I don't see where VW has an interval for coolant replacement for our 2021 Jetta 1.4 TSI. We plan on keeping the car for up to another 5 years. It currently has 60,000 miles. My current inclination is to do a drain and fill at home. My question is, is this overkill and totally unnecessary or is it warranted. Our 2014 Jetta ended up with a plugged heater core at 40K miles. I'd like to avoid such an issue if possible. Thanks!
2021 VW Jetta coolant interval
- Thread starter gregk24
- Start date
I think 60,000 miles is reasonable for a coolant change.
Clogged heater cores can be attributed to the silicate pouches VW put in the coolant reservoir tanks. I took them out of our 2020 Tiguan.
Agreed with ^. Regardless what manual says (i.e. 100k or "lifetime") I would do ~5/60 on any car. IMO coolants continuous heating and cooling cycles combined with exposure to mixed elements (Iron, Aluminum, Plastic, silicone, rubber) has to take a toll on its longevity and long term viability. (FWIW, I don't care about the price, I only buy coolant from the dealer. And if it's not pre-mix I use distilled water from the store.)
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I also only use OE coolant and purchase from dealer.
edyvw
$50 site donor 2026
The biggest culprit was BG flush treatment.
This very well could have been what caused it. Water pump was leaking around 35k miles, took it in under warranty and i do recall they did a “flush” with some additive after. A few months later heater core was clogged. Not covered under warranty.
edyvw
$50 site donor 2026
So, I had recall on water pump around 64k (car has 112,000 now). Got to dealership, guy is trying to sell me BG. I read on forums they were failing after flush.
So, I told him under no circumstances they can do that, because I don’t want clogged core. And service advisor is: “yeah, I know.”
What chemistry coolant is VW using? Of course being this is BITOG we would want you to send a sample out for coolant analysis.
Can you get to the block drains? Doing a plain drain and fill probably gets only 50% of the coolant.
What about changing the coolant to Ford yellow?
Can you get to the block drains? Doing a plain drain and fill probably gets only 50% of the coolant.
What about changing the coolant to Ford yellow?
Do what I have done with my current two VWs (signature) and the two diesels that preceded these. You should have an overflow tank through which the coolant flows when driving. I buy a gallon of VW coolant at the dealer and then suck the old coolant out of the overflow tank (mine has a pressure cap) and fill it back up with fresh coolant. I do this maybe 5-6 times a year. My overflow tanks are extremely clean, my coolant is bright pink and no difficulties. Each time I do this I remove over a pint of coolant and replace it. 6 times a year...3 quarts of replaced coolant. This way, no worrying about getting air out of the system. This costs me less than $30/year.
My advice, change it now and then go on the replacement routine after about six months.
My advice, change it now and then go on the replacement routine after about six months.
Si-OAT. (Glysantan G40) for the affected model years. I wonder if the interval was simply too long and the protective layer was sloughing off?
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Current VAG G13 (violet) is a glycerin based organic acid technology coolant with low silicates (Si-OAT), and no phos, nitrates or amines. It's a very long lasting fluid, but doing drain and fills on a regular basis (5yr-60K) will keep the system clean, fresh, and working well for many years. Never found the need for a full system flush if this is done. Waterpumps on the other hand.........
I would NOT recommend mixing this with any other fluid. It's very easy to source and not hatefully expensive, so no reason not to source it or try something else.
I've heard of a few others that do the "suck and replace" method and have nice clean systems too. I'd forget doing it that often though, age
.Another fellow VW owner I know does a somewhat novel method. Once the car is warmed up and thermostat is open, heat on full, he removes the return line from the coolant reservoir and routes it to an empty bucket. Starts the car and pours coolant into the reservoir while the return hose pumps out old coolant. Does this until he gets about a gallon, then reinstalls return line.
After driving, my reservoir is extremely hot to the touch, so much so that I would get blisters if I held on to it right after I shut the car down. o excellent flow in the VW system. I have never had a cooling system leak not have I replaced a water pump in those cars.
It's a closed, constant flow system, so I imagine the flow is sufficient but not firehose overpowering or something like that. I'll have to ask to get specifics from the guy that does it. I always take off a lower radiator hose to drain (when cool) and it dumps about a gallon.
Compared to 2014 VW is using a slightly different coolant for your vehicle but I would change every 4-5 yrs. It's not expensive.
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