DIY: Heater core replacement

[Top_Fuel]

...guess who discovered they get about 30 degrees less from the right side than from the left?

The condition develops slowly over time. Unless you live in a cold climate and have a front passenger who complains of the lack of heat, it's easy to dismiss the problem. It's just a small car with a tiny engine...so you almost expect poor heat output, right?

I have measured my heat output the last 3 winters. And when I say "measured" I mean I drive around with thermometers in my dash vents constantly under controlled conditions for days at a time. My heat output temps have declined by a 5-7+ degrees every year. I'll be testing it again this year as soon as we have a serious cold snap.

[AtomicPunk]

The condition develops slowly over time. Unless you live in a cold climate and have a front passenger who complains of the lack of heat, it's easy to dismiss the problem. It's just a small car with a tiny engine...so you almost expect poor heat output, right?

I have measured my heat output the last 3 winters. And when I say "measured" I mean I drive around with thermometers in my dash vents constantly under controlled conditions for days at a time. My heat output temps have declined by a 5-7+ degrees every year. I'll be testing it again this year as soon as we have a serious cold snap.

So what has been the findings on this? No amount of flushing will get the goo out? Is it only a matter of time on all years?

[Wallythacker]

I'm hoping it happens over time to all years and models. Mitsubishi won't be able to deny there is a problem if it becomes that widespread. All car makers need their feet held to the fire if there is a known issue with thier cars that they are choosing to ignore.

TF, wasn't your heater core replaced 2-3 years back?

[Dirk Diggler]

The condition develops slowly over time. Unless you live in a cold climate and have a front passenger who complains of the lack of heat, it's easy to dismiss the problem. It's just a small car with a tiny engine...so you almost expect poor heat output, right?

I have measured my heat output the last 3 winters. And when I say "measured" I mean I drive around with thermometers in my dash vents constantly under controlled conditions for days at a time. My heat output temps have declined by a 5-7+ degrees every year. I'll be testing it again this year as soon as we have a serious cold snap.

Even with the passenger vent blowing cooler on a cold day wouldnt the cabin eventually get to a comfortable temperature? Another question, say you had to do a bypass because of a faulty heater core, if you just drove for awhile wouldnt the cabin heat up because of residual heat from the engine and human body heat? Just curious.

[Top_Fuel]

So what has been the findings on this?

Here's the "unofficial" official answer...

An internal restriction on the passenger side of the heater core is the cause of reduced heater output. The restriction results from an unknown substance collecting on the outlet side of the heater core passages. The material collects primarily on the passenger side of the heater core.

Here's the substance on Doax's heater core...

Here's is what BASF said when foama sent them the picture above...

“We can't say anything definite without an analysis of the material. However, the substance may be created within the heater core itself, the cause being residual substances used in manufacturing that react with the OEM coolant and subsequently deposit the reaction product on the colder, outlet side of the heater core. We recommend replacing the affected heater core and using Glysantin G64 coolant in the future, which was designed specifically for preventing such deposits.”

In other words, it might be flux or some other manufacturing material that collects on the outlet of the passenger side of the heater core. But we haven't come up with a chemical that can remove it. VW had the same issue with some of their own vehicles, and the ultimate fix was to replace the heater core.

Is it only a matter of time on all years?

I don't know. We know for sure that there are 2014 and 2015s out there with the problem. Everyone who installs a new heater core reports a "night and day" difference in their heater output. I don't think anyone with a 2017+ has done any serious testing.

...wasn't your heater core replaced 2-3 years back?

It never got replaced. Read about my ordeal here.

[Top_Fuel]

Even with the passenger vent blowing cooler on a cold day wouldnt the cabin eventually get to a comfortable temperature?

It might in Atlanta. Ask someone from Canada how important good heat output is when it's -30 degrees outside!

[Wallythacker]

Here's the "unofficial" official answer...

“We can't say anything definite without an analysis of the material. However, the substance may be created within the heater core itself, the cause being residual substances used in manufacturing that react with the OEM coolant and subsequently deposit the reaction product on the colder, outlet side of the heater core. We recommend replacing the affected heater core and using Glysantin G64 coolant in the future, which was designed specifically for preventing such deposits.”

It never got replaced. Read about my ordeal here.

So BASF say they don't know what the deposit is without testing yet they can reccomend something they make to ensure said deposits, which BASF say is undefined, never occurs. I call pure bull**** on that.

I guess I have lost about 3-5F over two years. I bought two meat thermometers when TF was having issues to see if I was in ttrouble on my '17. I found my notes and did indeed, have 167F from the left and 168 from the right.

[Top_Fuel]

So BASF say they don't know what the deposit is without testing yet they can reccomend something they make to ensure said deposits, which BASF say is undefined, never occurs. I call pure bull**** on that.

Before you dismiss what BASF said, VW had a major problem with the same thing a few years ago. I posted the TSB on the forum (but I can't find it right now for some reason). The explanation in the VW TSB was almost word-for-word what BASF said. The material is some sort of material left over from the manufacturing process of the heater core. That's why it's only in the heater core and not the radiator.

[Wallythacker]

The other thread that's now at the top has the VW tSB.

I contend if BASF doesn't know what this goo is then how can they recommend a product to prevent it from happening again? What evidence do they present their G64 will eliminate this? None. Seriously, it smacks me of a Dr. telling you he doesn't know what type of cancer you have but if you delete "X" from your diet it will never return. Neither passes the smell test.

OTOH, if BASF knows what this deposit is, why can't they, as the world's largest coolant maker and one of, if not the best, chemical firm on the planet, engineer a coolant or flush that will break down the deposit?

I feel at this point BASF is complicent with the car makers for knowingly selling a product with established defective properties.

[Eggman]

The other thread that's now at the top has the VW tSB.

I contend if BASF doesn't know what this goo is then how can they recommend a product to prevent it from happening again? What evidence do they present their G64 will eliminate this? None. Seriously, it smacks me of a Dr. telling you he doesn't know what type of cancer you have but if you delete "X" from your diet it will never return. Neither passes the smell test.

OTOH, if BASF knows what this deposit is, why can't they, as the world's largest coolant maker and one of, if not the best, chemical firm on the planet, engineer a coolant or flush that will break down the deposit?

I feel at this point BASF is complicent with the car makers for knowingly selling a product with established defective properties.

I'm not sure we can blame BASF for this... lol