This question concerns a 2004 Subaru Outback with ~167,000 miles. All major and minor maintenance was performed (original owner car). Nonetheless, it has suffered rapid demise. How much of the following are age-related coincidences — or possible consequences of the car overheating due to a cracked radiator and a simultaneous head gasket failure?
As of this year:
Valve cover gasket (slight oil leak) Radiator cracks (plastic content cracked) Head gasket fails (belatedly appreciated as a known issue on some Subaru models) Car overheats and dies at a stop.
Repair: Replaced inoperable accessory fan, valve cover gasket, machined valves; head gaskets replaced, thermostat replaced, radiator replaced, motor mounts replaced, transmission mount replaced.
Less than 24 hours after receiving the car from repair, car fails at highway speed stranding spouse and myself on a freeway.
Repair: Six bent valves replaced. Shredded timing belt replaced. Stripped out bolt that holds the timing belt tensioner and a pulley repaired. Car passes compression test. Mechanic insists that tensioner, pulley, water pump and other components do not need to be replaced (car had had the belts, water pump, tensioner and the like replaced less than three years prior).
On day of pickup, the car began making a high pitch whine or whistle on acceleration to highway speed and seemed to be lagging when attempting to reach highway speed (RPM spikes). Upon exiting the car, burning odor and smoke was observed from the engine area. Car was again left with mechanic.
Diagnosis: Rack-and-pinion is leaking fluid onto the exhaust. Requires replacement. The high-pitch sound is emanating from the muffler, but shop says they don't know what's causing it.
One week later informed by shop that there is another noise upon acceleration. Drive shaft recommended for replacement. (Too much play causes a stutter sensation when accelerating from a stop.) Indeed, when we come back to test drive the car, there is a new problem present. (In addition, muffler noise is still present but not diagnosed.)
Current status: Muffler shop is performing a compression test. Concern is that the catalytic converter, which is less than three years old — because it was replaced under an unrelated Subaru recall! — is failing. Likely culprit from what we have read for why the car doesn't accelerate as well and emits a high pitch whistle is a failing cat (probable overheat consequence). Subaru says that the cat they installed was warrantied for only one year — so we are SOL on having them service it under any kind of CA emissions warranty.
In summary how much of the above is or is not related to the overheating that occurred with the radiator and head gasket failure — or the fact that the timing belt failed at highway speed immediately thereafter?
Given that we have had access to the car for less than one 24 hour period over the past seven weeks and numerous new problems have appeared, should we suspect any mishandling on the part of the mechanic — or chalk it up to bad luck?
Lastly, what other "shoe" may drop as a result of the overheat and belt breakage that we need to be on the lookout for? At issue is that we are over $2,000 into these repairs — having not yet completed the rack-and-pinion and drive-shaft replacement — and we'd like to know if we've seen the worst that can happen after the major failures indicated above. Is it likely we've seen the worst — or could it go from bad to worse?