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Black water in exhaust
Posted: Fri Apr 20, 2012 1:07 am
by iandromiskin
I suspect that this is perfectly normal but just for peace of mind - I started my car again today in the shed and noticed that the exhaust was dropping black coloured water on the ground. I know that the exhaust can collect condensation from combustion so I presume that this is normal ?????
Re: Black water in exhaust
Posted: Fri Apr 20, 2012 6:16 am
by mogbob
If everything else is "normal" with the car, i.e. it runs, performs well, not loosing water/ water on the dipstick, etc, ( ? )then as you say, it's probably down to consendsation.
If the car only does short runs then enough heat is not being generated to burn off the consendsation in the exhaust pipe.
The car is telling you it wants to get out of the shed and go for a long run to stretch it's legs !!
If there are any abnormal symtoms, report back for advice from the Forum.
Bob
Re: Black water in exhaust
Posted: Fri Apr 20, 2012 9:18 am
by bmcecosse
Blackwater is never a good sign - straight down to the Doctor's........ Oh it's from the CAR ! Good hard blast as already suggested!
Re: Black water in exhaust
Posted: Fri Apr 20, 2012 2:14 pm
by JOWETTJAVELIN
I know that the exhaust can collect condensation from combustion so I presume that this is normal ?????
If you keep on starting it in the shed and switching engine off, your exhaust will rot out in no time because it hasn't ever had the chance to warm up properly, and the engine will be fit for nothing because cold starts use a rich mixture which washes oil from the bores. If this continues and is not burnt off because the engine never warms up, drastic wear takes place.
I cringe every time I see adverts for cars which have had little use where the owner states he has started the engine every month to idle for a few minutes, wrongly thinking this is beneficial.
In the motor trade, before a lightly-used diesel goes in for MoT, they sometimes do what is called an Italian tune-up, which is basically using a heavy right foot for at least 7 miles high speed.
Do as others have suggested and TAKE IT FOR A LONG HARD RUN.
Re: Black water in exhaust
Posted: Fri Apr 20, 2012 2:56 pm
by newagetraveller
When you burn a hydrocarbon such as petrol the products are carbon dioxide and water vapour.
It the exhaust pipe is cold the water vapour will condense inside it and the soot from the exhaust will dissolve in it.
That is why it looks like black water dripping out of the exhaust.
If you take the car for a run as everyone suggests the exhaust pipe will warm up and the water vapour won't condense inside it. Otherwise the exhaust will just rust away.
Re: Black water in exhaust
Posted: Fri Apr 20, 2012 3:14 pm
by lambrettalad
yes,exhausts rust from the inside mostly

Re: Black water in exhaust
Posted: Fri Apr 20, 2012 3:19 pm
by Dean
I think we had a similar topic not long back, with the same result.
Enjoy the drive..

Re: Black water in exhaust
Posted: Fri Apr 20, 2012 4:18 pm
by moggiethouable
lambrettalad wrote:yes,exhausts rust from the inside mostly

To avoid said tin worm as an apprentice in 1974, I was instructed to pour "silvo" silver paint down a new exhaust that I then had to fit to a training instructores Toyota Corolla.
This was supposedly to avoid rot.
Prior to fitting, holding the exhaust and silencer combo vertical, I duly kept tipping paint in which dribbled into a tin on the floor, rotating the pipe and swapping tins until eventually it coated all the pipe inside and I ran out of paint.
Leaving it to drain overnight,the following day I fitted it and backed the car outside of the garage in to the car park, which housed all the company rovers and jags, revving of course as only a seventeen year old could.
Imagine the lead mechanics delight when he discovered that the paint had in fact collected in the silencer box and in executing a superb display of three point turns, I had duly sprayed silver go faster stripes down all the company vehicles doors.

Re: Black water in exhaust
Posted: Fri Apr 20, 2012 4:24 pm
by bmcecosse
Hahahahahaha

Re: Black water in exhaust
Posted: Fri Apr 20, 2012 7:53 pm
by JOWETTJAVELIN
And did it preserve his exhaust? In theory it would work... but we all know about theory.

Re: Black water in exhaust
Posted: Sat Apr 21, 2012 12:07 am
by moggiethouable
JOWETTJAVELIN wrote:And did it preserve his exhaust? In theory it would work... but we all know about theory.

Who knows?
I doubt it, but it was a real education and part of my apprenticeship that always brings a wry smile to my face when I am left alone to ponder.