Hi there,

My 2014 2.0 TDI Octavia sprang a coolant leak the other day. Traced the fault to this coolant pipe which was badly corroded and leaking. Part number is 04L121065AJ.

It runs up the timing belt side of the engine and then locates into the rear of the block via one T30 bolt. Access is horrible because it's sandwiched between the block and what I think might be the catalytic converter, so it took quite a bit of time to get the bolt out. When I finally did get the bolt out my celebrations were cut short because there isn't physically enough room to pull the coolant pipe flange out of the block before it hits the cat. 

Has anyone replaced this pipe before, and if so, what do I have to do here? Removing the cat doesn't look simple, but I suspect it's going to be necessary. Any tips or guidance would be much appreciated!

5 hours ago, JohnMcC123 said:

Hi there,

My 2014 2.0 TDI Octavia sprang a coolant leak the other day. Traced the fault to this coolant pipe which was badly corroded and leaking. Part number is 04L121065AJ.

It runs up the timing belt side of the engine and then locates into the rear of the block via one T30 bolt. Access is horrible because it's sandwiched between the block and what I think might be the catalytic converter, so it took quite a bit of time to get the bolt out. When I finally did get the bolt out my celebrations were cut short because there isn't physically enough room to pull the coolant pipe flange out of the block before it hits the cat. 

Has anyone replaced this pipe before, and if so, what do I have to do here? Removing the cat doesn't look simple, but I suspect it's going to be necessary. Any tips or guidance would be much appreciated!

No experience but sounds like you will need to manipulate the exhaust or downpipe. What is your engine code, 3 or 4 characters at start of engine number,  the vw service manual may provide a recommemded sequence... 

Unsure as to the engine number, I'll have to check tomorrow now.

I found a workshop manual via this link - https://www.hypermiler.co.uk/skoda/skoda-octavia-mk-iii-2013-workshop-service-maintenance-repair-manuals-downloads-inc-vrs-free - which has proved quite useful. Looks like the procedure is to drop the exhaust off then you can move the cat back far enough to access the pipe. Almost sounds easy when you say it like that 😆

18 hours ago, JohnMcC123 said:

Unsure as to the engine number, I'll have to check tomorrow now.

I found a workshop manual via this link - https://www.hypermiler.co.uk/skoda/skoda-octavia-mk-iii-2013-workshop-service-maintenance-repair-manuals-downloads-inc-vrs-free - which has proved quite useful. Looks like the procedure is to drop the exhaust off then you can move the cat back far enough to access the pipe. Almost sounds easy when you say it like that 😆

Yeah until you're doing it one handed, alone,  on the drive,  on your back and the bolts are all rusted tight. Good luck though. Hoping for an easy ride!! 

On 14/08/2024 at 15:36, JohnMcC123 said:

Hi there,

My 2014 2.0 TDI Octavia sprang a coolant leak the other day. Traced the fault to this coolant pipe which was badly corroded and leaking. Part number is 04L121065AJ.

It runs up the timing belt side of the engine and then locates into the rear of the block via one T30 bolt. Access is horrible because it's sandwiched between the block and what I think might be the catalytic converter, so it took quite a bit of time to get the bolt out. When I finally did get the bolt out my celebrations were cut short because there isn't physically enough room to pull the coolant pipe flange out of the block before it hits the cat. 

Has anyone replaced this pipe before, and if so, what do I have to do here? Removing the cat doesn't look simple, but I suspect it's going to be necessary. Any tips or guidance would be much appreciated!

sorry to raise an old thread! Did you have any luck with this in the end? just done a service on mine, and noted a bit of coolant loss over the last few weeks, and guess what.... its the pipe next to the one you replaced! coolant pipe at the rear, its referred to in the manual i have. looks an easy enough replace, but the coolant pipe you had trouble with is also looking past its best now so recon that'll need doing soon. looking for replacement pipes as i speak, suspect a call to the dealers tomorrow will be in order..

Yes, I got it replaced. You have to strip quite a bit of stuff, but once you do that the access isn't too bad. It just requires a bit of work unfortunately. I just worked off the workshop manual in the link above. Any specific questions though, just ask!

15 hours ago, JohnMcC123 said:

Yes, I got it replaced. You have to strip quite a bit of stuff, but once you do that the access isn't too bad. It just requires a bit of work unfortunately. I just worked off the workshop manual in the link above. Any specific questions though, just ask!

Cheers John, much appreciated! Ill put it in the list of things to do! Octy is getting to that age now it seems!

Cheers again 👍👍

Sorry for raising an old friend again... sounds like a few of us unfortunate folk have had the same pipe go. Ive managed to get to the part where i need to push back the exhaust coolant.

Im having an absolutely nightmare bringing out this pipe, the two pipes are welded to each other so have no flex and i cannot see how the hell they come out.. around the area in red is very very tight - the pipe is completely loose but no idea if i should be pulling it directly up and out (orange), pushing it backwards (yellow) or forward (blue).

Did yours come out ok? i cant for the life of me see what else i should remove.. I'm wonderin gi i remove the purple part if it comes out a bit easier. but if that needs removing i dont get why it tells me to disconnect the clamp from it.
Any help greatly appreciated.



I need to remove this pipe to get to two bolts here (1 & 2).

Just updating so others know - i managed to sort it by removing 3 screws that were holding the gear shift cables - it gives just enough room to get them out.