Feasibility of replacement of Subaru Outback 2007 3.0L Cylinder heads

Question

As noted I have a 2007 Subaru Outback with a V6 3.0L engine. It appears to be front-wheel drive. The head gasket(s) need replaced and possibly the cylinder heads. I used to work on cars 25-30 years ago (now I do software development, hands stay cleaner) and have all the tools I need. I've also got the space to lay out parts and bolts and another car so no time crunch.

Due to a dumb mistake on my part (also a good quality is admitting my mistakes) related to the thermostat, the engine overheated and I'll need to a least replace the gaskets but probably re-machine the heads or just replace with remans.

Is this a feasible operation for me, and given that an experienced mechanic said 99% of the problems are going to be in the head(s), and approximately how much in labor would I save by doing this?

Answer 1

It's a reasonable job once these wide engines are removed from the vehicle. I was quoted US$2-3K at a reputable Subaru workshop. As requested here's some docs to estimate doing the work yourself;

Subaru Legacy/Outback Factory Service Manuals

Subaru H6 Technician Reference Booklet

There's also a couple videos on YouTube and good resources at subaruoutback.org, note that some folk prefer to buy and install a used JDM engine over rebuild.

Answer 2

Your big saving will be in labour, but you're still going to be in it for over $1,000.

How many miles on the engine? How bad was it overheating? If it was at the end of one journey, and you then stopped and didn't drive it to overheating again, you won't need new heads (you can measure the deflection to see if a skim is needed)

The engine is connected to the gearbox by less than 10 bolts (plus the torque converter bolts). It's a tight fit, but if you have experience you can get it out and onto a stand in an afternoon (less, if you can get the car into the air to get the lower bolts)

Once it's out, there's a shopping list of things that it's best to replace, e.g tensioners, water pump, thermostat (with a Subaru one this time :) ), timing chains, plus a few other things. Note that if you put a JDM (Japanese Domestic Market) engine in anyway, you'd still have to replace all these.

There are a couple of Subaru forums around with good videos and text walk throughs - people are glad to help. Get hold of the correct Workshop manual for all the torque settings.

Once you've done it once, you'll end up taking the engine out for basic maintenance every year or so because it's so easy, rather than fighting to get those spark plugs in!