Massive Coolant Loss- What To Do?

MarkG · Post by **MarkG** » 16 Jul 2019, 05:08

Hello! First time poster here.
I have been all over the internet since this incident happened 2 weeks ago. I of course found Robert DIY and have learned a lot from his videos.
The car: '93 850 sedan automatic 100k miles. It was recently given to me by a woman who tells me it has always been well maintained by a dealer and kept in a parking garage. She gave it to me after she bought a '95 850 turbo from a guy in Florida.
The incident: not knowing the implications, while driving on an expressway in Connecticut I saw what I thought was a radiator light go on (it was the low coolant light), but I drove on for almost 5 minutes until the nearest exit. There I found the coolant reservoir to be empty. Then I noticed that under the mat on the driver's side the carpet was soaked. Looking for the source, I peeled away the carpet and then the panel behind it and found what I later learned was the heater core, weeping coolant out the bottom. I walked to a gas station and bought some coolant and some water. I poured a pint of water in the reservoir and watched it disappear. After a few minutes I tried another pint, which disappeared. Over 40 minutes I poured about a gallon of water and coolant in, all which went away. I left the car where it was and phoned my wife, who drove an hour to pick me up.
Eventually I found out online what had happened (heater core failure), but didn't understand the full implications of it then. I found out from one of Robert's videos how to do a bypass of the heater core, and how to inspect for a breech of the head gasket that lets combustion gases out into the coolant, and decided to try those things.
Next day, after the bypass and the inspection, everything seemed to be ok. I drove the rest of the way back home, about an hour.
Once I learned how serious a sudden big coolant loss can be, I got a block tester kit and a cylinder test kit and performed those tests. There doesn't seem to be any indication of a bad head gasket, everything seems to be ok.
My question: everything I've learned seems to say that this engine should now be in bad shape due to an overheat: blown gasket, warped or cracked head or block. what else can I do to verify the health of this engine, before I can take the car on a heretofore planned 4000 mile trip in a few weeks?
Thanks for bearing with me,
Mark G

Post by **ZionXIX** » 16 Jul 2019, 06:46

Did you notice the engine temperature climbing during your 5 min drive?
Otherwise replace the heater core or bypass it. Then fill it with coolant and see if it holds. The heater is quite low compared to the rest of the cooling system and will drain most of your coolant. It may take more than a gallon to fill up.

Post by **Clemens** » 16 Jul 2019, 07:02

You might have been lucky. If it acted normally on the drive home you might have a chance of getting away with this. I´d try to replace the heater core asap, refill with 50/50 mixture of coolant and water and drive for a few times. First only shorter drives, then maybe an extended one. I´d try to get as many miles on the car before doing a 4000 mile trip with it, honestly.
Always check teh coolant reservoir for oily or milky residues. If not, your gasket should be okay.

greg850r · Post by **greg850r** » 16 Jul 2019, 07:04

ZionXIX wrote: 16 Jul 2019, 06:46 Did you notice the engine temperature climbing during your 5 min drive?
Otherwise replace the heater core or bypass it. Then fill it with coolant and see if it holds. The heater is quite low compared to the rest of the cooling system and will drain most of your coolant. It may take more than a gallon to fill up.

I second this advice. The sensor is at the bottom of the reservoir tank, which is level with the top of the system (designed to alert you while the block is still full). It is possible you were OK to go 5 more miles after the light came on depending on the rate of loss. I would bypass and drive it as much as I could before the trip. If no sign of a problem, I would go ahead and take it.

Post by **erikv11** » 16 Jul 2019, 09:42

I agree with the others, good posts. Maybe do the combustion residue test on the coolant one more time after you've put on some miles.

callahanoffroad · Post by **callahanoffroad** » 17 Jul 2019, 16:51

I agree as well with the consensus as well. I had this exact situation happen to me (except I was at work and was on my way back to pickup some more pizzas). What I did was grab some 5/8" heater hose bypass the heater core to make a U, Fill the rezzy and got back to delivering. I felt like mcguyver all I had was a multi tool... Hahaha

But seriously you're probably good to go once you get a new heater core. I've replaced my heater cores in both of my Volvo's. Just like the timing belt, pcv, etc it's kinda like you aren't a Volvo owner unless you have replaced a heater core.

My buddy who is an American car guy didn't understand why it mattered that the heater core was busted until I explained that there was no check valve and that the heater core ran straight off the block. Of course he also kept looking for a sixth spark plug on my engine so there's that...

Post by **MoVolvos** » 17 Jul 2019, 21:52

-
It's best to leave the bypass in and do the repairs after your trip. Keep driving it and checking every so often before the trip. No heat needed anywhere this time of year even in the evenings, unless?

MarkG · Post by **MarkG** » 21 Jul 2019, 20:10

Thanks, all, for your replies!
In reply to you:
-No, I was not savvy enough to look at the engine temp gauge at the time!
FYI: I could not get the quick release hose connections loose at the fire wall, and I'd studied Robert DIY's video for that as part of doing the bypass; they were stuck. So I used the 12 inches of hose I bought to directly connect the 2 ports off of the block. This has worked fine. I'm considering that when I install a new heater core this fall, I might do what others have done, and just run long hoses from the block, through the fire wall, to the old tubes cut short, into the core. Q: what do people use at the fire wall to fill the passage hole, or do they?
Update: I have done what some have suggested: just doing a little driving, checking my coolant for any abnormal level rise, or bubbles, and checking for milky oil. Everything has been fine, knock wood. Today I did a 280 mile drive in 98 degree weather, and still everything seems fine.
-How did I not overheat and have damage when I lost all that coolant when the heater core failed, and I drove almost 5 minutes after the low coolant light went on ?- -Any other thoughts, I'd be glad if you let me know.
You'll be hearing more from me on this forum, there is lots I'll be needing to do for this car going forward!
Thanks all, Mark G

Post by **Clemens** » 22 Jul 2019, 14:42

I guess it was pure luck and maybe still enough water in there that kept the teperature just below havoc.

Post by **MoVolvos** » 22 Jul 2019, 20:56

Clemens wrote: 22 Jul 2019, 14:42 I guess it was pure luck and maybe still enough water in there that kept the teperature just below havoc.

+1

Yes, even if the car was going down a hill for endless miles and receive convection cooling (wind) you must have fluid to cool and recirculated around the block to remove the heat. Good providence!