Water from exhaust - Scorpio
Hello all

My brother recently bought a Rover 416 Si N reg with 37,000 genuine miles on it.

The problem which has me stumped is that water and white smoke (steam?)seems to come from the exhaust even when the car is fully warmed up. The temp gauge always reads normal.

This car stood for about 3-4 months before he bought it so I intially thought damp has gotten into the exhaust and it would burn itself out, however this is not the case.

Next I thought of the head gasket, but the car has used no water and does not need to be topped up !

Where is this water coming from ? any help would be nice.

Water from exhaust - volvoman
Hi Scorpio are you sure it's not just condensation from inside the exhaust ? Have you compared with other
416's ? How long has the car been warmed up for ? My old Rover 820 used to create excessive amounts of steam and I was told that was the cause and it's made worse by lots of shortish journeys which don't allow the system to dry out properly. The reason my back box rotted so quickly I guess! HTH
Water from exhaust - Scorpio
Even when the car has been running on the motorway for about 30 mins when you stop and look there is still visible white smoke coming from the exhaust.

Sometimes on short journeys to my house (about 3 miles) you can actually see water dripping fom the tailpipe and it leaves a patch on my drive :(

The back box and pipe seem very rusty to me and the little crome pipe trim thing actually fills with water that steams away for about 5 mins after the car has stopped.

This much water has to be coming from somewhere !
Water from exhaust - Toad, of Toad Hall.
Scorpio don't worry.

My 416 steams a lot (even after 2 hours) and the 414 with a completely different engine did too.

Watch any 2/4 series rover in a traffic queue and you will see clouds of white steam.

You should be glad it's clearing this moisture out!
These are my own opinions, and not necessarily those of all Toads.
Water from exhaust - volvoman
Scorpio - Can't say I can remember how long mine took to dry out but it used to drip from the tailpipe a hell of a lot too ! I'm far from an expert but if the cooling system isn't losing water I can't think of anywhere else this can be coming from.
Water from exhaust - jud
Try drilling a small hole in the back box, any collected water will be drained, i did this to a primera i had. Short journeys allows a build up of condensation, 30 mins on the motorway really isn't long enough to remove any build up.
Water from exhaust - Scorpio
Thanks to you all for the advice, I will tell him not to worry.
Water from exhaust - Cliff Pope
Isn't water one of the combustion products of petrol and air?
I've noticed that lots of cars do this steaming now, and I had put it down to the more efficient combustion of modern engines.
Water from exhaust - John S

Exactly. Petrol is a hydrocarbon fuel, containing hydrogen and carbon molecules. Buring hydrogen in air produces H2O, water. The carbon (fully combusted) produces C02, carbon dioxide. If the exhaust gas is reasonably cool at the back ened of the exhaust, the water vapour will condense and be easily visible.


John S
Water from exhaust - Ste
Not forgetting that the cat will convert a lot of it to water, too
Water from exhaust - blank
This sounds a good way of:
1 - letting water out of the silencer
2 - failing the MOT test for a hole in the silencer (if the tester notices it, of course)
Water from exhaust - eMBe {P}
Andy S - my friend replaced his Cavalier rear-box because it had a hole in it. Only then did he find out that there was a hole in exactly the same spot in the new box. It is there to allow condensed water to drip out.

Scorpio - water in the exhaust is normal. You will see it as "steam" or more accurately as "vapour" if the exhaust is hot enough to allow the water to pass through as a gas. This phenomenon is common in cars running with very-hot cat.conv. temperatures. If the exhaust tail pipe is cold enough, the vapour will condense and you will see drops of water falling out. Just watch the exhaust of other cars in front of you for confirmation.

** HJ Backroomers - ADD your photo albums at:
Water from exhaust - Dynamic Dave
Andy S - my friend replaced his Cavalier rear-box because it
had a hole in it. Only then did he find out
that there was a hole in exactly the same spot in
the new box. It is there to allow condensed water to
drip out.

Curious? None of my old Cavalier exhausts had holes in (apart from in the proper places), not the original systems nor the cheapy replacements fitted afterwards. Having had 3 Cavaliers and replaced the exhausts on each of them at least twice, I find it hard to believe your friends had drain holes in. This hole you're refering to would have to be reinforced anyway otherwise it would rot out into a larger hole in no time.
Water from exhaust - eMBe {P}
DD - the Cavalier in question is a 92K 1.6L, a carb non-cat model. All I can say is this. I have seen the car this evening and the old and new box (old box is awaitng disposal at the tip). There is a definite drain hole at the fore-end of the rear box. The diameter is about 4mm. On the old box (Kwik-fit supplied) the hole is a bit larger and was beginning to blow - possibly because of failure/blockage of internal baffles in the box blocking exhaust gas flow. So whether this is a co-incidence that both the old and new boxes have tiny holes in the same place or whether it is a common fault in the two boxes made by different suppliers, I do not know.

** HJ Backroomers - ADD your photo albums at:
Water from exhaust - Rob E
No need to worry, this seems to be a harmless trait of Rover 2/400's, made more prevalent in colder weather.

I learnt to drive in a Rover 414, and even when the car had been out on lessons all day it would still happily steam away (noticeable especailly when doing three point turns). I

Rob E

Water from exhaust - KB.
Not much of any use to add except to say that I'd thought the same thing the other day re. my 1600 Maestro. Loads of water and steam, even when warm(ish). Did check the water levels and looked for signs of blown H/Gasket and just guessed that it was the cold weather having something to do with it. Did read recently about an exhaust manufacturer providing drain holes for drainage and obviously this wouldn't cause MOT problems otherwise they wouldn't be doing it.

Water from exhaust - nick
I used to put a small hole in the back box of Rover p6s as they ate them on shortish runs. When I did the first one about a half pint of water came out. It never failed an MOT. If you were worried a splodge of gungum before the MOT and remove it after would do the trick.
Water from exhaust - Cliff Pope
I see the logic of the small drain hole in the silencer, but doesn't it cause more exhaust noise?
Sometimes when I have suspected that my exhaust pipe is beginning to blow close inspection often reveals the cause as a tiny, pin-prick hole somewhere in the system. A small hole seems to make a noise out of all proportion to its size.
What is the difference between an intentional hole and and accidental one?
Water from exhaust - nick
I can't speak for other cars but the tiny hole I put in the back box of a p6 made no difference to the noise. Mind you, it was the last box on a 3 box system,
Water from exhaust - Richard_H
Thanks for all the help, I have since looked at some 400s in traffic and they all steam like mad. As you say, this is an unusual trait of this model, strange.

For the money though, this seems like a great car to me and I intend to get one when my current banger expires. What should I look out for if anything ? Some of my friends have doubts about the engine type in these models saying they are prone to failures etc. Is this true ?


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