97 Q45t spark plugs

[tangywaffle]

I am almost certain that this has been posted before, but where is a how to for replacing my spark plugs in a 97 Q45t? I've searched, but I cannot find more information. Can someone please help me? Thanks so very much!

[elwesso]

plug job on a Y33 is basically the same as the G50, except you have less stuff to remove.. Simply remove the coils and the plug is right underneath it.. once you get in there, its simple as cake.

Ill let the Y33 owners point you to a specific thread, im sure someone has pictures out there somewhere..

[BadQ45t]

If your not a good DIY'er you might be better off to take it to a mechanic that has done a plug job before, there is a decent amount of stuff to take off before you get in there.

Also remember don't use any Bosch or other plugs, strickly NGK OEM, these cars just don't like other brands at all.

[Q45tech]

Incompetent plug changers can do serious damage [cause intermittents and misfires] to the coils by pulling them off plugs too hard and too fast.

[QFourFive]

Incompetent plug changers can do serious damage [cause intermittents and misfires] to the coils by pulling them off plugs too hard and too fast.

How exactly do the coils get damaged? Could you see physical damage or would you just be able to tell from the effects?

[BadQ45t]

As I recall you have to physically move them out of the way to get to the plugs, so there are lots of bad things that an incompetent DIY'er could do to themselves.

This is best left to a pro unless your a pretty smart DIY'er that knows knows how to work on newer cars.

[oldmako]

It's not rocket science nor overly difficult to replace the plugs on a Q41.

Each coil is held in place with two 10mm bolts. Each coil has a plastic connector which mates up with the wiring harness. To my mind, the harness is the weak link and the most likely thing to get one into trouble.

Once the harness connector is gently removed, take out the two bolts and carefully lift the coil straight out. It has a 4 inch plastic tube which protrudes out it's backside which slips over the tip of the plug after it has been threaded into the head. Use care when handling the coil and you ought to be OK. It's fairly sturdy, but not something you want to toss around. They are quite expensive. Now, the coil might be on it's deathbed and simply jostling it around might kill it....who knows. The newest one on the road today is already 8 years old. They live in a hot spot.

There is a clylindrical recess machined into the head where the plug lives, and in that recess is where the coil mates up with the plug. Keep dirt out of this recess as it has but one place to go when the plug is removed, and that place ain't good for foreign objects, debris, flotsam, crud, shinola, detritus, effluent, talus, etc.

Have a goodly supply of socket extensions and adapters. Install a second elbow if possible. Use anti-seize. Take your time and it's a two- two and a half hour job. Hustle and do it in an hour to 90 minutes. Two, maybe three beers. Four if you're a spirited wrencher. Both hands will be busy so skip the Cohiba.

Take a gander at the FSM before you delve in and save yourself a coupla hundred bucks.

[QFourFive]

Oh ok, I'm good then. I was experiencing bad engine performance (low idle/ stutter while accelerating) a couple of days after changing my plugs. I went back and did a very careful check of every one and everything was fine but the engine was still acting up. I think it just doesn't like the plugs I used, The NGK Iridium IX. I checked the service manual and they recommend the Premium Platinum NGK. I will install the Premium Platinums on Wednesday and see if my problems clear up.

[oldmako]

It appears as though the coil packs are the weak link in these cars as the injectors are in the older models. It's entirely possible that you messed one or more of them up, but the stumble could also be caused by something else. If it began after you changed the plugs then the coils and plugs are a great place to look first. I used the factory plugs when I did mine and have had excellent results for the last 50,000 miles.

Search some of the old posts and you'll get an idea as to what others have done to smooth out their engine. Knock sensors are another likely culprit. Read Andy's posts.