1991 Lancia Delta 1.6L Petrol · H104 XAB

The Delta's monocoque chassis was originally conceived for a modest 1.3-litre family hatchback. Channeling over 200bhp through stiff 4WD suspension, aggressive anti-roll bars and modern low-profile tyres subjects the shell to immense torsional loads. Severe stress cracking frequently develops at the upper corners of the windscreen pillars under the rubber seal, around the front bulkhead chassis leg attachments, down at the bottom of the B-pillars and around the rear suspension turret perimeters.

The turbocharged 2.0-litre Lampredi engine features twin overhead camshafts and twin counter-rotating balancer shafts driven by independent toothed rubber belts. High-temperature engine bay conditions, high-lift camshaft modifications and tight clearances accelerate belt degradation. If the cambelt or balancer belt snaps or skips teeth due to aged tensioner bearings, the valves impact the pistons, resulting in bent valves, broken guides and major engine rebuild costs.

Unlike earlier Lancias, Integrales received improved factory cathodic dipping, but specific moisture traps remain notorious. Rainwater and road grit collect in the channel seal where the tailgate hinges mount to the roof trailing edge, causing bubbling and structural disintegration that weakens the tailgate mountings. Similar corrosion takes hold behind the windscreen rubber seal and around the front lower scuttle, requiring painstaking metal fabrication to rectify.

The transverse Lampredi turbo installation is prone to oil weeping from the two-piece sump gasket and rocker cover seals. In aggressive driving, the turbocharged twin-cam engine consumes up to 0.5 to 1.0 litre of synthetic oil per 1,000 miles. Because the turbocharger oil feed gallery sits high up on the block, running with low oil levels rapidly starves the turbo bearings and big-end bearings, resulting in bearing seizure and turbo failure.