It's not a terribly challenging job, so I'd flush your system. Especially since you flushed your heater core and are still having issues.
Heater Core Flush
- Thread starter blueglide88
- Start date
Ive used the poor mans version too, it has no pump, just a bucket with a pipe fitting on the bottom and put the bucket up high like on a ladder or shelf, have a pinch pliers to act as a valve.
Let it flow and collect it in another bucket,
The bucket also works a treat to fill long run cooling systems like the old toyota mr2.
Let it flow and collect it in another bucket,
The bucket also works a treat to fill long run cooling systems like the old toyota mr2.
The black gunk is usually some oil content which has reduced down and become a tarry grease, non foaming soap cleans it out. Liqui moly flush has good soaping action that emulsifies it.
Bmws are known for cooling systems issues and this is why I mandate a full system flush and clean if any thing leaks where oil and coolant are in close area like the oil filter housing or oil cooler.
One year update..........I get an occasional smell of coolant when the heater is on, yet the overflow level does not drop and the heat is awesome. So far this has been a success. 
Your heater core is leaking. It hardly takes any leakage to cause a coolant smell inside when the heater is on which won't show as a coolant loss in the bottle. As it worsens, your windows will start to steam up. I wouldn't call it a success and would prepare for core surgery.One year update..........I get an occasional smell of coolant when the heater is on, yet the overflow level does not drop and the heat is awesome. So far this has been a success.
I'm surprised that you didn't try the prestone system flush in the yellow bottle as it's designed specifically for this. I'd be afraid that clr could damage heater cores or other components
- Joined
- Nov 4, 2020
- Messages
- 104
Coolant is highly toxic, one of the most poisonous chemicals a person can encounter. Unfortunately, it really doesn't get the respect it deserves with respect to just how dangerous it is. If you're smelling it, you're breathing it.One year update..........I get an occasional smell of coolant when the heater is on, yet the overflow level does not drop and the heat is awesome. So far this has been a success.
I would give this a try...
https://parts.gmparts.com/product/a...wbQP3qJ9adFzHM45NfcmKMlCvgsw-7xx604anFFSF4ivV
https://parts.gmparts.com/product/a...wbQP3qJ9adFzHM45NfcmKMlCvgsw-7xx604anFFSF4ivV
Yea, a few drops of ethylene glycol can kill a cat or dog while a teaspoon to a tablespoon can kill a human. It kills in shockingly a similar manner as methanol does - oxalic acid crystals destroying the kidneys(MeOH turns into formic acid and formaldehyde). Alcohol dehydrogenase breakdowns ethylene glycol down to oxalic acid. Ethylene glycol was used in paint and the colorants - until recently thanks to VOC regulations.
The antidote is a shot of the strongest liquor until one gets to the hospital.
That's what someone said a year ago, yet the level is approx 1/8" down from full when hot. So it might be leaking, but at the rate of 1 drop/month. Zero condensation on the windows. Considering it's a 25 yr old vehicle that I pad $6400 for 11 yrs ago, I consider it a success to avoid a $1000+ heater core replacement bill at my local mechanic. And NO, I am not taking that dash apart myself.
I'll check in again next year and let you guys know how it's doing.
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Thank you for updating, I hope you have positive updates for years to come!One year update..........I get an occasional smell of coolant when the heater is on, yet the overflow level does not drop and the heat is awesome. So far this has been a success.
