My 1997 Toyota Camry had the engine replaced in January '07.
Replacement engine had about 50,000 miles and all other parts from the old engine were used, including re-machined head.
The engine ran beautifully and had one oil and filter change in the 3,000 miles since the work was done.
One week ago, noticed the oil light was coming on or flickering at stops. Drove to same mechanic the next day. During the drive all systems appeared normal (temp gauge reading, engine sounds, except oil light at stops). Prognosis: 1) oil pressure tested at low end of range at all rpms, 2) crack in radiator, 3) metal in oil pan, 4) crankshaft bearings shot, 5) crankshaft scorched, 6) recommend engine rebuild. 7) damage appears to be caused by overheating. All according to the mechanic.
Question: Can this major problem happen with no outward signs (i.E. The temp gauge seemed to work normally, registering the engine temperature from cold to just below mid-range, no knocking or other noise from the engine, etc. The car ran fine)? Should I get a second opinion?
If it is believed to be from overheating due to a crack in the radiator, Then I would expect to possibily seen coolant leaking, a low coolant level, a temp gauge indication at least. I would certainly want to pull the plugs and look for any signs of internal coolant leaking and burning.
Not to say this happened, but if the head was mis-installed so that coolant was entering the cylinder (s), the cooling system could have been pressurized, cracking the radiator. Still the coolant level and temp gauge should have given indications. Which came first the cart or the horse? Toyota engines are pretty durable, a second opnion may help but may still be left to speculation.