1719matt

The last two times I’ve taken my car out, I’ve had tiny water droplets on my windshield like it was a slight drizzle, but there was not a cloud in the sky. (The amount of water is very slight, like when someone in front of you hits their windshield wash and some gets on your window).
Do I have an issue? Do I have a leaking radiator or AC problem? The last two times I drove it was very hot and humid out. The water temp, oil temp, etc. seemed fine.
Any thoughts?

1719matt

To clarify, water is spraying on my windshield from somewhere. Possibly a leaking radiator or AC condensor, but not sure. Anyone have else have this problem?

LexVan

Have you washed your car recently? Residual water??

1719matt

Possibly. It's been over a week since I washed it and have driven it twice, but I suppose time will tell.

Yet anothercrisis

I would check headlamp and windshield washers for leaks.

Good Luck

wwest

"..HOT and HUMID out.."

Where?

Happened to me about 8PM, just after dusk, in Alabama after a HOT day and late afternoon showers.

HVAC system is COOLING the interior surface of the windshield (WASTE of cooling efficiency) so you need to over-ride the system and turn off the CHILLING airflow going through the defrost/defog/demist ducts. Otherwise just use the wipers.

wwest

....

GSIRM3

Maybe your windshield washer is leaking slightly. I doubt a leaking radiator would cause the problem you describe, and for sure a leaking AC condenser would not put water on your windshield.

Tcc1999

I dunno' but you said hot and humid so I'd guess Condensation. Hot air holds more water than cold air (which is why you seldom hear cold and humid unless you are in a cave for example) and the water will fall out of the air or condense when cooler air, or a cooler surface is present. (Think of the water droplets/moisture that forms on the outside of a bottle of water on a hot day.) So, if you have your a/c blasting, particularly if the cold air is being directed from the top vent, the windshield might be cooling enough to facilitate condensation.

Or it could be what you said, wiper fluid or radiator fluid. If its either just stop and smell it next time - they do have district odors (I wouldn't taste it, particularly if you think it could be from the radiator!).

Good luck.

Macster

Coolant would not dry clear but leave a stain. Same for the washer fluid.

Someone in front of you hit his car's windshield wash button.

Or the car in front of you dribbled some evaporator water from under the bottom of the car.

Open the front trunk and make sure the water drains are clear and there is no water accumulated.

I had two radiators suffer severe damage and in both cases bad enough to the have the cooling system emptied in just minutes and have yet to have one drop of coolant get on the glass or on any painted surface.

Mumbles

Someone in front of you hit his car's windshield wash button.

x2

1719matt

Its exactly like the car in front of me hit the windshield wash, but its not. It's not my daily driver but it's happened a few times now. The condensation thing could be it. I'm in CT and the weather hasn't changed since I first posted. Its very hot and very humid. I'm glad to hear radiator fluid and AC condenser are unlikely.

Macster

Well, they are not completely out of the question. If you are sure the car in front of your car can't account for the water or if this happens when there is no car in front of yours and you are not driving where perhaps A/Cs from multistory buildings can't rain down water from the A/C, there could be a radiator or an A/C problem.

You can drive the car around with the A/C off and get the car the engine up to temp. Then at a convenient spot raise the rpms up to 1500 and hold until the radiator fans come on. Then shut off the engine. Let the heat of the engine raise the coolant temperature and pressure. If there is a leak that could account for the water on the windshield you'll know it.

As for the A/C... water is not a fluid in the system so a leak is not possible.

There could be a problem with the evaporator that has the normal condensation not draining from IIRC a catch pan that then has a hose that lets the water run down under the car. I see this whenever I turn my car sharply at slow speed, there's often a trail of water from this drain hose when the A/C is on (which sort of suggests my car's drain may need attention...the fluid should drain without the benefit of high g-forces).

Perhaps the drain hose is blocked or the drain hole is blocked and condensation accumulates and then overflows and is somehow carried to the windshield. For the condensation to accumulate is not that far fetched. But it is quite a far fetched scenario for it to somehow end up on the windshield.

Also it is very important you verify the water drains are free and no water is accumulating. This can possibly have the wind kick up some water and the drops hit the glass. I'd think the water would be getting into the cabin first but maybe not. Regardless eliminate any water at the drains and their catch basins.

Last but no least... are you sure you are not hitting the windshield washer button? I have never tried this but it might be possible to hit this quickly enough or in such a way which can trigger the pump but not the wipers.

wwest

Once the cabin atmosphere is initially cooled down nearby your setpoint the Porsche A/C system takes several measures to prevent driver/passenger discomfort from COOLand DRY system airflow directed to the face and upper body.

To more widely spread the dispersion of system airflow ALL outlet vents are opened thereby allowing the blower speed to be lowered significantly.

If the radiant, sunshine, cabin heating effects are of a serious nature then the system outflow temperature will be somewhat CHILLING.

So within a few minutes or so of driving the windshield will be quite COLD in comparison to the HOT and HUMID ourside atmosphere. Humid enough, you will begin to see water droppetts forming near the bottom of the windshield, the COLDEST point on the windshield.

The only practical solution that I have found is to manually "enable" the upper system flow, and then disable it. That action takes the upper outlet out of automatic control mode. Longer term, tinting the side and rear will be of help to lower the radiant heating effects and thereby allow you to make use of a slightly higher temperature setpoint.