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2006 Subaru Outback slow oil leak

For years I’ve heard you extol the virtues of the Subaru Outback. I bought a 2006 with 97K miles a few years ago. The car has a slow oil leak from what I’ve learned is the usual place. I’m told that to replace the valve cover gaskets and reseal the cylinder head is a $2500 job. That’s just nuts. I guess most folks who buy these cars only keep them a few years, then trade them in BEFORE the infamous Subaru oil leak strikes. I’m going to keep driving it for now, but plan to look elsewhere for the next car. OBTW, love your show and your articles. Have been listening for many years. cheers!

Tom and Ray don’t do the show anymore; Tom’s passed, and if you are hearing the show on your radio, it’s the Best of Car Talk re-runs. Most of us don’t get the show on the radio now, so we listen via this website’s podcast.

For the oil leak, if you aren’t sure where it is leaking from, a shop can clean the engine off and put a dye in the oil so you’ll know for sure. If you feel lucky you could just replace the two valve cover gaskets. That’s not overly expensive. If the problem is the head gasket, yes, that’s pretty expensive. But usually when that blows it causes a cooling system problem. Are you having any cooling system problems?

George: No cooling problems here. Just a pesky slow seepage of oil that’s apparently been going on for many miles. I just had the ABS module replaced, to clear various fault codes and flashing lights, so we’ll just live with the oil leak for now. I expect 200K out of these things, so we’ll see!

thanks for your advice,

cheers, Mark

Reseal the cylinder head? Haven’t heard that one before. Maybe you mean replace the head gasket. I’ve heard a typical leak for that engine is the front cam seals. That’s why many owners replace them while replacing the timing belt, the mechanic’s already done lots of labor to get in there so better to replace non-leaking ones then and not have to go back in later.

Subarus have a cult following which has always baffled me because they’re famous for blowing head gaskets. And that was before they had their famous oil-guzzling problem with defective piston rings. It didn’t help that it took a class-action suit to get Subaru to stop stonewalling their customers.

A thrifty friend of mine has owned Outbacks for years by buying them cheaply at about 90K miles with a blown head gasket, replacing the head gasket, timing belt, water pump, and seals and off he goes for years of trouble-free driving.

My advice for you is get the leak diagnosed now. If it’s just valve cover gaskets they’re cheap and you won’t be breathing oil fumes inside the cabin. Find out if the timing belt was replaced by the previous owner at 90K. If not, you’re overdue. No one in their sane mind wants to drive around with an overdue timing belt in any car. If you need a head gasket you won’t be able to sell the car for what you paid for it so if you like the car, get the head gaskets done before you damage the engine and/or get stranded somewhere. Once that’s done you’ll be driving a nice car for at least the next 100K miles.

A little late for this now, but if you had had a mechanic familiar with Subarus check the car before you bought it he would have checked for oil leaks first and checked if the timing belt had been neglected.

When you say “the usual place” that could also include the spark plug tube seals. Replacing those is a matter of maybe $250-300. That involves replacing the valve cover gasket but is a whole lot easier than other options.

Lee: I had the timing belt, water pump and coolant exchanged at 110,000 miles. My mechanic uses the term ‘resealed’ to indicate a head gasket swap, and that’s where the leak is. At any rate, I’m done with Subaru. Will drive this one until the leak gets bad, then donate it.

Thanks for your detailed responses. You’ve confirmed all that I’ve learned along the way!

cheers, Mark

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OK, I’ll check that as well. Thanks for the tip!

Coincidentally, the engine has started idling VERY low at stoplights. (Gauge says 400 RPM.) When first started up, it won’t even hold 400 turns and starts to stall. I have to raise the idle to 1500 or so at stops. Also, the A/C compressor cuts out when it goes low. Once the throttle is advanced, it blows very cold. Could another of these vaunted Subaru computer modules be starting to fail?

That could be a problem with the idle air control (IAC) mechanism. Or, if this is a drive by wire design, the electric throttle body.

Certainly the choice is yours Mark but you know the saying, good for a dime, good for a dollar. Ideally people who buy an Outback with those miles either know the head gaskets have been replaced or pay a discount knowing they’re in for a $2500 repair. The problem is driving a car with a leaking head gasket or 2. Typically they will leak coolant into the oil and not oil to the outside of the engine. If you check the dipstick and it looks gooey then that’s coolant and you either do the repair or donate the car. Unless you paid very little for the car I would replace the head gaskets. These are nice cars when all is well.

Great info. A buddy of mine of having almost the same problem on his Subaru closing to 182k miles mark. He mentioned the leak is increasing and noticed the slight cooling system problem. We’ll take a look at it right after we finished installing the new rack and MX4 bakflip tonneau covers on his current truck project. Hope it is not that bad.

Flash: No coolant loss that I can see in the oil. Engine temp normal. I’ll continue to investigate. Thanks for your reply!


I certainly agree that they’re nice cars, with that “when all is well” caveat! At any rate, I’ll continue to investigate. I have friends who’ve recently purchased new Subarus. I will recommend that they do the valve cover and head gaskets when they get to the timing belt replacement point.

cheers, Mark

Thanks George. I’ll have my guys check the IAC when I get it back to them.

cheers, Mark

new ones have a timing chain instead of a belt, no replacement needed.

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Maybe true for the 6 cylinder but the 4 still has a timing belt.

A head gasket replacement should never be necessary as part of maintenance. I’m pretty sure Subaru’s engineers have remedied the head gasket problem along with the piston ring problem. My girlfriend bought a '16 5th gen Outback despite my doubts - the car is a complete redesign, it’s bigger, very luxurious, rides great. If it turns out to be an oil-burner or head gasket-blower I’ll feel about Subarus the way you do now.

no, the opposed 4 has a chain.
this is the FB25B engine
this is the 2015 model, I assume this applies to later years also.

Engine 2.5i: 2.5 liters, 4 cylinders, 16 valves
Interference type. FB25B
timing chain - no replacement needed
HP: 170 hp @ 5,800 RPM
Torque: 174 lb.-ft. @ 4,100 RPM

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I bought the famous Subaru 2004 and didn’t know it had head gasket leaks. I got those fixed for about 1400 and it still been good for 2 years. Now I have a crankshaft oil leak ($600 repair)I parked my car for both events to raise money by canceling the insurance and giving up paying for gas because these oil leaks can ruin the engine. My head gaskets were leaking radiator fluid into the oil I didn’t have any overheating but the car couldn’t take any Outback treks up dirt hill roads. I rode city buses and my bike or got help with rides with friends and family. The second oil leak of my crankshaft I’ve learned can mess up the timing by leaking onto the timing chain and ruin the engine. Otherwise the car runs great at 185000 miles. Yes there are the infamous oil leaks but I wouldn’t recommend still driving it. Find out about these leaks on YouTube. Both my repairs include new timing chain and water pump. But think on the bright side, new cars cost a lot and I plan on driving my car to 300000 miles like I did my 2 other Subaru. The engines are long lasting though my 89 had clanging valves.

Read my post on head gasket leaks and crank shaft seal leak. Not ok to drive if you have these. Good luck. Many mechanics will do free look for your problem.

I got away with paying 1400 for my gasket seal replacements but now am doing crankshaft seal at 600 Both include new timing chain and water pump. Shop around for estimates and do not have it done at a Subaru dealership.