Water Vapour
Author
Discussion

bluechim

Original Poster:

750 posts

285 months

Monday 5th February 2007
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My new VXR - picked it up on Saturday and just completed Reading Portsmouth and return yesterday and reading to Wakefield return by Nottingham today (so now covered 650 miles in total) seems to gas out a lot of water vapour when sitting at traffic lights. After a 400 miles plus run today it must be well warmed up and well cleared out? Never noticed this with my old M5, is this normal? I know it’s quite cold, and I am sure it’s only vapour, but just wondered if anyone else had noticed this? Cheers - oh yes, and its goooooood!!

o.versteer

3,338 posts

251 months

Monday 5th February 2007
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My VT2 GTS does this as well. I was slightly worried about it, but I've been told that it's not a problem. No doubt someone with more technical understanding than me will be along to elaborate shortly thumbup

ringram

14,701 posts

270 months

Monday 5th February 2007
quotequote all
by product of combustion is H2O and CO2 so when cold the exhaust condenses that water into visible steam. The cold air also does this.
Its there all the time. Just easier to see depending on exhaust and air temps etc.

bluechim

Original Poster:

750 posts

285 months

Tuesday 6th February 2007
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Any idea why some cars show this vapour and some don't? I was thinking head gasket in the back of my mind?

AussieRules

42 posts

229 months

Tuesday 6th February 2007
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It really is nothing to worry about.
As Ringram says you cannot have a car without it and is there all the time, just lower ambient temps etc make it more apparent.
A bloody great 6.0 ltr V8 will make more "steam" than a smaller engined car and it also depends on exhaust tip angles, wind directions and car shapes (at the back end) as to how apparent it becomes.
Saying all that my old Scoob used to make so much you could not see the cars behind when sitting at traffic lights

LuS1fer

43,152 posts

267 months

Tuesday 6th February 2007
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My Mustang does it too - probably a corollary of the shape of the rear end. I'm sure I've read that every gallon of petrol produces a gallon of water.

featherfoot

204 posts

248 months

Tuesday 6th February 2007
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LuS1fer said:
I'm sure I've read that every gallon of petrol produces a gallon of water.


So why so much desert in the Middle East then???tank

LuS1fer

43,152 posts

267 months

Tuesday 6th February 2007
quotequote all
featherfoot said:
LuS1fer said:
I'm sure I've read that every gallon of petrol produces a gallon of water.


So why so much desert in the Middle East then???tank


Because it evaporates, forms a cloud, travels west and p*sses down on Wales.

ringram

14,701 posts

270 months

Tuesday 6th February 2007
quotequote all
LuS1fer said:
I'm sure I've read that every gallon of petrol produces a gallon of water.


That sounds about right as petrol is c5h7 or whatever, all the H becomes H2O, there is nothing else that combines with the H, basic oxidation reaction etc. With some NOx thrown in from the N content of the intake air.