Coolant loss, 15 Jetta

My 2015 has slowly lost coolant since it was new. Probably when it had less than 5k on the odometer, I noticed the scent of coolant when I popped the hood one day. This year and at 31k, finally the coolant level dropped enough to activate the idiot light. I checked everywhere from the top and underneath. I can find no pink residue. Not too concerned about it, but th bumper to bumper is due to expire in March.

Question for the forum, have any of you added coolant to a 15' yet? I'll accept a very small amount of loss, but obviously it has to be going somewhere.

Interesting. I have the same situation. Bought my 2015 new in April. Last month at about 7200 miles the low coolant light came on. I also had been smelling coolant. Did not see a leak so took it to the local dealer in Boise, ID. First off, the service writer gave me a song and dance about "they always burn a little off" but they would check it. After not finding any leak, they told me the low level (it was at the very bottom of the reservoir) was due to the weather turning cold! Since then we made a 5,000+ mile road trip and the coolant level stayed about the same but I got a whiff of coolant smell again today.
Like you say, it has to be going somewhere!

This week is the last warmer week of the year. I plan to pull the bottom cover off and have a look for some residue. The only place I can't get a clear view is in the timing cover. I can only assume that water pump is the culprit. I'll report back.

Today I took off the splash guard and put my eyes on every single coolant connection. This is the first time I've really paid attention to it, and holy crap... It's very complex. There are probably 20 separate hoses, 5 tees, 2 auxiliary water pumps, a giant coolant/oil heat exchanger and at least 3 flanges where coolant comes in or out of the long block. Interestingly enough, I could find no obvious place for a thermostat. I assume the temperature is controlled through the water pump impeller damper.

Beyond that, I also partially removed the top timing cover. I could find no pink residue on anything... anywhere. none directly below the water pump on the side of the block, none anywhere else on any of the connectors. The system holds pressure very well, still pressurized after sitting in the driveway for 2 hours. No oil contamination... really the car starts, runs, and drives like new. Probably because it almost is new.

That said, I can only assume that a small loss of coolant over time is "normal", or that it has something to do with the integrated "exhaust manifold"... perhaps the temperatures really do get high enough to vaporize it? I don't know. What I do know is that the car is 32 months old, has done 31,000 miles and required 595ml of coolant added to the expansion tank.

I have one other annoyance I will have checked sometime before the bumper to bumper expires, I'll have them specifically check the water pump. I want an invoice from the dealer saying that the water pump was normal and not leaking.

I have a 2015 TDI 6 speed and my coolant level hasn’t changed at all in 60K. I do however use about a qt of oil between 10k service intervals.

I have already seen a couple 2015s with leaking water pumps. However, these were clearly SEEN as there was coolant residue on the bottom of the engine, under the crank pulley.

I suppose you may have to do a pressure test both hot AND cold. You said you smell it, so I would think you'd be able to find it.

The cooling system is very complex.

The main thermostat is in the large housing at the end of the large tube underneath the intake manifold/charge air cooler area. You need to remove the air cleaner assembly and the charge air tube that crosses over the top of the bellhousing to get at it.

I just bought a used 2015 TDI and I keep smelling it but I cant find it. I do notice that from time to time the cooling fans are on well after I turned the car off, I was not on it and its cool out like 60F. There is some white residue that feels looks and feels like oil that looks like that has flung off the AC compressor...

The cooling system is a closed system and you should not use any coolant. Make sure rad cap holding, is good place to start, could be faulty. If car overheating do to a faulty thermostat, which could be sometimes acting up, sticking causing coolant blowing out from rad cap I would have your cars Checked out and find out where the coolant is going. If ones car is under warranty then get the dealer to find and fix. Either way get it fixed as most definitely a problem. What ever the cause I would find and fix asap.

FXDL said:

The cooling system is a closed system and you should not use any coolant. Make sure rad cap holding, is good place to start, could be faulty. If car overheating do to a faulty thermostat, which could be sometimes acting up, sticking causing coolant blowing out from rad cap I would have your cars Checked out and find out where the coolant is going. If ones car is under warranty then get the dealer to find and fix. Either way get it fixed as most definitely a problem. What ever the cause I would find and fix asap.

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I actually had my car at the dealer today. They pressure tested it and said its fine and that there is not issue. I keep smelling coolant after the motor is hot and what looks like a leak dripping on the crank/AC pulley and flinging is a straight line on the drip tray and lower hose

Yep, that's the water pump.

Ask them to get the car on a lift with the lower shield removed and you can point this out to them.

Man... I get the feeling this is going to be a thing with the CVCA.

16vjohn, was it the water pump? I just had a few moments of smelling coolant inside my 2015 TDI ... at 5,400 miles.

The water pump is fine, no leaks. I haven't smelled the coolant since I replaced a clamp on the water cooled DEF dosing injector. There was no residue because the coolant would drip onto the DPF and burn off. Those clamps suck!!!

Did you use a stock VW clamp, or something different?

Screw clamp ala Autozone... pretty ghetto, but functional.