Pre-purchase walkaround
1980 Porsche 911 SC (G-Series)
76,000 miles · asking $60,500
Five-year cost to own, maintenance and fuel
~$6,800
The 911 SC is a robust, honest air-cooled 911 that bridged the mid-70s cars and the 3.2 Carrera. Money goes into engine seals, chain tensioners, the airbox, and rust remediation on cars that lived outside.
The roadmap
76k → 136k mi · 12k a yearYear 1The ordinary rhythm: scheduled work and fuel.~$734
Year 2Suspension comes around again.~$2,281
Yrs 3-5The quiet year. · Brakes and consumables.~$3,795
Five years, all in~$6,800
typical parts + government labor rates (national labor rates) · an estimate, not a quote
What to look for on this one
Every used example of this chassis has the same questions. The bands show when each tends to surface; the gold line is this car at 76,000 miles.
Valve guide wear$350-$1,250 if not done
0typical window 80k-150k · this car: 76k, ahead of it150k mi
High-mileage air-cooled heads wear guides, leading to oil past the valves. Common on cars overdue for a top-end refresh. Blue smoke on startup or overrun and rising oil consumption.
Body and chassis rustpriced only if found
Condition-driven, not mileage-driven, so it is not in the totals and inspection is the only answer. Bubbling at front and rear fenders, kidney bowls, battery box, floors, and windshield surround.
windows from 0 owner complaints on file with NHTSA and community service data · · profile researched with cited sources, review pending
0 recalls →
Hand this to your inspector
A $300 inspection against this list is the best money in the whole deal.
01Confirm whether the chain tensioners have been upgraded to the pressure-fed Carrera units, ask for receipts
02Cold start and listen for chain rattle and watch for startup smoke indicating valve guides
03Inspect the airbox for cracks or evidence of a prior backfire repair
04Probe the kidney bowls, battery box, floor pans, and front suspension pan for rust and filler
Walking into a negotiation?
This roadmap as a PDF, priced for your zip code, with the inspection checklist, a fair price for this example, and the negotiation sheet. Saved to your garage the moment you pay.
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saved to your garage
Just keeping tabs? , no account needed.
typical parts + government labor rates · an estimate, not a quotecheck another car →