Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

Overview

This guide goes through the steps we used to replace all six spark plugs on a Porsche 911 (991.1). Porsche states to replace spark plugs every 4 years, or every 40,000 miles (60,000 kms). Change the spark plugs on Porsche's flat six engine is not any different than any other engine. The difficulty is gaining access to all of the spark plugs. It took plenty of patience and finesse to work in such a tight area. With some creativity, plenty of extensions, universal joint, and various types of 3/8" ratchets, such as this 3/8" drive extendable ratchet, we were able to get the job done without completely ruining our knuckles. When you were at the hardware store and saw that weird looking ratchet or extension, this is the type of job when those tools earn their keep ten fold!

One final note, since this maintenance is usually done at the same time as the engine oil change, be sure to change the spark plugs FIRST, before the engine is hot.

Parts Used

Part	Quantity	Part No.	Links to ones we used
Bosch Spark Plugs (set of 6)	1	Bosch FGR5NQE	Amazon

Tools Used

Tool	Link
Quick Jack BL-5000XL portable lift	Amazon
Jack Stands	Amazon
3/8" Drive Ratchet	Amazon
3/8" Drive Torque Wrench	Amazon
3/8" Drive Extension	Amazon
3/8" Drive Universal Joint	Amazon
E10 (External Torx) Socket	Amazon
T30 (Torx) Socket	Amazon
16 mm 6-Point Spark Plug Socket	Amazon
10 mm 6-Point Socket, 3/8" Drive	Amazon
10 mm Combination Wrench	Amazon
Craftsman 3/8" Drive Extenable Ratchet ¹	Amazon
Milwaukee 3/8" Powered Ratchet ^1,2	Amazon
1/2" Drive Ratchet ³	Amazon
1/2" Drive Torque Wrench ³	Amazon
19 mm 6-Point Socket, 3/8" Drive ³	Amazon
Porsche Wheel Guide ³	Amazon
DeWALT 1/2" Impact Wrench ^1,3	Amazon

¹ Not necessary to complete this job, but sure makes it a lot easier!

² Use only for removing bolts/nuts and

³ Used for wheel removal (not pictured)

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

Procedure Used

1. We lifted the car off the ground - enough for us to easily work inside the rear wheel wells. We used a QuickJack along with a few jack stands to be on the safe side while under the car.
2. Next, we pulled out the wheel lock tool out of the front trunk.
3. Using the 19 mm socket (the wheel lock tool on the corresponding bolt) and DeWALT 1/2" impact wrench we removed the wheel lug bolts on the rear wheel. TIP: we put a few wraps of blue painters tape around the outside of the 19 mm socket to prevent scratching the wheel.

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

4. With the wheel bolts removed, we removed the rear wheel while using the Porsche wheel guides to prevent ruining the wheels, brake calipers, and/or brake rotors.
5. Moving inside the rear wheel well towards the side of the engine, we removed the two E10 torx bolts to free the heat shield.
6. Next, we completely removed the heat shield. It took a decent amount of finesse to get it out of the tight space.
7. We repeated Step 2. through Step 6. for each side of the car.

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

8. With the heat shield removed, the three coils were completely visible.
PDCC Option: For cars with the PDCC suspension option, there are components that obstruct the ability to get to the left, front spark plug. To make enough room, we loosened the 10 mm bolt holding the bracket in place. We only loosened it enough to be able to use extensions and a universal joint to access the T30 Torx bolt and spark plug.

9. The tab on the electrical connector to the coil-on-plug assembly was depressed, while wiggling to free the connector from the coil.
10. Using a T30 (Torx) socket, various extensions and a universal joint, and the 3/8" ratchet, we remove the T30 torx bolt holding the coil in place. To speed things up, sometimes we used the Milwaukee 3/8" powered ratchet to remove the bolts.

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

11. Next, we pulled coils out. There is a 3 layer silicon dust seal, so it took a bit of wiggling to remove this from the engine.
12. Using a 16 mm spark plug socket, various extensions and a universal joint, and a 3/8" ratchet, we loosened and removed the spark plug.
13. With the spark plug removed, we inspected the it for excessive wear or other abnormalities that can indicate the health of the engine.
14. The new spark plug was installed by placing it in the 16 mm spark plug socket, attached an extension, and hand threaded into the engine. Porsche specifically states NOT to use any anti-seize on the threads.
15. Using a 3/8" drive torque wrench, we tightened the spark plug to 21 lbs ∙ ft. Do not over tighten!!!. Although not good practice, you will have to use an extension with the torque wrench. We made sure to hold the 3/8" drive torque wrench with both hands to keep it in line with the spark plug.

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

16. Next, we reinstalled the coil by fully pushing it into the engine, while insuring the hole for the securing bolt aligns properly. We hand tightened the T30 torx bolt and did a light tighten with a T30 (Torx) socket and 3/8" ratchet.
17. We then reconnected the electrical connector to the coil by pressing them together. We made sure that they were fully and securely connected, by giving a light tug that they didn't move.
18. Step 8. through Step 17. was repeated for each of the six spark plugs.
19. With all of the spark plugs replaced, we reinstalled the heat shields on each side and securing them with the two E10 torx bolts. We hand tightened and then lightly tightened with a E30 (External Torx) socket and 3/8" ratchet.
20. Finally, we reinstalled the wheels by repeating Steps 2. through 4. in reverse order. With the wheels installed, we used the 1/2" drive torque wrench and 19 mm socket to tighten each wheel lug bolt to 118 lbs ∙ ft. NOTE: After the next drive, we checked the torque of each of the wheel lug bolts again.

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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Overview

Parts Used

Tools Used

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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Procedure Used

Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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Porsche 911 (991.1)

Porshce 911 (991.1) Spark Plugs Change Guide

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