Lots of Steam from cold engine start up each chilly morning.

[Abott10]

MY MG6 engined 1.8T ZT-T see masses of steam on cold engine start up and clouds of it exiting the exhaust for the first couple of miles in this chilly weather.

So I drilled a small hole in the front and rear of the lowest part of the rear silencer. Immediately lots of water passed around the drill bit all over my hands and onto the floor. I would say at least a small cup full of water drained out.

The attached images show what was involved.

[Mgaz]

Is this why some silencers rot so bad?

I've seen an R45 with half the silencer in rusty bits with big holls in it!. Least its fair to say it wouldn't be holding any more water in that state. ;)

[stux99]

So is that why my GS has drain holes either end of the box?

[RoverP480]

Every gallon of fuel burnt produces a gallon of water . Was the silencer an original or aftermarket one. I know we ( Rover ) used to put a small pitot type tube inside silencers to suck out any water from the bottom when the engine running. Short journeys are the main problem , as the exhaust doesn't get hot enough to evaporate the condensate off as vapour. We had a van in the department that wasn't used but frequently started for a few mins , to move around from one part of the workshop to another , exhaust lasted only 4 months

[T-Cut]

A small cup full of petrol generates around the same volume of water when combusted. So every gallon of juice you burn puts around 1700 gallons of water vapour out the exhaust pipe.

TC

[bl52krz]

Not in my diesel it don’t rot away. It’s original. 16 years old this year. Another advantage of diesel.

[T-Cut]

Not in my diesel it don’t rot away. It’s original. 16 years old this year. Another advantage of diesel.

Diesels make the same amount of water, but it's oily.

TC

[minimutly]

Every gallon of fuel burnt produces a gallon of water .

Really? You would have thought this would be the breakthrough the Arabs have been looking for regarding their water shortage....

[Mgaz]

Is this hole worth drilling in my silencer ?

You say the water came out with a hole at the front end rather than the rear?


I've noticed there seems to be a tiny pin hole in the one end of the MG F silencer as well. And if you put your finger by it, you feel water coming out of it on tick over.


One point about the ZT 190 exhaust, didn't I read back in the day that they had a valve inside them that opened up when giving it some welly ? To give the 190 a more sporty engine note ?

If that's true, wouldn't want to drill into something that damaged it some how?

[Comfortably Numb]

The K series, in all formats, deserved the reputation for blowing its ORIGINAL hg, it was a rubbish gasket, and far too many MGR motors suffered failure before 50,000 miles.
However, properly refitted with the improved gasket, proper maintenance of the cooling system, and driving sensibly during warm-up, the engines are generally very reliable, and need not worry their owners that every trip could be the last!
The MG breaker specialists at Peterborough who supplied my second hand replacement VVC engine assured me they always change the HG before an engine leaves them, whether it has failed or not, because if it hasn't failed then, they don't want angry customers complaining that it just did!

[roverbarmy]

I have done exactly the same thing. Make sure that you spray some primer and gloss into the hole and let it trickle back out to seal the metal and protect it. A small self tapping bolt with a bit of gun gum around the thread at MOT time is recommended to avoid the "advisory" re leak of gases! ;)

[Mgaz]

The pin hole i mentioned is factory i think . It's almost a brand new exhaust (well hardly used anyway )

My dad fitted it to his MGF not long before he passed away in September 2016.

I don't think its a genuine rover part. Im not near by the car atm so from memory I think the hole is on one of the flat vertical ends of it.

Can't be sure without looking.

Its so small I wouldn't have even known it was there if I hadn't have heard it 'spitting' the water out. If you put your ear near it you can hear the air and water coming out.

[roverbarmy]

I need a new rear box on my recent 44,000 mile 2 litre V6 but it's on the original exhaust, which appears to be a one piece unit (No doubt the original factory one?). I haven't had time to check where the join is but it definitely isn't under the boot where my 1.8 is. :shrug:The rear silencers that I have looked at are all joined there.
Mike

[bl52krz]

Gasoline has approx 7 lbs of water per gallon. When burnt, it produces1.52 gallon of water.Propane produces 0.81 gallons, and diesel and kerosene produce 1.05 gallons. Ultra low sulphur diesel (ulsd) two tenths of 1% dissolved water which works out to 8 ozs in 30 gallon of water.

[T-Cut]

Diesel combustion produces about the same amount of water as petrol, apart from any dissolved moisture in the feed. Drilling a hole will allow condensate to drain away from the silencer box, but you can't stop the initial steaming, which is from the water vapour in the exhaust being cooled. When the exhaust system gets hot, there's no internal cooling, so no steam and no condensate. But the water's still there in the exhaust gases.

TC

[Sheraton]

:cool: I just drilled my Aftermarket Backbox today - we'll see if there's a difference.

I actually thought for a moment yesterday something more serious may have happened :eek: - but it does appear to be just steam from water accumulating in the exhaust.

one difference i notice straight away - even such a small hole affects the Exhaust note......maybe even sounds a bit better :D :shrug:


Paul.