Hi all,

I’ve tracked down a coolant leak on my 2016 Octavia Mk3 (reg FT15 AXW, engine code CRMB 2.0 TDI 150). The two metal coolant hard pipes that run down by the sump are heavily corroded and leaking.

I think the families are:

• 5Q0 121 070 xx (main hard return pipe)

• 04L 121 065 xx (companion feed pipe)

…but I’m struggling to work out the correct suffix letters for my car. Autodoc and other sites list loads of variants (AF, AJ, BR, CR etc.) and I don’t want to order the wrong ones.

Can anyone help me understand what i need and what suffix to use? I'm also worried about things i should do whilst im there such as O-rings, and clips and if its worth doing things like waterpump whilst im there.. Im a DIY enthusiast hard up for cash so going to teach myself..
.
VIN: TMBKJ7NE0G0028314 REG: FT15 AXW (if you’re happy to use it for the lookup).

Model: Škoda Octavia Mk3 (Typ 5E)

1. Model Year: 2016

2. Engine: 2.0 TDI (EA288)

3. Engine Code: CRMB (150 PS / 110 kW)

4. Fuel: Diesel

5. Body Style: Estate (5E5)
   

Any advice would be hugely appreciated — I just want to get all the right bits together in one go so I can sort the leak properly and get back on the road.

Thanks in advance!

I'm going to need more help. It's not clear where on the engine those are, the picture is a bit too close in for spatial context.

Do those two appear recognisably (to you) in this image? The title of this page in ETKA is

Coolant cooling system D - 26.05.2014>> 2.0 Ltr. rear Diesel eng.+ PR:DN1,DN4, DN6,DK7+

There are at least two other diagrams though, titled right and left side.

The part numbers you quote in your post, without suffices are items 12 with suffix AF, and item 7 with suffix BH, superseded by 04L 121 065 CR , for your VIN.

Those two don't appear to be adjacent in the exploded view, so I'm confused about why you think those two base numbers are the ones in your pic?

Massive thanks for taking your time to have a look.

I will help to try and narrow it down.. Take the part numbers i provided with a pinch of salt, i got them after several hours of googling and research and thought it was:

Pipe 1 – Main Coolant Return / Transfer Pipe: OEM : 5Q0 121 070
Pipe 2 – Coolant Feed / Companion Pipe: OEM : 04L 121 065

BUT I COULD BE COMPLETELY Wrong.....

The area that the pipes are located are in this area. They are in the mid height range and then both go into rubber hoses.



I will go and trace where they run now to see if i can see what they are feeding into.. Trying to get a picture from underneath is a nightmare, This one might help with a clue on positioning as you can see its right next to the belt.

Ok ... i got a video and some better pictures ➕

The wet is from gravity.. The actual leak and rusty pipe is coming from the circled spot above which i think is going in, and out of the oil cooler.

Here is the video.

Looking at the diagram, it does look like its 7 and 12? Not sure on your thoughts? If it is would you be so kind to provide part numbers for:

8, 9, 18, 19, 20, 21, 22, 23, 62, 63 - Id rather just replace everything in that area with new as im guessing some of the clips etc are going to be shot looking at the state of the rust.

Not sure how to edit but i think its part 7 and 20, not 7 and 12?

Item 20 is 04L121065AJ (RRP £44.90 + VAT) as shown here, along with part numbers for a lot of the other bits you mention. Car Parts Catalog - LLLParts

It appears to be this bit:

Its o-ring, where it connects to the engine block is correctly given as item 21 on that page (over £6 at dealers!)

That LLLparts page isn't up to date enough to feature the suffix -CR part for item 7 (also @ RRP £44.90 + VAT currently), as mentioned in my post yesterday.

Note: although very conveniently selling genuine parts at good prices, LLL can be rather slow to deliver. Think weeks rather than days. Dealer ought to be quicker but will obviously charge full RRP.

I would speculate that you will find it awkward (and expensive!) enough to replace these two, along with directly attached hardware, to want to do any other replacements.

Thank you so much - I very much appreciate that time out of your day to help a stranger out. A huge help!