[ossi1]

This caught me by surprise last night.

Earlier in the day I had done a 70 mile ride up the motorway just taking it easy. On the way home I gave it some of the right foot so was averaging 70/80 and on occasion some more.

Needless to say it was a continuous journey of about an hour or so so everything up to temp.

When I got home I noticed a trail of water up the road and onto the drive. On closer inspection the rear left was dripping continuously, literally drip drip drip.

It didn't smell of anything. I know exhausts drip but I've never seen anything like this.

I have no warning lights. Prior to the trip the car was idling slightly rough, and you could feel it coming through the floor.

Its only on 4k miles and I've owned it from new .

Anyone had similar in relation to manic dripping from the exhaust bearing in mind after an hour or spirited driving I would have thought any moisture would have gone from the system.

[AndDown]

Are you certain it’s dripping from the exhaust? I’ve had water condensation drips onto the driveway when the A/C has been running for a bit, esp during the summer months. There’ll be a decent puddle after stopping/parking but it will be clear and definitely water condensation from the A/C.

[Zanity]

Originally Posted by AndDown

Are you certain it’s dripping from the exhaust? I’ve had water condensation drips onto the driveway when the A/C has been running for a bit, esp during the summer months. There’ll be a decent puddle after stopping/parking but it will be clear and definitely water condensation from the A/C.

I think he's saying the drip is from the exhaust tip, A/C is in front of the car, no where near the exhaust tips. Maybe the catalytic converter is acting up? But there's no codes, so that means the O2 sensors are not flooded. I don't really know.

[upsidedownfunnel]

As long as it's just water and not coolant or gasoline, you're fine. Depending on how you drive, it's possible for the byproducts of combustion to pool in your exhaust and then suddenly drip out if your car is at the right incline or when you accelerate.

H20 (water) is a natural byproduct of combustion. Completely normal. Unless you notice any other issues or if the liquid smells like something else, i wouldn't worry.

[Wgosma]

Have you checked the level of coolant in the expansion tank?

Head gasket failure often shows as white (steam) exhaust from tailpipe- this doesn't sound like that, very unusual, hmm....

[Zanity]

Originally Posted by Wgosma

Have you checked the level of coolant in the expansion tank?

Head gasket failure often shows as white (steam) exhaust from tailpipe- this doesn't sound like that, very unusual, hmm....

it's a new car with 4k on it, i dont think it's a head gasket lol, I know bmw isn't the most reliable but come on. I still think it's catalytic related, maybe it's being broken in.

[Wires]

If the air is more humid, you will get more water from the exhaust.

[Billfitz]

One of the products of the combustion of hydrocarbon fuels is water, the result of the hydrogen combining with oxygen to create H2O. Perfectly normal.

[bimmer456]

I always thought the CAT was what produced the water.

[Mr Podman]

Your car was happy you stretched it's legs. It was salivating with joy.




podman

[Billfitz]

Originally Posted by bimmer456

I always thought the CAT was what produced the water.

A CAT increases the amount of water produced by combining unburned hydrocarbons with oxygen, but the main source of water is the combustion in the engine. All hydrocarbon combustion produces water, including the oil or gas furnace in your house. You're not aware of it because it goes up the flue as water vapor. With a car some of that vapor cools enough by the time it reaches the tail pipe to condense to liquid water.

[ossi1]

Originally Posted by upsidedownfunnel

As long as it's just water and not coolant or gasoline, you're fine. Depending on how you drive, it's possible for the byproducts of combustion to pool in your exhaust and then suddenly drip out if your car is at the right incline or when you accelerate.

H20 (water) is a natural byproduct of combustion. Completely normal. Unless you notice any other issues or if the liquid smells like something else, i wouldn't worry.

Thanks for the replies everyone. Yes as I turn into my house I drive up an incline and the car is then parked on my sloping drive, so I guess that could explain the possible release of the water if it had pooled.

We just thought it was a hell of a lot but perhaps circumstances dictated its sudden release ie the slope. No smell to the water.

No worries then cheers.

[pjkbrit]

My new 340 produces tons of water also. Probably normal...

[MmmmmM2]

Originally Posted by pjkbrit

My new 340 produces tons of water also. Probably normal...

Hmmmmm...My ZHP does not. Odd?

[XutvJet]

The cat converter makes water as byproduct. Water temporarily gets trapped in the muffler can. Water leaks out. Science.

[paul e]

I find it odd that after an hour of driving the exhaust heat would not have evaporated the water. You see water/mist in the morning when the car first starts, but again the exhaust heat should take care of it after warming up.

I’d take it in just to be safe.

[AK415]

Originally Posted by ossi1

Thanks for the replies everyone. Yes as I turn into my house I drive up an incline and the car is then parked on my sloping drive, so I guess that could explain the possible release of the water if it had pooled.

We just thought it was a hell of a lot but perhaps circumstances dictated its sudden release ie the slope. No smell to the water.

No worries then cheers.

Where is the pool located? I believe air conditioning creates a puddle after a drive as well, at least for my lady's Infiniti.

Originally Posted by F30ZHP

Hmmmmm...My ZHP does not. Odd?

She is not happy with you

On a serious note, that is normal as well. Climate makes a difference and the H2O can definitely evaporate from the high temperature within the exhaust system.

[pshovest]

Originally Posted by paul e

......I find it odd that after an hour of driving the exhaust heat would not have evaporated the water.......

I find this very odd also, particularly after (2) 1-hour drives at 70-80MPH. However, if the car is only used for very short trips and very gently driven, the resonator/muffler can collect several quarts of condensate.
The test is to check for dropping coolant level. Hopefully car has a low coolant level sensor.

Any chance you've got a trunk/boot full of water and it's leaking out?