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Heater core flush time...

10K views 12 replies 4 participants last post by  jjpark 
#1 · (Edited)
Owned for 4 years and have experienced all the typical joys of owning a VW...fuel pump, radiator, alternator, coil pack(s), numerous window and seat switches...and etc the list goes on.
Anyways add to that list no heat...so time to flush the heater core and follow Tom VW write up.

I thought using air pressure at 35psi that was linked in the diy was too much.

I did notice this harbor freight pump hooked to a drill motor in this YouTube...seems to make sense using recycled water and clr and am asking for your comments on this pump method.
https://m.youtube.com/watch?v=M7MArQFs9Lc

Thanks in advance.
04 2.8 wagon glx 99kmiles.
 
#3 · (Edited)
After reading on Passat world its 50/50 on the clr...does it work or not....is it too strong or not... lol lots of overthinking on these cars.
For sure a big no on using a home made compressed air device.

Ill just go with chrisfix video. Real clear for a dumb truck owner like me ! Hope it works...I'm so done with this car:
https://m.youtube.com/watch?v=M9SIafVsqyc

or our very own certified PW.com dyi sticky:
http://www.passatworld.com/forums/b...leeding-cooling-system-heater-core-flush.html

Add to this per tomvw...'Do NOT use the"Singin in the rain" method, this is more likely to make it worse than better, Jay has said he has never had any success with flushing a heater core.'...ugg what is that method anyways ?

Yay found it...I'm gonna just have to decipher all the Passatworld threads.
http://www.passatworld.com/forums/b...youre-singing-i-aint-got-no-heat-blues-2.html
 
#4 ·
I would go ahead and do this. You have nothing to lose. You do not live in Alaska.

The CLR Method works just fine. It is not the CLR that you are worried about making a hole in the heatercore, it is the pressure you use with a garden hose that may be too high. Always use a steady stream with no real pressure.

I cleared out my heatercore using the 2nd link you provided. It is by far the most effective method. I stupidly bought my car with no heat. Forgot to check as this is Miami,FL. Never dips below 65f.
On Top of that, Previous owner mixed Green Coolant with VW Pink Coolant. These two together creates a brown sludge that can destroy radiators. Never Mix these two. I ended up buying a new $25 coolant tank as mine was extremely gross. I could only imagined what it looked like further down the system.


You may also want to complete a full Coolant Drain and Flush before this. I used Prestone's Flush/Cleaner product. This was really good as it took 1 Treatment and 2 additional water flushes to get rid of all of my radiator's iced tea colored muck. It eventually drained to a nice clear color. (make sure you use the 5mm engine block drain plug, and not the plastic radiator plug.) This is where all your dirt lies, poke it with an allen and watch crud fly.
This is what gets trapped in your radiator and heatercore. A proper flush will make your later heatercore flush safer as you have reduced pressure and particle size. Plus, clean coolant is a nice bright pink color!
Attempt the heatercore flush while everything is drained before your final coolant fill. Just so you dont spill shit everywhere.

Caution, Inlet and Outlet pipes on the heatercore ARE PLASTIC. You know what happens to 15year old plastic. Go buy a $1 hose pick and gently work the hoses off.

Then, do what ChrisFix mentioned. The Garden Hose backflush method. This is always a temporary week long fix that needs to be followed with CLR. This is only to prep for CLR.

Second, do the CLR drill pump method. I even used a 60clr/40wtr dilution as no fucks were given.
You will want to send water in the outlet and out the inlet (backflushing dislodges crap as opposed to pressing them in further. Make sure you use $1 Teflon pipe tape to make sure all your fittings on your pump are snug and you are not pumping in air.
Loosely tie a Cloth or a bandana with a rubber band or zip tie around your inlet tube in the bucket to act as a filter.
Pump for a mere 5-10 minutes, and go sit for 30. CLR needs to soak into the calcium deposits. The pumping is mainly to get the CLR to the sweetspot+some back flush pressure.
Repeat the pump and sit about 4-5 times.​
Get clear hoses so you can watch in disgust as brown stuff swims down your lime green CLR.
Purge out all CLR with garden hose until it runs clear.​

Now, Connect your hoses and refill your coolant. You are using Distilled Gallons of Water with G12/G13 Coolant Right??
(Keep cap open). Get ready to open a bleeder screw or two until air bubbles disappear from the screw opening and a tiny stream flows. (This means theres no bubbles in your lines,[air insulates, not transfers heat])
Crank Your heat up to high and feel the goodness.

I typed this up real quick and may have left out stuff. Please reply if you have any questions. Ill be sure to answer.
 
#7 ·
(make sure you use the 5mm engine block drain plug, and not the plastic radiator plug.) This is where all your dirt lies, poke it with an allen and watch crud fly.

Caution, Inlet and Outlet pipes on the heatercore ARE PLASTIC. You know what happens to 15year old plastic. Go buy a $1 hose pick and gently work the hoses off.
Where is the engine block plug on the 01 Passat. Also. What you mean $1 hose pick? I have a feeling my plastic pipes might break when I try to remove the hoses.
 
#5 ·
Yes, recirculating filtered water makes sense in drought stricken ca!
Going to get some clear plastic tubing for my viewing pleasure.

Our PW sticky covered too much with too few pics...and got me a bit confused...especially the link to a home made compressed air device, mixed in with the option to remove the core and the stand on your tippy toes and pat your head to bleed the lines.
The 'singing' write up I stumbled upon I could follow.
Also the recirculating pump was mentioned within the thread.

Still unsure of the benefit from those that say to reverse the process.
I'm typing fast also on a phone but just wanted to thank you for the reassurance.
 
#6 · (Edited)
Auto part Vehicle Automobile repair shop Wheel Automotive window part


Tire Automotive tire Wheel Alloy wheel Auto part


Auto part Wire Cable


Got heat.

The harbor fright drill pump was as expected junk.
Flushed about (3) 5gal buckets with a water hose.
A fair amount of sediment came out, not turd like chucks but sandy with scales.
Disconnected the water hose and poured clr directly into inlet.
I hooked up a small sump pump in a nylon breathable shopping bag and set inside a 5gal bucket.
I let the solution recirculate through the heater core using just the 5gal bucket...
while I replaced the washer pump.

This is the great beauty of the Passat...while you fix one thing you can fix yet another thing :)
Thanks for all the tips and resources
 
#9 ·
Correction it is not 5mm. It is an 8mm Allen Bolt.
There is a 8mm Allen drain plug on the back side of the subframe cross member offset to the drivers side. It is recessed about 1 inch into the casting of the engine block. You'll probably need a flash light to find it.

Auto part


This is seriously where all your sediment lies! I had to poke it with the allen wrench to let coolant flow out. It was so grainy and sooty. This results in a clear water draining when you flush it.
 
#13 ·
2002GLXV6

Thank you for that link. I'm FINIALLY finished with completing the front suspension/ rear shock work. Only took me a few months from originally starting it (either too rainy, too cold, or other life happenings). 1st time ever doing this on a VW and it actually wasn't too bad of a job.

Total time to do the actual work? ~ 8-10 hrs (that includes multiple trips from under the car to the tool box to find the right tools, a few trips to the parts store etc) DIY saved me over $1000
 
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