[anjan_c2007]

The best way to let the silencer last longer is to pour some 200ml or so of used engine oil to reach the muffler through a long plastic pipe with a funnel top, inserted through the tail end. I have been using this method for the last 8 years or so and have got very good results. The rusting is saved and the silencers last very long. The oil has to be replenished every few thousand kms as it evaporates.No doubt some extra white smoke is emitted but thats quite negligible.
A tattered silencer consumes more fuel other than spoiling the engine
and the fuel system too.During the combustion cycle it may also suck in air that is lead back to the fuel system.
Welded silencers don't last more than a few months. Its better to replace the old one for a new one in case the old one develops exhaust leaks.

[hrag]

I thought exhaust (silencer) assemblies (on petrol 4-wheelers) lasted longer the more one drove. Particularly on everyday drives. Might be wrong, though.

[Rehaan]

Originally Posted by hrag

I thought exhaust (silencer) assemblies (on petrol 4-wheelers) lasted longer the more one drove. Particularly on everyday drives. Might be wrong, though.

Well, the reasoning behind that is that they heat up and get all all the moisture out, hence less rusting.

However, that applies only when you go for longer drives which gives enough time for this to happen. Frequent short drives will not have the same effect.

cya
R

[Narencar]

One of my uncle who has a driving experience of 10-15 years is always saying that when you stop the engine to park the car for 10-15 hours then accelerate the engine at some high rpm at idle mode so the moisture deposited in silencer will be exhausted and the hence no rusting at all.
and its leads to longer life of silencer....

[mithun]

The best way to let the silencer last longer is to pour some 200ml or so of used engine oil to reach the muffler through a long plastic pipe with a funnel top, inserted through the tail end.

Does this trick applies to both petrol & diesel vehicles ?

Originally Posted by Narencar

One of my uncle who has a driving experience of 10-15 years is always saying that when you stop the engine to park the car for 10-15 hours then accelerate the engine at some high rpm at idle mode so the moisture deposited in silencer will be exhausted and the hence no rusting at all.
and its leads to longer life of silencer....

I think this is pure stupidity since if simply revving the engine at idle removes the moisture then the normal riding should have also removed the moisture !

[supremeBaleno]

Originally Posted by anjan_c2007

The best way to let the silencer last longer is to pour some 200ml or so of used engine oil to reach the muffler through a long plastic pipe with a funnel top, inserted through the tail end. I have been using this method for the last 8 years or so and have got very good results.

Don't know if this is the 'best' way, but I used to do this for my bike silencer for the first few years after buying it in '95. Since I was doing close to 100kms a day, there was really no need for this. But had heard about it from someone, felt it logical and practised it.

Originally Posted by anjan_c2007

Welded silencers don't last more than a few months. Its better to replace the old one for a new one in case the old one develops exhaust leaks.

Have to disagree with this one. Welded silencers do last. And not just months, but years. We used to have this silencer-rust problem with our M800 at Kerala - due to being sparsely used and also due to the humidity + round-the-year rains at Kerala. It was a '85 M800 and the asking price for a new silencer was pretty prohibitive (2K or so then) and so I would unbolt the silencer and get it welded. And yes, it did last.

[alpha1]

Originally Posted by anjan_c2007

The best way to let the silencer last longer is to pour some 200ml or so of used engine oil to reach the muffler through a long plastic pipe with a funnel top, inserted through the tail end. I have been using this method for the last 8 years or so and have got very good results. The rusting is saved and the silencers last very long. The oil has to be replenished every few thousand kms as it evaporates.No doubt some extra white smoke is emitted but thats quite negligible.
A tattered silencer consumes more fuel other than spoiling the engine
and the fuel system too.During the combustion cycle it may also suck in air that is lead back to the fuel system.
Welded silencers don't last more than a few months. Its better to replace the old one for a new one in case the old one develops exhaust leaks.

Had it been about coating the exteriors of the silencer with oil - I could've agreed.
HOWEVER, when we run our vehicles, there is anyways a large unburnt hydrocarbon content that gets deposited as a thin film in the exhaust system.

That is sufficient to prevent rusting from inside.

[Ravveendrra]

I have heard of this. It was popular with some mechanics and owners. My doubt is this:

Often there is back pressure in the exhaust system, when this happens if the oil in the muffler gets sucked into the catalytic converter or carbon collecter, will it harm these components?

On a more minor note:

The oil will trap some of the carbon emissions, will it then become some kind of a sludge or gunk? How does one clean this? I remember de-carbonising the old 2stroke silencers used to be a pain.

Cheers,

[filcord]

Please do not pour any oil. This is nonsense. You will spoil the catalytic converter, which costs in thousands.
The main cause of early rust in exhaust pipes is when you run an engine for short drives, that results in water vapour condensation in pipes that are not hot enough. Moral of the story - use the car as far as possible when you will be running it at least 30 minutes.
Want to save the earth (and yourself)? Walk if you possibly can for those short trips.

[getsurya]

Friends,
Is this rusting of silencers specific to
1. Cars which are run for many years?
2. Cars which are driven in coastal areas or areas of high humidity?
3. Cars which are driven or exposed to water logged stretches regularly?

As myself owning cars for last 12 years(7 years for two of them) i never faced this issue. Also I remember, My grandads Willy's silencer would get rusted and has to go for replacement. But it was driven regularly to our Farm house with no proper roads and through slush, and parked outside generally!!

[vikram_d]

Originally Posted by mithun

I think this is pure stupidity since if simply revving the engine at idle removes the moisture then the normal riding should have also removed the moisture !

It is not stupidity. The velocity of gases is higher when you rev the engine than at idle.

Originally Posted by supremeBaleno

Have to disagree with this one. Welded silencers do last. And not just months, but years.

Perfectly said. Depends on the welding quality though.

Originally Posted by alpha1

Had it been about coating the exteriors of the silencer with oil - I could've agreed.
HOWEVER, when we run our vehicles, there is anyways a large unburnt hydrocarbon content that gets deposited as a thin film in the exhaust system.

That is sufficient to prevent rusting from inside.

I agree with this. And also in a vast majority of cases the rust starts from the outside and not from the inside.

Originally Posted by filcord

Please do not pour any oil. This is nonsense. You will spoil the catalytic converter, which costs in thousands.
The main cause of early rust in exhaust pipes is when you run an engine for short drives, that results in water vapour condensation in pipes that are not hot enough. Moral of the story - use the car as far as possible when you will be running it at least 30 minutes.
Want to save the earth (and yourself)? Walk if you possibly can for those short trips.

I agree with this completely.

[rranjith_kum]

I already have a reconditioned silencer in my Santro this was done during the last service.
The cost of a new silencer is sure a hole in the wallet and normally petrol engines do emit a lot of moisture

[anjan_c2007]

Originally Posted by Rehaan

Well, the reasoning behind that is that they heat up and get all all the moisture out, hence less rusting.

However, that applies only when you go for longer drives which gives enough time for this to happen. Frequent short drives will not have the same effect.

cya
R

Thats true. When we move our car within the city limits, for shorter runs daily, within the city limits and run the car at low speeds in bumper to bumper traffic, the engine releases a certain amount of moisture that goes to the silencer and does not evaporate.Thats due to the fact that a temperature of 100 degrees Celsius is not achieved, which is necessary for turning the accumulated moisture/water into steam and evaporate. Thats why one will notice droplets of water flowing out from the silencer pipe, when a car just commences its drive.
If the daily runs are longer (more than 50 kms or so) causing the silencer to heat and the moisture to in turn evaporate, it solves the problem to a great extent. But due to shorter runs the moisture accumulates and later causes corrosion of the silencer from within.No amount of outside coating can be of any help in such cases.
And as regards welded silencers one can go ahead with it if the runs are shorter and restricted to the city at low speeds. The moment the silencer heats up during long drives, all the welding will of any kind whatsoever will fail.

[sudipta]

I have a 3 inch long and 2 inch wide whole in my Ikon exhaust pipe near the right rear wheel. The service center quoted a charge of around 10k for replacement. I would like to know if any one can guide me to a place where they can mend it at Hyderabad.

[alpha1]

Originally Posted by anjan_c2007

Thats true. When we move our car within the city limits, for shorter runs daily, within the city limits and run the car at low speeds in bumper to bumper traffic, the engine releases a certain amount of moisture that goes to the silencer and does not evaporate.Thats due to the fact that a temperature of 100 degrees Celsius is not achieved, which is necessary for turning the accumulated moisture/water into steam and evaporate. Thats why one will notice droplets of water flowing out from the silencer pipe, when a car just commences its drive.
If the daily runs are longer (more than 50 kms or so) causing the silencer to heat and the moisture to in turn evaporate, it solves the problem to a great extent. But due to shorter runs the moisture accumulates and later causes corrosion of the silencer from within.No amount of outside coating can be of any help in such cases.
And as regards welded silencers one can go ahead with it if the runs are shorter and restricted to the city at low speeds. The moment the silencer heats up during long drives, all the welding will of any kind whatsoever will fail.

Not quite right.
Water doesnt need to attain 100 deg Celcius to evaporate.
100 deg celcius is BOILING POINT.
But water vapours are formed at each and every real life temperature that you encounter.

Do you need to heat your wet clothes till 100 deg celcius to remove the moisture/water?

In anycase, as I mentioned earlier, normal running of engine ensures that your exhaust circuit interiors are always coated with an unburnt/partially burnt oil slick.
Don't believe me? Open up ANY car exhaust.

It is this slick that prevents any rusting from inside.


Not the pouring of engine oil into the exhaust circuit.