Just finished replacing the Oil Cooler on my 2013 3.0 TDI CNRB.
I'm posting this in case someone can use what I learned.
The reason I replaced it was because of random coolant loss on cold mornings which lead me to notice oil in valley area of the block below the intake manifold. The oil cooler had been replaced once under warranty so I suspected the seals weren't sealing. I ended up putting Febi cooler on it. I could have probably reused the original cooler but didn't want to spend hours cleaning and scrubbing it and making sure it was absolutely ready to go back on. It was just quicker to put a new cooler on.
Upon disassembly I found quite a few of the T30 Torks bolts to be slightly less torque then the rest of them.
My advise to anyone thinking their cooler is leaking would be to look for obvious signs of leaking and try re-torquing the bolts one by one. It take about 2 hours to get to the oil cooler (removing a few items required to remove the intake). I found for some reason the bolts on the passenger side were less torqued than the right side.
I also noticed the adapter plate between the block and the oil cooler is a raw casting (no machining), so when I checked it for flatness found it to be out of flat by 0.005" on a granite table. I suspect this is part of what causes leaks as the seal is 100% reliant on the gasket which over time will loose it's elasticity and require re-tightening of the bolts. In my case I lapped the surface of the plate on the granite table with 320 grit sand paper until it was nice and flat, cleaned it with detergent and water to get all the oil residue off and then re-assembled it with new gaskets and the new Febi oil cooler.
I also found (perhaps obvious to any technician reading this) that as I torqued the the plate from the inner outward in a star pattern in 3-4 Nm intervals (like torquing a cylinder head). That I'd have to recheck torques at least 3-4 times around the complete pattern. I could walk away for a few minutes and check them again and notice a few needed to be re-torqued. Eventually they were all torqued and several checks around the torque pattern they were all about the same. I used a bending beam torque wrench with the pointer needle instead of a click lock style, so I could see the torque on each fastener.
After about 150 miles of driving it seem to be leak free.
For anyone doing this job in the future I recommend buying a new fuel cross over line (I'm told they aren't reusable, however I reused the one I have), and also replace the plastic Manifold and Thermal valve "while you're in there". I also recommend replacing the three hoses that connect to the manifold, EGR cooler and Thermal valve. It turns out the O-Rings on the Manifold are available from VW, and in fact the Manifold doesn't come with the O-Ring. There are two 90 degree elbow hoses one connecting to the EGR cooler (large bend radii) and another 90 degree elbow on the thermal valve to manifold connection as well as an almost straight piece of hose from the EGR Cooler to the Waterpump.
I will probably have to go back in and replace these in a year or three. I didn't have them on hand and the dealer didn't have any so I reused the old ones. However replacing these hoses later will basically require me to repeat the entire job.
I found the toughest part of this job is cleaning the mess in the engine valley. I used a very cheap bucket type shop vac to extract coolant from the hose on the water pump that connects to the EGR cooler and to vacuum up the oil goop in the valley area of the engine.
There are a lot of nooks and crannies in the valley area that if you want it perfectly clean (as I did) it will take several hours with to clean without getting anything into the openings.
In my case I put paper towels in the openings to catch any debris and vacuumed the debris before removing the paper towel and then inspected very carefully the oil cooler valve spring to make sure nothing got into the oil.
Overall the cleaning process took me about 6 hours with a few breaks. Some of the problem was the paint chipped off and I had to be sure to get all the gritty rust / paint mixture out.
Re-assembly took about 4.5 hours taking my time.
I'll post more details if anyone wants them and pictures and a parts list.
I'm posting this in case someone can use what I learned.
The reason I replaced it was because of random coolant loss on cold mornings which lead me to notice oil in valley area of the block below the intake manifold. The oil cooler had been replaced once under warranty so I suspected the seals weren't sealing. I ended up putting Febi cooler on it. I could have probably reused the original cooler but didn't want to spend hours cleaning and scrubbing it and making sure it was absolutely ready to go back on. It was just quicker to put a new cooler on.
Upon disassembly I found quite a few of the T30 Torks bolts to be slightly less torque then the rest of them.
My advise to anyone thinking their cooler is leaking would be to look for obvious signs of leaking and try re-torquing the bolts one by one. It take about 2 hours to get to the oil cooler (removing a few items required to remove the intake). I found for some reason the bolts on the passenger side were less torqued than the right side.
I also noticed the adapter plate between the block and the oil cooler is a raw casting (no machining), so when I checked it for flatness found it to be out of flat by 0.005" on a granite table. I suspect this is part of what causes leaks as the seal is 100% reliant on the gasket which over time will loose it's elasticity and require re-tightening of the bolts. In my case I lapped the surface of the plate on the granite table with 320 grit sand paper until it was nice and flat, cleaned it with detergent and water to get all the oil residue off and then re-assembled it with new gaskets and the new Febi oil cooler.
I also found (perhaps obvious to any technician reading this) that as I torqued the the plate from the inner outward in a star pattern in 3-4 Nm intervals (like torquing a cylinder head). That I'd have to recheck torques at least 3-4 times around the complete pattern. I could walk away for a few minutes and check them again and notice a few needed to be re-torqued. Eventually they were all torqued and several checks around the torque pattern they were all about the same. I used a bending beam torque wrench with the pointer needle instead of a click lock style, so I could see the torque on each fastener.
After about 150 miles of driving it seem to be leak free.
For anyone doing this job in the future I recommend buying a new fuel cross over line (I'm told they aren't reusable, however I reused the one I have), and also replace the plastic Manifold and Thermal valve "while you're in there". I also recommend replacing the three hoses that connect to the manifold, EGR cooler and Thermal valve. It turns out the O-Rings on the Manifold are available from VW, and in fact the Manifold doesn't come with the O-Ring. There are two 90 degree elbow hoses one connecting to the EGR cooler (large bend radii) and another 90 degree elbow on the thermal valve to manifold connection as well as an almost straight piece of hose from the EGR Cooler to the Waterpump.
I will probably have to go back in and replace these in a year or three. I didn't have them on hand and the dealer didn't have any so I reused the old ones. However replacing these hoses later will basically require me to repeat the entire job.
I found the toughest part of this job is cleaning the mess in the engine valley. I used a very cheap bucket type shop vac to extract coolant from the hose on the water pump that connects to the EGR cooler and to vacuum up the oil goop in the valley area of the engine.
There are a lot of nooks and crannies in the valley area that if you want it perfectly clean (as I did) it will take several hours with to clean without getting anything into the openings.
In my case I put paper towels in the openings to catch any debris and vacuumed the debris before removing the paper towel and then inspected very carefully the oil cooler valve spring to make sure nothing got into the oil.
Overall the cleaning process took me about 6 hours with a few breaks. Some of the problem was the paint chipped off and I had to be sure to get all the gritty rust / paint mixture out.
Re-assembly took about 4.5 hours taking my time.
I'll post more details if anyone wants them and pictures and a parts list.
