year cause of the million dollar gas prices
and it cost me an entire engine rebuild. Cracked a piston and had
both head gaskets leaking just because of two times !!!!
Be careull and get your cylinders compression Tested if you have the chance!
PS what im saying is Blown HeadGaskets. (mine didnt spew that much white
either untill after the rebuild when the cats unclogged themselves
 
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You mentioned doing recent major cooling system work, and you said the bubbles stopped after a period of time. You also mentioned driving it significantly without any excessive temperatures.

Therefore, it seems logical to me that the symptoms you noticed were the result of something else.

The bubbles you noticed were the result of air in your cooling system after maintainance. Even when opening the ventilation cap when filling before starting, you will still have some air left in the coolant. This is why you slightly overfill the resevoir after doing this type of work. They only appeared when warm because that is when your radiator cap opens to bleed pressure from the system.

The smoke you noticed was very likely condensation. My car can sit in humid conditions or rain one day outside and burn off condensation from the exhaust for 10 minutes before it stops. If the smoke you observed was coolant burning, the exhaust fumes would have smelled very sweet (like sugar) and the smoke would have lingered in the air for a long period of time, not dissipate rapidly after leaving the ground like what you probably saw.

Hope that helps..
 
ive run reg in my tank for 3 yrs now...sometimes i do mid and super...but most of the time reg...when i 1st got the car about 6 months later i read the book and it said 92 octane or higher etc.....
 
Thanks guys, I think I'm OK for now...

I think I may have a leak in the heater core though, but if it is, it is very small.

When I turn on the defrost, I can smell antifreeze for a few minutes...
But nly for a few seconds, and get no film or anything on the windshield.

The funny thing is that last summer when I had to replace the AC evaporator, I went ahead and done the heater core. The Autozone replacement had fewer fins and doesn't heat up as well as the old one did,, but I did have it pressure tested before installing it and it checked out OK...

I do have a new water pump and radiator. I am thinking that the bubbles may be from the jeater core leaking...

Any ideas?

I guess I will see if I can get the whoel system pressure tested. Where do I get a kit that can check for exhaust leaks in the coolant? Is that available at Autozone and the like?

It has run perfectly for over 2 days now, in fact today I let it running while I went into one of our buildings for about 15 minutes, and it was still plenty cool when I got back in, WELL below the "N."

SO I don't know if there is a problem or not. The catch can still has the same ammount of coolant in it,a nd I've been checking at every stop for white smoke.

Hope I'm OK!

Thanks alot guys!
 
You can get it tested for exhaust in the coolant at most auto repair shops for about 25 to 30 bucks or go to a NAPA and get a test kit for $45 ( it’s called a Block tester # 700-1006) You can test it about 10 times with what they sell you . It is a chemical test that interacts with the vapor in the coolant. You have to add more test fluid in the bottle for each test. I opted for this because I wanted to perform the test myself. Hope yours comes out negative. Mine comes out positive and the car runs great, just pressurizes the coolant system under boost. Driving me crazy, doing the top end this weekend and next week.
Let us know how it turns out. :D
 
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