997 IMS Bearing & Bore Scoring
The short version: on a 997.1 Carrera, buy the paperwork and the bore scope. A documented IMS replacement from a known shop, plus a clean cylinder-labeled bore scope, is the combination that makes the engine a non-issue. No paperwork and no scope? Price the car like both jobs are still ahead of you. The rest of this page is the why.
What I'd do as a buyer
- Get the invoice for any IMS work: part installed, date, mileage, shop name.
- Get bore scope images tied to cylinder numbers, read by a specialist. On the M97 this matters more than the bearing for most cars.
- Ask whether the oil filter was cut open and inspected at service.
- Look at overall service continuity: regular oil changes at sensible intervals, with records.
Which cars are affected
The serviceable ball-bearing IMS and the bore-scoring question apply to the M97 engines in the Carrera, Carrera 4, Carrera 4S, and Targa cars of 2005–2008 (the 997.1). The 997.2 Carrera cars (2009–2012) use a direct-injected engine with no IMS bearing of this design. The Turbo, GT2, and GT3 run the Mezger engine in every year: different architecture, no ball-bearing IMS question, and coolant pipes are their maintenance conversation instead.
Bore scoring, plainly
Bore scoring is wear on the cylinder walls, worst on the bank-two cylinders of the 3.8-liter S engine. It shows as oil consumption, a ticking at idle, and eventually scored bores a scope can see. A seller saying "no bore scoring" without a scope is a claim, not a finding. The scope is a few hundred dollars of inspection time on a five-figure decision.
What the data says so far
The 997 dataset is young. Adjustments for documented IMS work and clean bore scopes are not yet measurable in it, so the calculator applies none and says so. On the 996, where I have hundreds of sales, documented IMS work measures +7.8%. The 997 gets its own number when its data supports one, not a borrowed one.