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2G Bubbling in coolant system

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August578

Proven Member
100
23
Jun 15, 2021
Eastvale, California
Hi I did my first head gasket change on my 4g64 98 Eclipse Spyder and when starting and putting coolant in it still has air bubbles and white smoke vapor from exhaust manifold. When first starting there was a lot of foam but went away on its own. The car runs and idles fine at operating temperature perfectly without raising. I also had to change a freeze plug by the cam gear because it had created a hole. This car was sitting for a long time and has a very dirty cooling system. I flushed it many times already but there's still dried coolant in it. Also no white smoke coming from exhaust exit. Any suggestions on what to do next?
 
Don't jump to conclusions just yet. You sure the exhaust manifold isn't just grease and oil burning off? Did bubbles eventually go away? Get some objective data here. Coolant pressure. Check for exhaust in the coolant. Etc. Did you do any machine work or just put a new head on it or what? Give us the WHOLE story.
 
So for the exhaust manifold the smoke went away after some time I think it was just from a new exhaust gasket being installed. The bubbles did not eventually go away after running it for 15 mins. No machine work done to the head because the reason why I swapped the head gasket was mainly because I took of the head to change a freeze plug. The car BEFORE this was sitting for many years and I had started it for the first time but accidentally ran it for a few seconds too long without coolant and think I caused a small head gasket leak.( I did not have much knowledge then and now realized my mistake) Liquid Gasket sealant was able to do the trick and stopped the white smoke from exhaust pipe. Now going back and thinking on this I remember after sealing the head gasket leak there were still air bubbles in the cooling system that would not leave. So I went on for a few test drives and noticed a small hole on the freeze plug leaking coolant and what I thought created the hole was from a dirty or clogged cooling system still. So while the head was off I cleaned out some of the smaller coolant tubes and passage ways from this old dried coolant. BACK now today I remember during those 15mins of running after turning the engine off I can hear the coolant boiling or gurgling from what it sounded like.
I also changed the intake gasket but upon re-installing since the new gasket was paper, on one of the sides where the gasket got really thin, it ripped a little but after doing some research they said just a little rtv gasket sealant on it should be fine so that's exactly what I did.


Also thanks for the link I'll try to do that today hopefully.
 
So....you did a head gasket on a car that had overheated? With no coolant at all? Same head? Were the surfaces prepped at all?
Is it maintaining temp now?
 
I'd assume it overheated a little bit, when I got it to first run the first time ever I ran the engine for maybe a min or so without coolant but noticed some white smoke from the engine and turned off the engine right away. The next day or so noticed white smoke from exhaust. The car had sat outside for over 10 years prior. Yes it is the same head and I'm not sure what you mean by prepping but I did spend over a hour removing all the old gasket from all places where the gaskets needed to be changed such as head, intake and exhaust. I made sure that all the big pieces of what I could get off were off and tried to make it as clean as possible for a mating surface. I didn't check like the actual engine temp but off from gauge on the dash it maintains temperature like normal. But I think the gauge on the dash shows only coolant temps if I am right.
 
OK UPDATE, Good news I let it run for a little longer this time to see if maybe it just has a lot of air in it. So my first run there was foam and bubbles on a cold start and went away around when the thermostat opened. Also my heater did not get warm even at operating temperature. That was when the coolant started to jump and go everywhere. The car had reached operating temperature and so I turned off the engine. I went to go fill it up more because a lot of it spilled out and went to start it again. The second time there was no foam but that might be just because it was warm. Eventually the bubbles stopped arising and there would basically be no bubbles. But as the thermostat was opening bubbles started to come again. I also started to get warm air this time and I'm pretty sure it reached top heat. I kept repeating the process and basically got the same thing. Ima try again tomorrow when the engine has cooled to see if there is still foam forming.

So if there are no bubbles before the thermostat opens does that mean its ok? Its kind of impossible to see if there are air bubbles when the thermostat is open and coolant is jumping everywhere. Also the car runs perfect and no overheating on gauge. :D
 
First off, why did coolant overflow? I'm having a hard time understanding what you've done. Is the cap off while you're running? Overdlow tank overflowing? What exactly is happening.
 
Shot in the dark here, but to your knowledge was there ever any Stop Leak, Head Sealer or any type of "temp fix" additives put in it?

Since there was no machine work done to prep the head/block my money is on the head gasket still. Have you done a compression test since the new head gasket replacement?
 
I had a funnel on top with radiator cap off, and coolant topped off. I'm not sure why but after some time when the car reaches near or at operating temperature it does this thing where the coolant starts to overflow off the rad cap and kind of like surges or gushes everywhere outside of it. Not really sure how to explain it but I'll try getting a video of it if I can. Also before I did a head gasket replacement I did put blue devil gasket sealant. Also I have not done a compression test yet.
 
Make sure you purge the air out of the coolant system by squeezing the lower radiator hose with engine off and rad cap off. Works best after warmed up (thermostat open) but even when cold it's effective.
 
Yeah usually when it surges like that you've either got a air pocket somewhere in the system or you're getting compression into the cooling system. I know you said it's not smoking or steaming but I have a Audi A4 that was doing the same exact thing. No oil/antifreeze mixing, no smoke or steam just bubbling in the overflow bottle and losing coolant ever so slowly. Ultimately it ended up being a cracked head. Did a head swap and it's been all good. But I agree, try burping the system and make sure you got all the air out first before any doom and gloom. :-/
 
Here are some videos of what it looked like after trying to purge some of the air bubbles in the cooling system

Video 1 - This is one of the better starts, before the foam would be at the very top and very foamy like a bubble bath but for some reason only a little bit came out today. Like the amount of foam that is being created is becoming less and less. The foaming only lasts for a few mins and will eventually completely disappear

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Video 2 - No bubbles at all and no foam the coolant stays perfectly still for the next 3 mins. The engine is still warming up and not at operating temp yet. I would say maybe 2/4 from the middle. I thought it had fixed itself and there were no problems anymore.

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Video 3 - Its been sitting at running temp for maybe another 3 mins now but bubbles are starting to appear again.

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Video 4 - The bubbles are becoming more aggressive and the coolant is leaking out a lot more. This is right before it starts to go crazy and everywhere.

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Video 5 - I noticed each time that whenever the radiator fans turn on it does this where it starts to jump everywhere and make a mess. I'm not sure if this is normal and all cars do this but overall the car has been running for maybe 15- 20mins. The engine temp gauge never moved and still remained perfectly at operating temp.

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My next move is definitely going to be a compression test and coolant pressure test but as shown in the videos do you think its a head gasket leak even though I just replaced it? Also since the bubbles are smaller could I just pour gasket sealer and hope it fixes whatever leak it is because it doesn't seem to be a big leak I think? There doesn't seem to be oil mixing in the coolant and no visible signs from the exhaust.

Problems summarized:
1. Foam in coolant but goes away after some time (only appears when first starting cold)
2. Bubbles come then go away completely and acts as if there was no problem for like 5 mins
3. Bubbles come back more aggressively after sitting at operating temperature and eventually start to jump everywhere when radiator fans turn on.
 
You can do a chemical test and verify for combustion gasses in the cooling system. The kits not too expensive and can be found at most part stores
 
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