Documented forum build · 964 · air-cooled
1990 964 Carrera 2 3.6 rebuild
A leaking 192,000-mile 1990 Carrera 2 progressed from an intended in-car reseal to a split-case 3.6-litre rebuild after a broken cylinder-three head stud was found, with owner documentation through first startup and an 8,000-mile follow-up.
Evidence: Opening thread page — reseal, broken stud and full-build decision · Page 2 — machining, rotating assembly and oil-system preparation · Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation · Page 6 posts 84 and 88 — installation and first-start result · Same-author post 3 — 8,000-mile rebuild follow-up
- Vehicle
- 1990 Porsche 964 Carrera 2
- Engine
- 1990 964 Carrera 2 3.6-litre flat six with 192,000 miles → Rebuilt 3.6-litre 964 flat six with new Mahle pistons and cylinders and reconditioned rotating components
- Forum
- Rennlist
- Thread author
- Meatball964 · 18 July 2017
Vehicle and engine evidence: Opening thread page — reseal, broken stud and full-build decision · Page 2 — machining, rotating assembly and oil-system preparation · Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation
Why it came apart
Multiple oil leaks prompted the reseal, but a broken cylinder-three head stud changed the plan to a top-end job and the mileage then led the owner to split the case for a complete rebuild.
Source: Opening thread page — reseal, broken stud and full-build decision
What the project aimed to do
Address the leaks and broken stud once, inspect the high-mileage bottom end and return the engine to long-term road service rather than repeat the removal later.
Source: Opening thread page — reseal, broken stud and full-build decision · Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation
Who did what
The owner performed their first engine drop and documented the teardown, preparation, assembly and installation with help from forum members; Ollie's handled specialist cleaning, inspection and balancing of the case, crankshaft and connecting rods.
Source: Opening thread page — reseal, broken stud and full-build decision · Page 2 — machining, rotating assembly and oil-system preparation · Page 6 posts 84 and 88 — installation and first-start result
The newly purchased C2 had 192,000 miles when the author began what was initially intended to be an in-car oil-leak reseal.
Vehicle context: Opening thread page — reseal, broken stud and full-build decision
Documented sequence
Scope expansion and teardown
The project moved from an in-car reseal to an engine drop, top-end rebuild and finally a split-case rebuild after the broken stud and high mileage were considered.
Source: Opening thread page — reseal, broken stud and full-build decision
Machine work and oil-system cleaning
The case and oil passages were cleaned, the crankshaft was inspected and balanced, connecting rods were re-bushed and balanced with ARP bolts, and the oil tank, cooler and lines were removed for cleaning.
Source: Page 2 — machining, rotating assembly and oil-system preparation
Case and piston-cylinder assembly
The case was sealed with Loctite 574 before new Mahle pistons and cylinders were weighed, cleaned and installed with their ring positions checked.
Source: Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation
Installation and first start
The rebuilt engine, replacement dual-mass flywheel and associated parts were installed; the author then reported a successful first start after resolving a fan noise attributed to belt tension.
Source: Page 6 posts 84 and 88 — installation and first-start result
Mileage follow-up
A later same-author Rennlist post reports approximately 8,000 miles on the rebuilt engine when the car reached 200,000 total miles.
Named components and work
Crankshaft, rods and chains
Magnaflux-inspected, cleaned and balanced crankshaft, re-bushed and balanced connecting rods with ARP bolts, a new nose bearing and new timing chains are recorded after specialist preparation.
Source: Page 2 — machining, rotating assembly and oil-system preparation
Pistons and cylinders
A new Mahle piston-and-cylinder set was weighed, cleaned and assembled after the case halves were closed.
Source: Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation
Oil circuit
The oil tank and cooler were cleaned and refurbished, while the external oil lines and thermostat circuit were removed, flushed and checked before startup.
Source: Page 2 — machining, rotating assembly and oil-system preparation
Reported outcomes
Forum-author-reported first start
Successful startup on 19 August 2018
The author reported the engine running and a fan ping that disappeared after the initially tight belt settled; the next planned step was refill and road break-in.
Source: Page 6 posts 84 and 88 — installation and first-start result
Forum-author-reported mileage follow-up
About 8,000 miles on the rebuild
In September 2019 the same author reported this mileage while marking the car's 200,000-mile total; no independent inspection accompanied the statement.
Evidence limits
- The first-start and 8,000-mile results are forum-author reports and were not independently verified.
- No dyno, final compression or final leak-down measurements were identified in the reviewed posts.
- The complete M64 engine sub-code is not stated in the cited posts.
- The 8,000-mile result appears in a later same-author Rennlist thread rather than the original rebuild thread.
- Fresh automated requests to the main thread returned HTTP 403 from the forum's bot protection; the cited material was reviewed through public browser-indexed pages without authentication.
Access note: The thread pages and same-author mileage follow-up were publicly readable in browser-indexed forum pages without account authentication. Raw automated requests to the main thread met the forum's HTTP 403 bot protection when rechecked.
Reviewed source trail
- Opening thread page — reseal, broken stud and full-build decision · reviewed 2026-08-25
- Page 2 — machining, rotating assembly and oil-system preparation · reviewed 2026-08-25
- Page 3 posts 32–37 — case closure and Mahle piston-cylinder preparation · reviewed 2026-08-25
- Page 6 posts 84 and 88 — installation and first-start result · reviewed 2026-08-25
- Same-author post 3 — 8,000-mile rebuild follow-up · reviewed 2026-08-25