REW138

Hi all,
Please break it to me gently...

Is this the dreaded champagne effect of a bad coolant seal?

Background on the motor:
13B naturally aspirated (stock).
Rebuilt (approx.) <20,000 km ago (but some years now).
Sat idle for 6 years in garage.
Recently returned to the road and runs beautifully.

The last drive of this car, the coolant overflow... Overflowed, the ADD COOLANT light and buzzer came on, however the temp was all fine (1/4 - 1/2 gauge).

I took it off the road and replaced bottom hose, top hose, BACV to Throttle hose, cleaned the BACV tubing, cleaned out the reservoir, replaced thermostat, radiator cap and new gasket/sealant, replaced the coolant temp sensor, and ensured that the block, radiator, fan removed and cleaned, water pump etc were all flushed and in good working order.
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I used my Lisle funnel to bleed the coolant and as far as I can tell, it should be good to go and better than ever (with fresh longer life coolant added too).

I have been on a couple of shorter drives since and run it weekly to just keep everything moving over.

I put the Lisle funnel back on today, because I just had an inkling that something must have been bad for what had occurred, and everything I took off and replaced seemed to test fine. I let it heat up and topped up the funnel to bleed some more.

I noticed (amongst some debris which I believe to be black gasket sealant) bubbles every so often.

I recall reading on here about "champagne bubbles" and how that's not a good thing - in this case.

Does this video show that?
Please put me out of my misery, this is so heartbreaking if true - the amount of money I've put in to keep this thing stock and tidy.... :-(
​​​​​​Is it ok to still drive it?

j9fd3s

iTrader: (3)

that looks good enough to me.

the coolant overflow setup has the engine pushing out coolant when it gets warm, but to pull it back it needs to be able to have a low pressure. if there are leaks in the cooling system, it won't be able to have the low pressure and the coolant overflow, overflows....

also i've seen the cap and the surface it seals on have debris, and then it acts like a blown water seal, but isn't.

REW138

So the 'not low pressure ' is possibly due to exhaust gases in the cooling system? Or just that an air leak can appear somewhere in the cooling system?

I put the debris between my teeth (because they're too small to be able to feel between my fingers) and it definitely feels like RTV gasket sealant.

Best to drop it in somewhere to get the system leak tested, or is that unnecessary given the symptoms?

rlynchster

In my circumstance, the exhaust channel allowed pressurized gas to enter the cooling circuit and then it pushed the cooling water into the overfill reservoir.. . . .The reservoir filled up all the way to the top when the car was hot and the low level alarm would go off. (triggered by the sensor on top of the radiator)

I took about 2k miles before a simple 50 mile run would fill up the overfill reservoir and set the alarm off right after a known good fill of the cooling system.. ..So for me this was a failure mode that took some time to finally cause me to stop driving the car. .. . . ..At no time did the temp gauge give me any clues as to what was going on. Towards the end, it was the water puddle underneath the car coming from the reservoir vent tube that told me something was up.. .. .Eventually I couldn't drive 20 miles before the low level alarm would go off and the reservoir would be full from all the water being pushed into it.

All this being said, I've also had a situation where the sensor on the radiator went bad and caused false low level alarms.

REW138

Seems like my symptoms would suggest something more sinister than just the radiator sensor, yes?

I am feeling the doom here. Purely heartbroken.

I know I can't drive it, and I gather I can't get out of this simply without $$$.

Is there anything else that might help or get me out of hot water here? (Pun intended).

Thanks for your reply, your story is also one of pain, I can see.

Edit: I don't know why, but I put "6" years off the road, it was more like 8 with a rebuilt motor - not good value for money at all - 7+ grand AUD cost, too (I gather it's a lot more these days). Also just went back to paperwork on the rebuild and it was almost (just 50 or so KM shy of) 20,000km on it.... Sad.
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diabolical1

iTrader: (3)

have you tried draining it, then pressurizing the system and seeing if it holds?

REW138

I don't have a pressure test kit, but I could see if a local mechanic can do that for me. Best I can hope for is a poor hose seal or something minor causing the air leak, I guess.

Coolant has been filled completely and air bled, so I guess that's good for now.

Is that what you mean by drain and pressurise?
Usually you pressurise with coolant in, right?

diabolical1

iTrader: (3)

i suppose it doesn't matter if the system is full or empty, but i just figured it would be simpler if it's empty. my point was really just to see if the system will hold a known pressure over time ... something empirical.

REW138

Ah, righto.
I thought maybe with fluid in, I would be inspecting leaks. I get what you mean now and yeah, I guess that's a sure fire way of knowing for sure. With fluid in, at least I can identify any leaks from hoses etc.

Where would the "coolant seal" in question reside? Is it a smaller o-ring or a larger rubber seal around the housing?

diabolical1

iTrader: (3)

we're talking about either a broken coolant seal (likely inner, around the housing) or maybe an eroded seal land (the housing itself). if it proves to be leaking, then you won't know which until you pull the engine apart.

REW138

Aw that sucks.
I am just going to have to save and get it done.
Already spoken to a local Rotary Tech here in South Australia, so hoping I can get this done within 12 months, but saving ain't easy these days.

Thanks all. I really appreciate the response and discussion.

I'll report back when it's been looked into whilst apart.

Good opportunity to consider a very mild port, too, I guess.

gracer7-rx7

iTrader: (16)

Yeah, that's less bubbly then stale, flat beer - or milk. Definitely don't see evidence of a coolant seal failure in that bubble test.

Recommend you do a coolant system pressure test. That will help identify any leaks. YouTube has some good videos about how to perform one.

REW138

Ooh, I like that take (I don't like flat beer though).

What is evidence then of a coolant leak? More constant and aggressive bubbling or the colour/look of the fluid?

I will get the system pressure tested, so what would be the possible outcome of that? Areas that I should look?

If I also added that there seemed to be 'condensation' on the underneath of the oil cap, would that change your initial opinion at all?

Thanks for replying.

REW138

PS. Is that a photo in your avatar of yourself at Laguna Seca?

Raced around there in Gran Turismo, but being from Adelaide, Australia, it's somewhat of a legendary track I have always wanted to go to.

diabolical1

iTrader: (3)

there is no standard behavior that you're going to find. as i said before, the pressure test is probably your best bet for data that doesn't involve pulling the engine apart and eyeballing a failure.

it happened to me twice with my '84.

the first time was pretty dramatic. i left work one night and heard a noise (similar to a goose honking) coming from the engine bay. i pulled over and started following the sound, trying to pinpoint it with my ear. the next thing i knew, the overflow container lid pops off and hot coolant sprays all over my face and chest. at the time i didn't know what it was, but in the days following that night, when i restarted it with radiator cap off, it bubbled over pretty spectacularly.

the second time it happened (years later with a different engine), i kept losing coolant with no leaks. car would start fine when cold, but random trouble with hot starts. never knew what was going on until i went to change an exhaust manifold gasket. i happened to turn the engine by hand, and coolant poured out the chambers - a lot of it. car never overheated and no obvious signs of excess pressure in the system. it ran like that for years. my guess if if i had the knowledge to pressure check it, i may have found out way before i actually did.

i've shared that to say, you may be right, but you also may be wrong. don't condemn it until you check.

REW138

Holy moly! You were lucky if you got out of that without burns.

There's a discount sale on at my local auto parts store, so might just buy a pressure test kit - sub $AU100 - which is probably what I would pay for a radiator tech/mechanic to look over and diagnose.

Saying that though, the coolant test kits for hydrocarbons, are quite pricey, so might take it in for that.

Thank you for your examples and reply.

REW138

​​​​​​Decided to chase some coolant lines.

Got real thorough with the inspection mirror and lamp.

Found this underneath the Alternator at the WP.
This is the BACV to WP hose.

Would this be significant enough to cause the symptoms of overflow and bubbling?

REW138

So I cleaned all the crud off.
​​​It seemed to just be surface build-up.
I used brake cleaner and some 180grit to bring the pipe back with the hose still attached - as I reckoned I could get it done without removing it.

The hose itself is still in great condition, so if I can avoid buying a (super rare by the looks of it in AUS) new OEM one, I will.

I popped the hose clamp all the way off to achieve this and I now think I might have to replace that, lol.

But I managed to crack the seal for the hose itself and get it firmly and completely back all the way on the pipe - not sure why it was that far off to begin with.

I don't quite trust the hose clamp any longer, although it is on there without budging, so I think I will wait until I replace that.

Then I will put it all back together and push it out the carport to bleed coolant again.

Fingers crossed, although I still have this eerie suspicion that it's something more sinister.

WondrousBread

The engine that came in my car also had no signs of coolant seal failure. Started and ran normally, no overheating, etc. When it eventually lost compression and I opened up the block, there were broken coolant seals in three different places (and I think at least one place where the groove itself had broken. Strange how it sometimes causes no symptoms.

REW138

Is loss of compression a symptom, or are you saying that was what drove you to open it up?

WondrousBread

The second one. It was unrelated compression loss that drove me to open it and find the coolant seal failures.

REW138

Ah, righto. That makes sense.
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REW138

Just to circle back...

diabolical1

iTrader: (3)

ouch!

it sucks, but at least now you know what it is. are you going to replace it or have it repaired?

REW138

It is currently being rebuilt - replace that iron...

Not cheap, but that's the nature!

Got diagnosed a while back, I just thought I'd update the photo as I referenced it in a Reddit post.