Part five: Having removed the engine, we try to diagnose what is causing the running problems.
We had initially thought that things couldn’t get any worse with our Insignia after realising the engine needed a rebuild, but more bad news hit us this month. In fairness, some of it should have been expected. For instance, we found one of the sources of the coolant residue around the lower half of the engine block: the water pump is leaking and doesn’t look particularly new, so it probably wasn’t changed when the timing belt was renewed last year. Also, the clutch looked relatively new, but it appears the dual mass flywheel wasn’t changed at the same time and it’s not in good shape.
However, these servicing short-cuts were only the tip of the iceberg as we stripped down our Insignia’s engine.
The biggest horror came when we removed the diesel particulate filter and found a large rectangular-shaped stitchweld on one side. We suspect the innards were removed to resolve any DPF issues and consequently the ECU may have been remapped. Legally speaking, we must resolve this by fitting a new DPF and having the ECU checked.
If that wasn’t bad enough, when we delivered our dismantled engine block to our local machine shop, they cracktested the crankshaft and it failed. They also found that the main bearings caps had distorted and hardened, so there was no point in line-boring them because the material would be difficult to remove. Plus, the distortion meant they were no longer a tight fit to the engine block.
Fortunately, there is some good news. Our local machine shop wasn’t that concerned over the condition of our engine. It spends a large proportion of its time dealing with these sorts of problems. In fact, at the time of our visit, it had line-bored SIX of these engines the day before!