Antifreeze leak after cold spell
 

Went out to the garage a couple days ago and noticed a stream of antifreeze had leaked from underneath the 427.

Last week, we had temps as low as 18F amid a string of three days below freezing. The car is parked in a detached garage which is finished, but not heated. We went from a long Summer here in Seattle straight to Winter, and I have never gotten around to doing anything special to winterize - plus I usually plan to do some work on it over the colder months.

I haven't touched the coolant for a couple years other than to check levels (which have been fine). Didn't get much driving these past two summers.

Anyway, I use a 50/50 mix of green antifreeze. I've always expected that to be fine at much much colder temperatures than it ever gets here. It looks like this should be good to -10F. I have a hydrometer on order so I can test it.

It appears to have leaked from the bottom of the overflow reservoir, and also has some brown gunk - corrosion?

I popped the cap off, and the level is maybe 3/4" below the inner baffle. When I check, I'm usually looking to see if it's about level (which it typically is, maybe just a bit below? I don't remember).

I'm confused what happened here. The amount I discovered on the floor (maybe a pint's worth?) seems about in line with the current level in the reservoir, but if there's a leak there I was expecting it to be empty. This seems to have happened all at once (and has since stopped), not just a slow leak.

I expect frozen coolant within an engine block to be pretty catastrophic, but don't think it got cold enough for that. Does coolant separate while sitting ever? The engine hasn't run for several months.

What tests should I run come Spring when I'm ready to get things running again?

I can only offer hope in the form of wild speculation. Different materials expand and contract at different rates with changing temps. I wonder if a gap between differing metals that is too tight to leak at "normal" temps opened up in extreme cold. . . If I couldn't find an obvious source of the leak, I'd top it off with coolant when ready to run, bring it up to operating temp and pressure, and see if any leaks appeared. If I saw none, I'd be happy.

I would check for a pin hole around the current level in the tank. If it had frozen and leaked you should see some deformation of the expansion tank, as the liquid would have gained volume as it froze and would have had to create an opening to escape from. Unless the antifreeze had lost its capacity to withstand freezing, that should not have been cold enough to freeze it.

Jim

Assuming your "50/50 mix of green antifreeze" is Prestone (pre-mix 50/50 AF2100),
the temp range is -34F to 265F. 18F OAT should not have been an issue.

More importantly, if there's evidence of corrosion I would be concerned about
internal condition of water pump as well.

Moriarty -- your antifreeze is fine. I change mine every four years with a 50/50 mixture of the Autozone Conventional Green coolant and distilled water. I add a bottle of Water Wetter as well. For the first few years my Cobra stayed in a detached unheated garage with temperatures plunging down in to the single digits. She's now in a heated garage. Below is a picture of her overflow tank that I took ten minutes ago. That's what it looks like after almost 18 years and that's what yours should look like. What you have is a small crack along the bottom weld/solder of the tank. When the weather gets really cold the crack parts and coolant dribbles out. When the car is warm, or hot, the crack usually seals up. But, it will eventually fail whether hot or cold. Now, you could try some of those magic coolant pellets that GM uses or just pull the tank and take it to a good radiator shop and they will fix it. I would opt for the latter.:cool:


https://i.imgur.com/M02jyBq.jpg

Do not use the pellets that Patrick is talking about.....they will clog up the ports inside the tanks on the radiator....for those to work you have to get 5he motor nice in hot (230* degrees) for at least 30-45 minutes....l

Take the tank off and let a radiator shop repair....

Uhhhh, what if you hang a clove of garlic over the engine, say the secret incantation and then put two copper coins on the tops of the tires?;)

I like garlic, especially in my steak sauce ...

Damn Ed, that blows my theory that you are a vampire.....

What does someone from Gilroy know about garlic.

Patrick ....what are you trying to say.....makes no sense..??

To stop leaks on an FE one must be prepared to put a toe down the path of black magic.:cool:

Greetings Moriarty, As per the tank picture, your problem may be at the solder/weld seam. If you put your car up after a long hot run and shut down, the coolant system will build above normal operating pressure from heat soaking and could vent thru the cap into the overflow tank. BUT, with a small pin hole in a welded seam, that pressure could be released thru the seam, then drip down to the floor below. Your leak may have happen after your last outing and then discovered the other day. May I suggest bringing the engine to operating temp, shutting down and checking the seam under the overflow tank. Just a possibility and explanation. Good Luck........

I'm not sure anymore but, on certain days in Gilroy, in years gone by, it was possible to buy garlic flavored toothpaste, pastries, ketchup etc. Shucks they even used to have garlic smelling fabric softener sheets you could put in the dryer instead of the more proletariat foo-foo smelling Bounce variety.

Gilroy used to do Garlic in a fairly serious way until the Chinese put them out of business. I remember when I first moved there, I could put a steak out on the clothes line, in the morning, before I left for work and it would be marinated by the time I got home that evening. :)

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There are those who still think I am ...:)

Thanks all! Sounds like I have a trip to a radiator shop in my future. And some garlic to fix the oil leaks! Who knew?!

But before we close this chapter, I see your heater hose return feed to the water pump. That hose should be connected to the UPPER of the two heater hose connections on your firewall. The intake manifold pushes the hot coolant to the lower fitting on the heater box and the water pump draws it back via the upper fitting. Doing otherwise creates pesky air bubbles. If you have it wrong, now's the perfect time to fix it. :cool:

https://i.imgur.com/TE3ENb0.jpg

And ERA likes to use the Maradyne 5000 heater box. If you've never looked at it under the dash it has little doors that open and close. The instructions for it mirror the Ford FE shop manual instructions.

https://i.imgur.com/Wt0kXUK.jpg

"Did you know a Werewolf can kill a Vampire? I did not know this. I want to be a Werewolf" (HW) Cheers Tom.