Yes, I agree. What would be the cause I wonder.
Certainly would not assist with bleeding the system.
Pump is pumping, coolant liquid takes path if least resistance…up and out the open fill point on the crossover pipe. The v12 is nit intended to be coolant serviced while running
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Any air may have a hard time bleeding out of engine block…these jiggle pins are for when the car is cooling down after a run, the air can get out. Needs to be at top where the air is. Could contribute, put in right way, get car warmed up, let sit overnight.
Yeah, like i said before, i thought you were supposed to fill/bleed cooling system with engine off…of course coolant will come out of filler neck if cap is off and it’s idling. Is this what happened?
Here’s what I experienced, and then what fixed it - thanks to all the help from this forum…
I put coolant flush in for a couple weeks before getting ready to do a coolant hose change and cleaning. New thermostats ready to go, also.
Wanted to run the car for a few weeks to run the coolant flush through the system, and then clean and replace.
I’d run the car daily, but nothing hard. After awhile, coolant leaks from the crossover pipe cap. I ordered new caps. Got new caps, put them on and worked great, was just about to start the coolant hose replacements when… Was doing a last run letting the beauty get to operating temp in the drive way on a Saturday, before starting the maintenance on Sunday when…
The upper A bank radiator hose blew apart. And I mean blew apart.
That’s when I learned about the atmospheric tank. What happened to me was that I had severe pressure buildup that caused the oldest, weakest coolant hose to blow.
After cleaning all the coolant stuff, new hoses, new thermostats, cleanup and replaced hoses to atmospheric tank, I haven’t had any problems.
There’s a lot more to this and could definitely speculate, but that’s the essence…
I think my first freak out thread was this The Great Coolant Line Blowout
Very interesting, I had my upper right (a bank) rad hose burst as well. I didnt mention it as I thought it was just old. (my bad) Ill get to that atmospheric tank and report back.
I was surprised also when the damn thing blew - just lucky I had the hood mostly down.
I was working a ton of things on the car at the time, but I’m pretty sure it was the Thermocure I put in that dislodged a bunch of crap and blocked up the already collapsed pipe to the atmospheric.
I was also replacing the primary yellow fan with an electric, new stats (see great coolant blowout part 2 for that mess with the snapped bolt to the housing), removed aux air assembly, and on and on… So I couldnt definitively say.
When you mentioned leaky caps, that sounded exactly like what happened to me.
No it would not, but it may leak.
When you bleed the system you do it with both caps on.
Also, the center cap is total seal and if there is excess pressure it’s the header tank cap that would release it. Does your center cap have a top seal?
Check your lower radiator hose (suction hose from the pump) it might be collapsing at high RPM. Normally it has a big spring inside to prevent this but it rusts.
Mine was overheating on highway speeds and it was a severely blocked radiator. When was the last time it was checked/cleaned internally and externally?
And a bleeder valve at the heater hose will make your life easier.
95k miles and no documentation of the rad ever being pulled and cleaned. I read I should pull and bring to a rad specialist.
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Yes you should, before anything else.
Just an update for anyone interested.
Every piece of metal on this cooling system was rusted and clogged up. Had the rad re-cored and all hoses / air bleed pipes replaced and or cleaned. Runs like a champ now.
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Ditto. But I have quite a steep driveway so I just park at the steepest point…