AmorSrdanovic

hey guys, I've got an 06 S65 with 65k miles on it and sometimes when i start the car cold i get a slight to mild shake from the motor, doesn't really happen when its warm already, but it goes on for a little bit (1-3mins most) and then it stops shaking, accelerating is no issue after it gets warm it stops totally, is this spark plugs that need changing? and can i do it myself if i have to change them? thanks.

marktan

Are you throwing any misfire (or other) codes? I'm guessing something may be leaking in the secondary air injectionsystem if it goes away when warm (since it runs for a few minutes when the engine is cold). Could be transmission or engine mount I suppose as well, but since it goes away after a few minutes, that may not be the case.
I can do the plugs on my S600 myself in about 2-3 hours, but you have to be REALLY careful about handling the two coil packs when removing and re-installing. They are delicate and cost $1200-1400 each to replace. You've also got 24 spark plugs (2 per cyl). At your mileage though, I'd be suprised if the plugs are worn unless you've got some internal engine issues happening. Just my 2c.

AmorSrdanovic

no codes show up, my dad brought it to a mechanic and he said 2 cylinders weren't firing properly(3&8). since it goes away i assuming the computer was just pulling some timing out to get it to stop. any more tips on changing the plugs myself?

AmorSrdanovic

ive read online that the 65's need a plug change at around 60k miles

marktan

Since it is across both banks, perhaps it could be the plugs. If it was consistent on one bank, I'd lean towards a bad coil pack.
I've changed plugs on mine 3 times now...It's not hard if you're patient and gentle.

If you do a search on "coil pack replacement" there is a pictorial on how to get those off. Once you have them off, you can access the plugs.

My tips for what they are worth:
When removing the air boxes, watch that you don't break the nipple off the one pressure sensor that is located between the two intercoolers by the throttle control unit. It will cost you $50 for the sensor if you break it.

**Take your time** and remove the coilpacks slowly and carefully and evenly across the unit (don't pull one end out more than the other or you will hear a crack, and the circuit board inside will be toast). You have two, each spanning an entire bank of 6 cylinders. This will cost ~$1200+/ each if you break it.

As much as you will want to, don't twist or pull at the metal tubes once the unit is removed - they break off easily and if that happens, the entire unit is shot. It looks like they would be removable with a half twist, but they are not - there are three wires at the top welded directly to the circuit board. If you twist or pull, the wire or weld breaks (ask how I know about this $1200 mistake).

There are red insulating boots that seal the ignition coil tube onto the spark plug. Sometimes they come up in the tube with the coilpack (if you're lucky), sometimes they get stuck on the sparkplug. I found an offset needlenose plier works to reach and remove them if they get stuck on the plug. I've heard that you should replace them every time they are removed. I have not done this except for the two that I tore with the pliers while removing them. They are cheap at least (~$2/each) I do, however, remove them all and clean them before replacing into the coilpack with a bead of fresh dielectric grease for the new plug. No issues so far as that is concerned.

Remove and replace (don't forget to gap) the new plugs (24 total, 2 per cylinder). I've used both the stock NGK iridium, the autolite iridium, and the Autolite double platinum on my vehicle...I seriously can't tell the difference at all - other than fresh plugs always seem more peppy than old ones.

While it's off, take a look around the valve gaskets for leaks.
Don't break, kink, or pinch the vacuum tubes leading to the turbos or secondary air pump.
Invest in a magnet on an extendable rod and a "claw" to retrieve dropped bolts/sockets/tools. To that end, I also put a piece of wide packing tape over the turbo inlet as soone as I remove the air box (you REALLY don't want a bolt or socket dropping down there and getting stuck in the turbine or damaging one of the vanes).

Call the chiropractor for an appointment to get your back adjusted after all that bending over the engine bay.

If you do it properly, it should start right up.

AmorSrdanovic

thank you i really appreciate the advice

AmorSrdanovic

so i had the plugs changed and the mechanic says the coils are in good condition, the other day the car asks for oil and i put in a little less then 1.5 quarts then start the car and the check engine light comes up again. i took it to auto-zone to check it and i still have the misfire on #3, they suggested it was either the new plug burned out already or the fuel injector is bad. im probably heading to the dealer to know for sure but there prices are robbery, has anyone changed fuel injectors on an s65 and could explain it to me? or direct me to some video about it, thanks