Spark plug change procedure

I could be wrong, but I believe that changing the plugs requires loosening the engine from the mounts to get to some of them because of the physical format of the Boxer engine. That doesn't mean it can't be DIY, but it does mean, if true, that it's not just an unscrew the old and screw in the new like it's been for many vehicles in the past.

On newer Subarus it isn't a hard thing to do as long as you take your time, have plenty of patience, and a good assortment of tools. I haven't done the ascent yet, but have done plug changes on 4 other Subarus, the spark plug tube is about the length of a spark plug socket and a short extension, if you have a wobble extension those have worked best for me as well as a good ratchet with a slim head. Keep some dielectric grease on hand to put on the coil plugs connection and springs, you might also take a look and see if the coils are showing any rust or separation thats usually an early sign of impending failure.

Ok now mentioned frequently is lifting the engine. Based on your experience would I be able to lift by obviously undoing what ever necessary, but by jacking a sturdy part of the engine? I don’t have a hoist to lift from the hooks or special Subaru tools to assist in lifting from above. The coils on both sides look even with the thick part of the frame.

cindyascent said:

Ok now mentioned frequently is lifting the engine. Based on your experience would I be able to lift by obviously undoing what ever necessary, but by jacking a sturdy part of the engine? I don’t have a hoist to lift from the hooks or special Subaru tools to assist in lifting from above. The coils on both sides look even with the thick part of the frame.

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Lifting the engine is generally not required, although it can be helpful but very time consuming. There should be enough space to get the coil off and plug out, only a couple of inches of clearance are required. Our tribeca with an H6 has almost no clearance on the last cylinder of each side, but the plug change is still possible without lifting the engine. H4 is generally not that bad.

Ruben Marin said:

Lifting the engine is generally not required, although it can be helpful but very time consuming. There should be enough space to get the coil off and plug out, only a couple of inches of clearance are required. Our tribeca with an H6 has almost no clearance on the last cylinder of each side, but the plug change is still possible without lifting the engine. H4 is generally not that bad.

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Has anyone ever actually changed the plugs on the ascent? I read a lot of theory and possibly but not an actual change. I attempted to change the plugs on my Ascent, but was only able to change them on the passenger side. Even after removing the battery, my 70 + year old hands fit hardly to remove the coils on the driver side. I really would like to know if it’s possible to change the driver side plugs without lifting the engine. Thanks.

Yes, through a very convoluted process of bending the coil pack boot and using multiple tools to get it in and out. Extreme care not to break the boot or cross thread the new plug, must be taken, to avoid creating bigger problems.

There are some battles worth fighting like oil changes and brakes pad replacement. And then there are some battles not worth fighting like changing the spark plugs on an Ascent. It was well worth it to me to pay the dealer to change them out. I even asked nicely and got a loaner car for the day.

RobertD said:

There are some battles worth fighting like oil changes and brakes pad replacement. And then there are some battles not worth fighting like changing the spark plugs on an Ascent. It was well worth it to me to pay the dealer to change them out. I even asked nicely and got a loaner car for the day.

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That's the same route I went. And I'd changed them on most of my cars since my 63 Biscayne through my 2010 Outback. Gave up halfway through doing the Ascent and decided it wasn't worth it.

Robert.Mauro said:

Yes, through a very convoluted process of bending the coil pack boot and using multiple tools to get it in and out. Extreme care not to break the boot or cross thread the new plug, must be taken, to avoid creating bigger problems.

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Thank you for your reply and enlightenment. I guess I will spend the $900 to have the dealer do it. I wonder if I will get a discount since I already changed two plugs.

Do you have another dealer near you to see if they charge less? $900 seems high to me.

The actual quote I received was $820 plus tax plus shop supplies. Recently, another dealer in Wesley Chapel opened and I may try to get a quote from them. Thanks again.