[trioxin245]

Hey all,

it's been many years since I've been on the forums, mostly in the B4 subforum when I owned a 1995 Passat VR6 Wagon. Well, for the past year I've had a 2003 Jetta Wagon, 2.0L auto with 108K, and it's been relatively dependable apart from the usual stuff that wears out. But, I'm trying to figure out what's going on with the coolant.

The car has had some coolant system repair work in the past: thermostat, reservoir tank, various coolant lines, water pump. For the the past four months, I've noticed the coolant level will be below the minimum. I would add some 50/50 G12 and distilled water to top it off. I would also notice that under the car, in the center behind the engine bay there would be a very thin wet spot on the ground. It seemed to be more like brake fluid or power steering fluid in consistency, not pink like G12. It was clear and slightly oily. It seems to be dripping off the chassis directly behind the engine.

So, every two weeks or so, I would have to add more water or a 50/50 water G12 mix to keep the levels up. Occasionally the low coolant level sensor would go off and I would fill it. The car has never overheated or gone over 190 degrees on the gauge.

I've looked all over the engine bay and cannot find any evidence of a leak (unless I'm completely missing what I should be looking for).

I noticed that sometimes the leak on the ground was worse having used the A/C, so I thought it could be run off from the condensation near the firewall, possibly hitting the oily chassis before dripping on to the ground? Perhaps these are two different things happening?

Whatever's going on, I'm losing coolant on a regular basis. Any ideas would be helpful.

 

[vwgetriebe]

What I would do is get some butcher paper and set a section under the car after driving. Water condensate will only make wet spots no color, oil black, and G12 pink. The stuff you are seeing puddle most likely is AC condensate.

Did you jack the car up can remove center splash shield from underneath? By doing that you can look at the oil cooler, hoses and the block for coolant "crust" and check the water pump for signs of weeping.

 

[trioxin245]

Mystery solved

I finally have an answer. After a month or two of just filling the reservoir once a week and keeping an eye on it, I finally got enough money together to get to the shop. It turns out that some of the plastic hoses and and temperature housing on the back side of the engine block were slowly leaking, allowing a very small stream of coolant to leak out under pressure. The leaking coolant would then puddle into a small cavity on top of the transmission, where it would then overflow and drip down the trans, and then drip down the chassis in the middle of the car behind the engine. The resulting spot on the ground was always a very thin and watery-oily, which could be explained by the more watery coolant (I was just adding water to the reservoir; I didn't want to waste the G12) and dripping down a dirty transmission housing along the way.

This was a relief, as I was very worried that the coolant was leaking into the engine block, but that's not the case. At any rate, she's tip-top again with a new load of coolant and a sealed up cooling system.