Part eight: Having painstakingly rebuilt our Insignia’s seized engine, have all of our efforts proved worthwhile?

PART EIGHT: Rob Hawkins crosses his fingers in the hope that the Insignia engine will be up and running.

We’ve had our fair share of problems with our Insignia, so it was a surprise when we asked a specialist to strip the gearbox and they found nothing wrong with it. There was no excessive wear and no traces of leaks. In a strange sort of twist, with a magazine’s project car problems are welcome because they make for good editorial. However, the healthy gearbox was perhaps a blessing, because – as you’ll see over the following pages – there were yet more problems with the engine that were set to sting us.

We thought we had been sufficiently cautious. We even sent the injectors for testing and had one of them repaired, then renewed the clutch and dual mass flywheel (DMF), and fitted a new Klarius diesel particulate filter (DPF) instead of the illegally modified unit that had been fitted by someone else!

Lowering the engine back into the Insignia, we were keen to hear it run. So once it was sufficiently connected up, we dipped the clutch and pressed the start button. The engine turned a few times, then stopped. A few more attempts saw no movement and eventually a whiff of smoke appeared from around the starter motor. The engine had nipped up, as though a bearing had come loose.

Engine out again

Watching the mechanics at MJ Motors work through the problem of the locked engine would serve as an article in itself. We discussed the possibility of the starter motor being to blame, but realised there wasn’t much we could do without removing the engine and gearbox from the car again. So that’s what we did.

With the engine removed, the gearbox was unbolted to see if this was the problem (highly unlikely, because the clutch has to be depressed to start the engine) and to further inspect the dual mass flywheel. No problems were found; the crankshaft could only move back and forth by a few degrees.

Next, we removed the sump and initially suspected the skirts of the pistons were fouling the crankshaft webs, but this was dismissed once we squeezed our fingers into position and found there was sufficient space. The timing belt was detached, in case there was an issue with the camshafts, but the crankshaft still refused to budge more than a few degrees.

We didn’t expect there to be any problems with the main and big end bearing caps, especially after checking their play using Plastigauge, but we nevertheless removed them and found the crankshaft was still stuck.

Finally, we extracted the thrust bearings and discovered the cause of the problem. One of the thrust bearings was damaged and, unfortunately, we had fitted it the wrong way round. We’re only human and mistakes occasionally happen. Luckily, the crankshaft had survived and a new set of thrust bearings was fitted. This time, the engine rotated freely and, once installed, fired up and ran.