Just in case, here is a copy of my original text and photographs from BigJimny forum:
My DDiS Jimny recently developed an extremely annoying issue with coolant distribution system. Through my research, I discovered that it is a common issue with DDiS Jimnys which have 63 kW K9K 266 engine.
The problem:
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The issue is simple in nature - one plastic three-way hose manifold in the coolant distribution system gets eaten out by the coolant over time (bad quality plastics), and starts leaking coolant. The leaking is minor at first, but after a few thousand kilometers it gets so severe that it requires replacing the manifold.
Suzuki part number of the original manifold is 17878-84A5.
My investigation shows that this manifold is used only in DDiS Jimnys with 63 kW K9K 266 engine (technical model name of the car: SN415VD Type 6 and 7). Earlier DDiS Jimnys with 48 kW K9K 700 engine (technical model name of the car SN415VD Type 5) have a completely different coolant distribution system.
However, there are two major issues with replacing this manifold:
- Manifold is of special shape and design as well as pipe diameters, so it is pointless to try to find a similar one in car junk yards (believe me, I tried).
- If you order the original replacement manifold from a Suzuki dealer, you will wait a long time, as it is not a standard stock item, not even in major Suzuki warehouses in Europe. Also, the replacement will have the same quality issue and will probably need another replacement after approx 100-150 thousand km.
- Manifold is located behind the engine towards the passenger cabin, and it is very hard to reach. Essentially, you have to disassemble half of the engine to reach it and be able to manouver around it.
The solution:
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Considering all that was said above, I decided to make a DIY replacement manifold, with the help of a friend who is a professional installer of central heating systems.
Therefore, we made a DIY manifold out of copper pipes connected by tin solders. The same pipe connections are used to transfer hot water between radiators in central heating systems in homes and offices. This solution should have eternal longevity.
The only downside in this solution is that the manifold is larger in total size than the original one, as the copper pipe elements could not be shortened that much. But since half of the engine had to be disassembled anyway to access the manifold location, installing this larger one should not be so much more difficult.
I have provided all photographs which show the location of the manifold in the engine bay, the original manifold taken out (notice that two of its pipe connections are broken - in fact they were so worn that they crumbled during disassembly), and photo of the DIY manifold next to the original one.
I hope that this gets useful to someone.