hmm oil leaking onto steering rack and rearwards on undercarriage to trans

[darthqwo]

It is a 2008 legacy 2.5i na, and it appears as oil seeping over the underside of trans, and colour from here was unclear, but i suspect this may have traveled there while driving, as i noticed when on a lift that the rack itself has oil dripping from it of conventional oil colour, not like red. The oil on the steering rack also look to be fresh oil, not burned like the one being drained (i.e.; setting was an oil change).

 

Without a steam clean mechanic suggest possible steering rack leak or head gasket.

 

Im inclined to think my symptom would seem a bit early for blown head gasket, given I don't have any check engine lights, nothing wasmentioned unusual in coolant reservoir or oil tank. Per https://legacygt.com/forums/showthread.php/hydrocarbons-coolant-186939.html i will do a hydro carbon test to check, but there is a young child on youtube with sti who posted something very similar to my own leak that turndout to be a cracked pcv elbow pipe; does this also apply to nonturbo engines (anyone? omg thanks.)

 

About 1.5 years ago my valve cover gaskets were replaced along with a coolant flush at about 120000. Is this reason to think that as I approach 150000 miles, the headgaskets are at risk? Research suggests it plagued prior gens and persisted even in 4th; is every 4th gen head gasket on sohc 2.5i engine eventually going to fail despite proper maintenance?

 

Appreciate any input! omg thanks.

[lockmedic]

the 2006+ AVLS motors have headgasket failures that typically manifest as external oil leaks. They don't "blow" in the sense that the combustion chamber is compromised or oil/antifreeze exchange or find its way into the combustion chamber. Just leak.

 

It's relatively benign aside from the mess. They don't leak much but keeping an eye on the oil is a good idea. I've seen them leaking at 90k miles.

[darthqwo]

hmm given i have not looked ever under the car until past few months, i'm actually not sure how long it has had the oil leak or if prior issue with side gaskets was misdiagnosed.

 

can i get your opinion on if these motors are sensitive, at least at this stage, to the type of oil & antifreeze used? would the subaru oem coolant conditioner help the leaking 4th gen avls motor? (omg thanks)

[lockmedic]

Antifreeze, yes. Oil, probably not so much but I don't know. No idea what causes the gaskets to leak oil but subaru has been chasing that rabbit since the first EJ25 appeared in 1995.

 

My guess is the root cause is thin headgaskets.

 

FB motors solved the problem by moving all the oil passages (feed and return) to the timing cover.

 

Flush/refill with subaru long life coolant and conditioner would be beneficial for other reasons but nothing will bring the gaskets back to un-leaky condition other than replacement, which I would not consider necessary unless you're seeing evidence of leaks on the concrete when parked overnight or losing more than a quart between changes.

 

My guess is the valve cover gaskets probably weren't leaking. They rarely do aside from the spark plug tube seals, which you don't actually see the evidence of that until you change plugs as it drains down into the tube and collects around the plugs.

[darthqwo]

My local subaru recommends the oil 0w20 full synthetic from subaru--just noting; somewhere in the forums the oil of choice is 5w50. The subaru guy also revealed his 2006 impreza leaked from the head after the first year. The best explanation I came across suggests the boxer shape of the engine itself and maybe battery-induced corrosion of the coolant together. But then again, it mainly affects the sohc 2.5 engine, right?

 

Actually the setting in which my valve cover gaskets were diagnosed was after doing the spark plugs. So leaking spark plug tube seals would induce leaking valve cover gaskets? or do you mean they would leak separately? I wonder if the problem was even fixed; it might be leaking from the same spot as well as the head gasket or just one--no clue ��