Citroen GS Exhaust

[EvanE]

Folks
My newly acquired GS required new preheating exhaust pipe right as the base was rusted through - I purchased this replacement - the old one was a attached at the base - the replacement is a single piece. Would be grateful for some direction as to how it should be fitted before I have the entire car in poeces!

Cheers Evan

 

[andrewj]

Folks
My newly acquired GS required new preheating exhaust pipe right as the base was rusted through - I purchased this replacement - the old one was a attached at the base - the replacement is a single piece. Would be grateful for some direction as to how it should be fitted before I have the entire car in poeces!

Cheers Evan

Hi Evan,

Firstly, the rusted base is a common problem- this comes from starting the car and not running it long enough for the exhaust heat up. End result is condensation sitting in the pipe and slowly rusting it's way through. Solution is to be sure to bring the exhaust up to temperature each time the car is started.

This can be a very frustrating job, so in my experience, it is best to start by removing and cleaning all exhaust tubes from the manifold to the pipe back the muffler the Y section.

Smear each joint with grease. Then work from front to back, jiggling and tighten each joint as you go. I've never had it work first time, so hopefully you have better luck!

Cheers,
Andrew

 

[EvanE]

Andrew
Thank you for your response. I have removed the exhaust with the vertical pipe (preheating) disconnected.
The replaced exhaust is a single unit and I cannot see a way of inserting it other than an engine out or teh fender and lining.
What am I missing
Cheers
See attachment

 

[Steven King]

Vague and erratic memories of both types - i'd wanted to forget GS exhaust systems
- affixed risers certainly would make fitting effectively impossible with all in situ ( if less to leak )
so i'ld be offended enough to cut it off and not bothered about making it work , just blank it ;
while there's arguably a balance pipe effect, deletion seemed common, IIRC.
Even in summer it paid to warm the little darlings up for about as long as another cuppa, but our carbys rarely iced.

 

[Ken W]

If you take out the engine mount bolts from under the front subframe, you can slide the engine sideways to perhaps get that exhaust pipe into place. You may have to lift the engine a bit to get the engine mount bolts back in after you have finished as the mounts do move around and forwards if not restrained when weight is on them.

I've even heard of people using this technique plus lifting a side of the engine to take heads off with the engine in the car although I have never tried this myself.

We have found that you need to use silicon exhaust sealer to get the exhaust sealed enough to pass a safety certificate after the whole exhaust has been disassembled and reassembled.

Cheers, Ken

 

[brian woodcock]

Hi evan, have you checked the Hot Spot under the Carby, most of them have corroded through which is why many are blanked off. The 2cv is similar but the hot spot is cast iron and is no bother .

 

[EvanE]

Vague and erratic memories of both types - i'd wanted to forget GS exhaust systems
- affixed risers certainly would make fitting effectively impossible with all in situ ( if less to leak )
so i'ld be offended enough to cut it off and not bothered about making it work , just blank it ;
while there's arguably a balance pipe effect, deletion seemed common, IIRC.
Even in summer it paid to warm the little darlings up for about as long as another cuppa, but our carbys rarely iced.

Steven
Thank you - good advice - I will have to follow.
Cheers
Evan

 

[EvanE]

Hi evan, have you checked the Hot Spot under the Carby, most of them have corroded through which is why many are blanked off. The 2cv is similar but the hot spot is cast iron and is no bother .

Thanks Brian - am still trying to find a used bit to replace rusted portion - will look out for the corrosion
Evan

 

[EvanE]

Hi evan, have you checked the Hot Spot under the Carby, most of them have corroded through which is why many are blanked off. The 2cv is similar but the hot spot is cast iron and is no bother .

Thanks Brian

 

[EvanE]

Hi evan, have you checked the Hot Spot under the Carby, most of them have corroded through which is why many are blanked off. The 2cv is similar but the hot spot is cast iron and is no bother .

B

Hi Evan,

Firstly, the rusted base is a common problem- this comes from starting the car and not running it long enough for the exhaust heat up. End result is condensation sitting in the pipe and slowly rusting it's way through. Solution is to be sure to bring the exhaust up to temperature each time the car is started.

This can be a very frustrating job, so in my experience, it is best to start by removing and cleaning all exhaust tubes from the manifold to the pipe back the muffler the Y section.

Smear each joint with grease. Then work from front to back, jiggling and tighten each joint as you go. I've never had it work first time, so hopefully you have better luck!

Cheers,
Andrew

Thanks Andrew - will report back.

 

[Steven King]

won't help with the original query, but was it aluminium that corroded?

 

[EvanE]

Thanks Steven for the follow up - it was at the base of the 20mm pipe from the right hand exhaust to the carburettor
Cheers
Evan

 

[andrewj]

Hi Evan,

I'm afraid I'm not much help on the single piece pipe, as I have only ever worked with two piece ones.

How bad is the rust in the old pipe? Is it an option bodge it up with an exhaust bandage for a few years, and wait until you have another reason to lift the engine? Or alternatively, get an exhaust place to cut and put a sleeve on line the original two piece unit?

As the others have alluded to above, if you are going to open up the exhaust, best to fix everything at once so you can forget about it for quite a few years.

Cheers,
Andrew

 

[EvanE]

Hi Evan,

I'm afraid I'm not much help on the single piece pipe, as I have only ever worked with two piece ones.

How bad is the rust in the old pipe? Is it an option bodge it up with an exhaust bandage for a few years, and wait until you have another reason to lift the engine? Or alternatively, get an exhaust place to cut and put a sleeve on line the original two piece unit?

As the others have alluded to above, if you are going to open up the exhaust, best to fix everything at once so you can forget about it for quite a few years.

Cheers,
Andrew

Andrew
I am going to cut and sleeve it - rushed into it without talking to you and others. It will be an engine out if I don't cut and sleeve it
Will be good for many years. The rest of exhaust/manifolds are good.
Many thanks for guidance/support.
Off to Phillip Island to watch histories races this weekend
Cheers - Evan


Evan

 

[andrewj]

Andrew
I am going to cut and sleeve it - rushed into it without talking to you and others. It will be an engine out if I don't cut and sleeve it
Will be good for many years. The rest of exhaust/manifolds are good.
Many thanks for guidance/support.
Off to Phillip Island to watch histories races this weekend
Cheers - Evan


Evan

Hi Evan,

That sounds like a practical way forward. If you don't have tube for the sleeving at hand, let me know and I can post you an old joint (photo below) from my GS graveyard.
.

Cheers,
Andrew

 

[EvanE]

Hi Evan,

That sounds like a practical way forward. If you don't have tube for the sleeving at hand, let me know and I can post you an old joint (photo below) from my GS graveyard.
. View attachment 237923
Cheers,
Andrew

Andrew
Have sleave sorted and have inserted right exhaust - I am now startting to refit - a challenfge - not to be attemted when tired!
Thanks again
Cheers

 

[EvanE]

Andrew
New part did not fit and preheat pipe was too short. Had old preheat pipe professionally repaired and fitted - started from the front and worked back. Am now a professor!
Thanks for the support
Evan

 

[Mitchell]

Any chance of you doing some work on my GS exhaust system Evan?

 

[EvanE]

There is not enough money in the world! !!!

 

[forumnoreason]

you need to be a yogi to work on a GS. It would certainly help.