I did a coolant exchange on my wife’s 2021 Jetta 1.4 this morning. Someone on here mentioned this method and it truly was so easy. Disconnected the return line to the expansion tank and routed the old coolant into some plastic jugs. While draining the old coolant I added new coolant via the expansion tank. The whole process took about 30 minutes. Much better than dropping a radiator hose. The car sits at 60,000 miles and this is its first coolant change. Just paid it off so this one of the items I wanted to check off as we plan to keep it for another 3-5 years.
2021 Jetta coolant exchange.
- Thread starter gregk24
- Start date
Very cool. Once the hose is connected, do you just keep filling the reservoir until clean?
Yessir! I did rev the engine to 2500 rpm a few times to speed things along. Would have been easier with 2 people but by no means difficult by myself.
How long did it take?
About 30 minutes
That's neat, I'll have to give it a shot. Thank you!
Does your expansion tank have a silicate bag?
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SilentType
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Maybe this thread:
https://bobistheoilguy.com/forums/threads/2021-vw-jetta-coolant-interval.404244/#post-7507137
Actually talked with the guy that told me about it. He got similar results as yours and said as long as the reservoir doesn't go dry and suck in air, you're good. I'm going to try this on my next coolant change (which is coming up) and use a Lisle funnel on the reservoir. Did you cap off the inlet to the reservoir that the return line attaches to, or just leave it open?
SilentType
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Here's a link to my thread:
https://bobistheoilguy.com/forums/threads/coolant-concentration-tester.401311/
I did not cap off the return inlet. Don't know that it would make much difference either way, however that coolant filler funnel looks like a good idea, might give it a go when the weather gets warmer.
https://bobistheoilguy.com/forums/threads/coolant-concentration-tester.401311/
I did not cap off the return inlet. Don't know that it would make much difference either way, however that coolant filler funnel looks like a good idea, might give it a go when the weather gets warmer.
SilentType
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Did you run distilled water first to flush the cooling system?
I did not. I thought about it but ultimately decided it wasn’t necessary as most of the old coolant is pumped out through this process.
Maybe! I did hold the rpms around 2500 a few times to keep things moving.
Ah, must have missed that one. Good work. I think you surmized the flow stoppage correctly as the thermostat shut off the flow due to the cool water going in. Makes sense. The Lisle funnel I use works like a charm too, and makes filling/burping a snap.
I've never done a full water flush on any of my recent cars, just drain replace with fresh coolant. Was always concerned I would never get all the water out and throw off my concentration drastically. For the past several times, it's just VW concentrate from the dealer mixed 50/50 with deionized water or Pentosin premixed stuff. Gonna try the return line trick on the Tig in a few weeks.
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