Replacing spark plugs and coils on Mazda Tribute V6

Here are DIY step by step instructions for replacing the spark plugs and / or coils in a Mazda Tribute V6 (based on a 2001 Tribute).

This is a lengthy procedure, but don't be frightened, it works...I have done it a few times. This will save you a few hundred $$$ if you do it yourself. Make sure to read all of these instructions, preferably while looking at your engine, before you get started. You will need 2-3 hours to do this job.

NOTE 1: IF YOU HAVE A SPECIFIC ISSUE WITH CYLINDERS/COILS 4, 5, OR 6, YOU ARE IN LUCK, YOU ONLY HAVE TO REMOVE A PLASTIC ENGINE COVER. IF YOUR ISSUE IS WITH CYLINDERS/COILS 1, 2 OR 3, OR YOU ARE CHANGING ALL OF THE SPARK PLUGS, YOU WILL HAVE TO REMOVE THE INTAKE MANIFOLD. THESE INSTRUCTIONS COVER CHANGING ALL OF THE SPARK PLUGS AND CAN BE USED TO REPLACE ANY OF THE COILS.

NOTE 2: IF YOU ARE THINKING OF REPLACING YOUR SPARKPLUGS BECAUSE YOUR ENGINE IS RUNNING ROUGH, PLEASE DO YOURSELF A FAVOR AND GET THE ENGINE SCANNED FIRST TO MAKE SURE THAT A COIL IS NOT THE ISSUE. YOU CAN REPLACE YOUR PLUGS AND BAD COILS AT THE SAME TIME WITH THIS PROCEDURE. YOU WILL BE UPSET IF YOU DO THIS WORK TO REPLACE ONLY YOUR SPARKPLUGS, THEN YOU FIND OUT AFTERWARDS THAT A COIL WAS BAD AND YOU HAVE TO DO IT AGAIN LIKE I DID.

1. Tools: Pliers, ratchet wrench, ratchet wrench socket extension, 8 mm socket, 10 mm socket, Spark plug socket, flat head screw driver, plastic zip tie, plastic cup or bowl. Not necessary, but very helpful: Magnet on an antenna to pick up dropped nuts/bolts.

2. All directions are given from a point of reference as if standing in front of the car, except for removing the coils and plugs from firewall (back) side of the engine.

3. Using flat head screwdriver, loosen band clamp on large rubber air intake hose where it connects to the intake manifold on the right side of the engine. Slowly work rubber intake hose off of intake manifold.

4. Unplug wires from back side of air idler valve - small unpainted metal part mounted on top of air intake on manifold (close to where the air intake hose connects to intake manifold).

5. Disconnect small rubber hose from top of the ERG valve (black metal disk near back right side of manifold.

6. Remove the two bolts that hold ERG valve to manifold bracket. Use the 10 mm socket and ratchet to remove these. If you are trying to remove the 8 mm bolts, you are removing the wrong bracket. Be careful, there is a gasket between the manifold and the ERG valve, make sure it does not fall out when removing bolts. Place bolts and gasket in cup.

7. There is a small plastic sensor just to the left of the ERG valve towards the back of the engine. If you look at how the sensor is attached to the manifold, you will see that the back left side bolt that holds this sensor, also connects the intake manifold to a plastic wiring harness at the firewall. You will need to remove the 8 mm nut from this bolt to free up the intake manifold in a later step. Now remove 8 mm bolt from other side of sensor. Might need the socket extension to remove these. Place nut and bolt in cup.

8. Unplug wires from the back of the sensor discussed in the previous step (7).

9. There are 3 hoses of different sizes plugged into the back of the manifold. Unplug all three hoses from manifold. Remove zip ties if needed to slide hoses off. Left hose may have a compression clamp, use pliers to loosen clamp while sliding hose off.

10 There are two large black plastic wiring connectors supported by the back left side of the manifold. They are supported by plastic clips with plastic barbs. Use the flat head screw driver to pry off the support clips from the manifold - don't worry, you won't break them. You will be able to plug them back in later.

11. There are still a few things attached to the intake manifold, but there will be enough flexibility now to lift up the manifold and replace the spark plugs.

12. Remove the plastic engine cover - there are three 8 mm nuts to remove. You will need the socket extension. One the nuts are removed, you will have to wiggle the cover off especially on right side. Place nuts in cup.

13. The plastic intake manifold on top of the engine is now exposed. If you look down at the front side of the engine, you will see the coils for cylinders 4, 5 and 6 (going from left to right). The tops of the coils will probably say "Motorcraft" on them. Also, there are two cables attached to the top of the manifold - leave them alone.

14. There are 8 bolts that hold the intake manifold down. The bolts are located in two rows of 4 across the top of the manifold. Loosen them all using the 8 mm socket with extension. Note: these bolts do not come completely out when fully loosened.

15. Slowly work the intake manifold loose by lifting up on each side. NOTE: Work the manifold off of the bolt discussed in step 7 (back right side of manifold), NOTE: Work slowly watching for anything that might be hanging up. You should eventually be able to get about 4" of clearance between the back right side of the manifold and engine, and 8-10" of clearance on the back left side. Move around to the passenger side to help lift off the manifold. While working on the back side plugs, you will stand on the passenger side of the car.

16. Once you are able to lift up the manifold, get a cup, block of wood, anything suitable approx. 5" tall to prop up the manifold (place under center of manifold). This will keep the manifold off your hands while you are working.

17. The three coils on the back side of the engine are now visible if you are standing on the passenger side of the car (cylinders 1, 2 and 3) Cylinder 1 is closest to you - passenger side, cylinder 3 is furthest from you - driver side.

18. Each coil has one 8 mm bolt holding it down. Take the 8 mm socket and ratchet and remove the bolts from the 3 coils on the back side of the engine. Place bolts in cup.

19. Lift each coil away from engine (do not pull on wires plugged into the coil). Pull each coil's silicon rubber tube out of spark plug hole, bend tube to get it out without pulling on the coil wiring. Leave coils plugged in and lay them to the side. NOTE: If you are looking to replace a coil (or coils) simply unplug the coil wires from the old coil, and plug into new coil at this stage.

20. Using sparkplug socket and socket extension, remove each of the back 3 spark plugs.

21. Install the new spark plugs (gap them first if they are gap type).

22. Slide each coil rubber tube back into sparkplug hole and bolt down coil (8 mm bolt). Congratulations! The hard part is over with!

23. Make sure the rectangular intake port gaskets are clean on the engine (before lowering the intake manifold back down).

24. Slowly work the intake manifold back down to the top of the engine - make sure that the manifold is back on the bold discussed in step 7, and that nothing is binding.

25. Bolt the manifold back down (eight bolts, 8 mm, still attached to the manifold). Use 8 mm socket with extension. Gradually tighten the bolts going from bolt to bolt until they are all tight (don't fully tighten one bolt first).

26. Remove coils and spark plugs on front side of engine. Replace spark plugs and re-install coils. Same procedure as back side of engine, but much easier. Replace coil(s) if desired.

27. Re-install the two plastic wiring connector support clips to the left side of the manifold - push barbed clips into manifold.

28. Reconnect 3 hoses to back side of manifold. Place new plastic zip tie on hose that had zip tie.

29. Reinstall plastic sensor on back right side of manifold (8 mm nut and 8 mm bolt).

30. Plug in wires back into back side of plastic sensor.

31. Reinstall 10 mm bolts and gasket on ERG valve and tighten to manifold.

32. Reconnect small rubber hose to top of ERG valve.

33. Reconnect large air intake hose to intake manifold and tighten hose clamp using flathead screwdriver.

34. Plug wires back into back of idle air control valve (this was uplugged in step 4).

35. Leave the plastic engine cover off for now. Check all around the manifold and make sure everything is reconnected.

36. Start engine - should start and run normally (or better). If not, go to trouble shooting at the end.

37. Reinstall plastic engine cover (three 8 mm nuts). Make sure engine is not running when reinstalling plastic cover.

TROUBLE SHOOTING: If engine light comes on (and wasn't on before changing plugs), or if engine runs rough, stop engine and double check that all wires and hoses are plugged back in. If you find wires or hose left disconnected, reconnect them. Disconnect car battery for a few minutes then reconnect (to clear out engine alarm). Restart car, engine should run well, engine light should be cleared.