RESOLVING LOW OIL PRESSURE
1 With the Insignia parked on the driveway, we needed to get it to MJ Motors, who are helping with this project. They’re 12 miles away, but also close to Autovaux, so spares can be ordered and delivered quickly. We used a local transport company to move our Insignia.
2 Dan Smith at MJ Motors suggested draining the overfilled engine oil. It may be above the ‘Max’ mark due to a DPF regeneration not being completed, dumping diesel fuel into the engine oil and lowering the oil pressure.
3 After lifting the Insignia on a two-post ramp, the engine undertray was detached by undoing a couple of quickrelease plastic fittings, then left suspended on its front mountings (it’s hinged across the front for easy access to the sump). The base of the sump was coated in oil and there were traces of engine coolant residue.
4 The 13mm sump plug has a banjostyle drain hole, which means it can be slackened to allow the engine oil to be steadily drained. This also avoids the risk of oil surging out when the drain plug is removed and either missing the drain-pan or running down your arms.
5 Unfortunately, the engine oil is viscous. Realising it could take the rest of the day to drain, we decided to remove the drain plug, allowing the oil to drain out much faster.
6 After refitting the drain plug, we poured four litres of 5W-30 fully-synthetic low ash oil into the engine, then ran it to see if the low oil pressure problem had been resolved. It hadn’t, and the turbo was still sounding noisy, suggesting it’s being starved of oil.
4 The induction pipework between the air filter housing and the compressor housing of the turbo was undone. Both ends are secured with Jubilee clips and there’s also a breather pipe and sleeving around the compressor housing to detach.
5 The pipe between the compressor housing and the intercooler is secured with two E12 bolts. There was just enough room to squeeze a socket and 3/8 in ratchet into position and undo them.
6 Despite the luxury of having easy access to the turbo, some of the fittings were not so straightforward to undo. For example, the two 10mm bolts securing the oil drain pipe to the turbo have usually seized (penetrating fluid was sprayed over them) and only the frontm ost bolt could be undone at this stage.
7 We had been given a new oil feed pipe from Autovaux. It’s a short metal pipe routed from the top of the engine to the top of the turbo and is known to become blocked, thus starving the turbo of oil. Each end is secured with a Torx T45 bolt.
8 The turbo is attached to the exhaust manifold with three 11mm nuts. The easiest of the three is accessed from above, as shown here. Our nut had seized, so the stud came out with it, which was a help when it came to removing the turbo.
9 The other two 11mm nuts that hold the turbo onto the exhaust manifold were not so easy to undo. We sprayed them with penetrating fluid, then slowly wound them undone. There’s not much room, so this took several minutes.
10 Finally, the turbo was released. It was lifted up to access and undo the remaining 10mm bolt for the oil drain pipe (see Step 6) and detach the plug connector for the actuator. Now the old turbo could be lifted free from the engine bay.