Coolant Pipes with engine in?

[RSrich81]

Hi all

I hear the classic rusty coolant pipes can be replaced with the engine in but can be tricky.

Does anyone have any pics and tips for doing it?

I hear some people just cut the bad bits out to make it easier, I would prefer to do the whole pipe if I can

Cheers
Rich

[Jim Haseltine]

See my comments here viewtopic.php?f=47&t=126612
Yes, they can be replaced with the engine in place.
No, the job isn't tricky - it's phenomenally difficult and tricky.
And unless you're really lucky, have very thin forearms and are double-jointed you will injure yourself.
6 years down the line even without a sun tan the scars are still visible on the inside of my left forearm.

The worst/most difficult part of the job is that the far end of the long pipe joins to a flexi pipe in the centre of the car, with the only access to the joint and the hose clip being via a hole in the front face of the engine bulkhead, circled here in a pic I've stolen from elsewhere on the 'net.


Since then I've pulled my engine twice (or is it three times?) and to be honest I'd only replace those pipes another time with the engine in place if I really had to.

[RSrich81]

Oh that doesn’t think like too much fun, got a few bits to do so looking like it’s going to be easier to pull the engine out.

Cheers

[Ed Chappell]

I saw quite a few posts on this topic before tackling this job to replace the full pipes with the engine in. Jim H is right in his assessment!
For those who want to read a guide before they start just PM me and I will send a write up of how we did it in pdf format.
Important pictures of where the elusive 10mm bolt head and metal to rubber joint are situated are included because you can't easily see them on the car when you start out.

[welwynnick]

I think everyone on this forum would like a guide to this job. Many other people have already posted their experiences of other jobs for the benefit of others. It's a community thing.

[James Tanner]

See attached pdf for pics

The known problem of the coolant pipes in the wheel arch corroding has come to visit my RS6. I went from no leak when I left the house to arriving home and a jet of coolant coming out the pipe and the joy of watching as my Audi widdled its coolant all over my garage floor.
Removing the wheel arch liner and guard for the power steering arm this is what I found:


The shorter of the 2 pipes (marked as 22 in the drawings) is changeable from the wheel arch. The main issue is that to change the longer one of the two (marked as 49 in the drawings) you need to remove the engine as it runs behind the block to connections to the heater matrix in the car and the return from the engine. This is quoted as an engine out job (so £4k labour before you even start). This is further compounded with circa £500 for the two pipes.

My solution was to replace the pipes with silicone pipes and join the pipes together, as this will eliminate any future issues with corrosion.
First off was the removal of the pipes.
For pipe 22 this is simple as you can reach the other end, for pipe 49 this is more difficult as it requires cutting the long pipe with a pipe cutter on a good section of pipe.

The longer pipe was so rotten that it snapped during removal

It is worth noting at this point that the 22 pipe is fixed in place by being bolted to the 49 pipe, it is the 49 pipe that is attached to the stud on the car. So if you wanted to replace the 22 one with a metal pipe and the long with a silicone you would need to fashion a way of holding the pipe.
To make the corner to the tank I kept the s bend pipes – this is key as the metal pipes are 16mm diameter and the pipes on the header tank is 19mm so the s-bend pipes also act as reducers.
I purchased 2m of Si 16mm ID radiator hose (£22) and 10 SS heavy duty pipe Mikalor clamps (£22) and two 16mm straight pipe joiners (£4).The straight pipe joiners are not ideal as it will reduce the internal diameter of the pipe and therefore reduce flow – if this leads to overheating I will look to replace the plastic ones with metal joiners which have a bigger ID
The top pipe, which bends round to the right (replacing 22) needs to be long enough to go past the guard around the power steering arm and to get the wheel arch liner to fit I rotated the clamps on the top pipe to tuck into the space better


To retain and protect the pipes from gravel and dirt from the road, I manufactured a guard out of galvanised steel with a hole in the centre of it to cove the area worst affected by rust and fitted it to the stud that previously held the hard pipes


I rolled the near side edge of the guard/retainer as the new pipes rest on it and I needed to avoid any sharp edges
I then re-filled the system and fitted the wheel arch liner

[Spindle]

See attached pdf for pics

The known problem of the coolant pipes in the wheel arch corroding has come to visit my RS6. I went from no leak when I left the house to arriving home and a jet of coolant coming out the pipe and the joy of watching as my Audi widdled its coolant all over my garage floor.
Removing the wheel arch liner and guard for the power steering arm this is what I found:


The shorter of the 2 pipes (marked as 22 in the drawings) is changeable from the wheel arch. The main issue is that to change the longer one of the two (marked as 49 in the drawings) you need to remove the engine as it runs behind the block to connections to the heater matrix in the car and the return from the engine. This is quoted as an engine out job (so £4k labour before you even start). This is further compounded with circa £500 for the two pipes.

My solution was to replace the pipes with silicone pipes and join the pipes together, as this will eliminate any future issues with corrosion.
First off was the removal of the pipes.
For pipe 22 this is simple as you can reach the other end, for pipe 49 this is more difficult as it requires cutting the long pipe with a pipe cutter on a good section of pipe.

The longer pipe was so rotten that it snapped during removal

It is worth noting at this point that the 22 pipe is fixed in place by being bolted to the 49 pipe, it is the 49 pipe that is attached to the stud on the car. So if you wanted to replace the 22 one with a metal pipe and the long with a silicone you would need to fashion a way of holding the pipe.
To make the corner to the tank I kept the s bend pipes – this is key as the metal pipes are 16mm diameter and the pipes on the header tank is 19mm so the s-bend pipes also act as reducers.
I purchased 2m of Si 16mm ID radiator hose (£22) and 10 SS heavy duty pipe Mikalor clamps (£22) and two 16mm straight pipe joiners (£4).The straight pipe joiners are not ideal as it will reduce the internal diameter of the pipe and therefore reduce flow – if this leads to overheating I will look to replace the plastic ones with metal joiners which have a bigger ID
The top pipe, which bends round to the right (replacing 22) needs to be long enough to go past the guard around the power steering arm and to get the wheel arch liner to fit I rotated the clamps on the top pipe to tuck into the space better


To retain and protect the pipes from gravel and dirt from the road, I manufactured a guard out of galvanised steel with a hole in the centre of it to cove the area worst affected by rust and fitted it to the stud that previously held the hard pipes


I rolled the near side edge of the guard/retainer as the new pipes rest on it and I needed to avoid any sharp edges
I then re-filled the system and fitted the wheel arch liner

Thanks for sharing this, I've saved it as I am sure I will end up needing to do this job at some point!