GNB

I had the spark plugs replaced in July 2019 at 47K miles . The car now has about 70k miles .

The shop insists the plugs need to be replaced every 4 years , regardless of mileage.

My thought is to replace every 40K miles .

What are your thoughts?

desmotesta

given that they cost $35-$45 and take 45 minutes to do DIY I say just do it

PorscheAddict

The time interval for replacement rather than just mileage is to protect against the plugs seizing up and is cheap insurance.

GNB

Same shop also recommends replacing all the Ignition Coils . They say they should be replaced every 8 years.

Thoughts on this?

GNB

More than 45 minutes on a 991.1

subshooter

Try getting a spark plug out that snapped off while trying to remove it because it seized. Manual says every 4 years or 40k miles. I'd do it. There are people that waited to replace them at 100k miles without issue but not worth the risk.

The recall that the manual is silent on ignition coil replacements periodicity. They are super easy to replace during spark plug replacement (essentially no extra work). If it were me, I would wait until the next spark plug change.

Jordan911

As others have said it’s more for the not seizing up.

on coils it’s up you you. I personally change my own plugs so I didn’t pre emptively swap coils, since for me labor is free and I don’t mind getting back into it to swap them.

however if you are paying someone to do it, I’d probably do coils at the same time since they are right there, you wouldn’t get an extra labor charge

JimEb

991.1 is about the easiest spark plug change I ever did.

If you buy the plugs based on the Bosch part number you get the same plugs but avoid the Porsche Tax. I paid $4.26/each at RockAuto. A total of $25.56 for a spark plug change is pretty reasonable.

GNB

On replacing the spark plugs on the 991.1, other than working from under the vehicle, do you have to remove any parts to get access ( heat shields, etc.)?

Jordan911

theres a heat shield on both sides in front of the plugs/coils. But it’s easy to remove

GNB

Thanks! Do you remove the rear wheels for easier access?

Any of the plugs especially difficult to reach?

dannyk304

Hi there - first I'd say go to FCP Euro and get the kit - plugs, coils, dielectric grease. It was pretty cheap considering, especially with their lifetime guarantee so I'll do the plugs again soon and it'll be completely free parts! I did the plug changes myself, just after I bought the car and I had no experience with a 911 engine prior. I had 85k miles when I did it, service record showed they were changed at 40k. It was rather simple but you'll need an extension and universal joint to get to some, and a torque wrench. None were seized after roughly 45k miles on the car, they came out easy. There are two heat shields on each bank but these are minor inconveniences and it was good to clean them nicely while they were out. Yes, you need to remove the rear tires to get in there. If you don't have access to a lift it may be a little more annoying but if you're nimble and have a jack and stands that's more than sufficient. It's a nice way to connect to your car, and will save a bunch of $$. It took me about an hour total but I had a rent-a-lift (DIY Garage). There's a step by step article from truedriverscar.com that was very helpful. Good luck!

GNB

Thanks ! Porsche shop wants about $900 for parts and labor to replace plugs and all coils. I have always done this myself on other cars ( including a Corvette Z06 which had a rear bank plug that was a bit of a beast to reach. The cost quoted by the shop make you believe rocket science is invoived.

Jordan911

defintiely do yourself. Took me 2 hours probably and the longest part of that was just jacking the car up and removing rear bumper (not sure if you have to do, I did since I was running a back up camera in my vert)

SilverSFR

GNB
Look on you tube as there are many DIY or how to videos on changing spark plugs on a Porsche 991. You can review for your self if it is a job you can handle or not.