High Idle, Rough Transmission Engage (both D and R), Occasional Missfire

[webby88]

Hey guys, this is my first post on this forum and I am looking for some tech and diagnostic advice for my '02 LS v6 3.0

I got the car a few years ago with around 45k miles and today it has 68k, since buying it I have changed out one coil and an alternator in response to a misfire on that cylinder (dont remember which one) and a electrical issues and have been pretty much ok since.

I say pretty much since the thing is that since the first day I got it the car would always idle pretty up there - the worst being 900-1000 rpm but usually around 800-900, and when engaging the transmission into either Drive or Reverse it kinda jerks (more like a jarring lurch) into it, but once engaged it seems that it works as it is supposed to.

Oil changes have been done every 3k regularly and since I got it the plugs have never been changed - I have no info from the previous owner.

A few days ago when it was raining and I went to start the car in the morning it felt like it was misfiring but no check engine light and when I went ahead and put the car in reverse it engaged and immediately died. Restarted, put into drive and was sort of fine for about 10 minutes then started (what felt like) misfiring and died - again no CEL. Restarted and took it back home slowly, the next day it was perfectly fine and has been since.

I am handy with tools and am ready to pull off the manifold and change out the plugs etc. but in relation to my symptoms is there anything in particular I should look out for and/or change out while I am in there? Also, what are the best recommended replacement plugs?

 

[fudge12]

Did it only die in gear? How was it running at idle? Jerking when putting into gear indicates a solenoid block problem. You could try doing a relearn process, but I doubt that'll solve anything. If it died when in gear, I'd be looking at the torque converter or maybe even a clogged filter. Could be coils too since you only changed 1. It's best to change all at once.

 

[joegr]

Change all coils and spark plugs.
Change your PCV plumbing while you have the manifold off.
You may need to clean or replace your IAC.

 

[webby88]

Did it only die in gear? How was it running at idle? Jerking when putting into gear indicates a solenoid block problem. You could try doing a relearn process, but I doubt that'll solve anything. If it died when in gear, I'd be looking at the torque converter or maybe even a clogged filter. Could be coils too since you only changed 1. It's best to change all at once.

Yes, it died in gear. It idles pretty high regularly but no stuttering or misfiring. The jerk into gear feels like maybe missing fluid, but this clogged filter thing makes sense. Any more info on how to check all this stuff out?

I changed the lone coil over two years ago and haven't had any real issues in between, so I am not so sure about it. When I change out the plugs I will go ahead and replace them all.

Change all coils and spark plugs.
Change your PCV plumbing while you have the manifold off.
You may need to clean or replace your IAC.

What type of plugs are recommended? Plain copper or anything fancier? Can you list the PCV plumbing items that is recommended I replace?

Thanks for all the replies, 'aint nothing like experience!

 

[joegr]

Yes, it died in gear. It idles pretty high regularly but no stuttering or misfiring. The jerk into gear feels like maybe missing fluid, but this clogged filter thing makes sense. Any more info on how to check all this stuff out?

I changed the lone coil over two years ago and haven't had any real issues in between, so I am not so sure about it. When I change out the plugs I will go ahead and replace them all.


What type of plugs are recommended? Plain copper or anything fancier? Can you list the PCV plumbing items that is recommended I replace?

Thanks for all the replies, 'aint nothing like experience!

Get the OEM plugs, not copper.
Replace the COPs too, this is important.
Mainly the PCV valve and the elbow at the valve, but check everything.

 

[jrand]

the misfire is caused by the coils for sure. do all of the coils, maybe the plugs too if they are bad. the one you replaced may still be good. i had more problems in the rain with coil-related misfires as well on my 05 v6. i recommend the bdw/intermotor from advance auto. buy online/pickup in store, codes A123 or ES123 will take $20 off $50, just buy each coil in seperate transactions to maximize the savings. if the codes dont work google will provide current codes (sometimes they change the letters in front of the '123' part of the code). those coils have a lifetime warranty, which the Motorcrafts and Visteons everyone here recommends do not.

inspect the pcv hose and if you suspect it is bad you should replace it at this time as others have noted. the factory clamps are not good on some models and you may just need new clamps. lincoln replaced my pcv for free due to recall on the 05's only i believe.

the gear selection issue is caused by the failing coils. your pcm keeps getting different specs and is constantly having to adapt. its not that good at adapting. so once you replace your coils (and plugs and pcv if needed) go unplug your battery which will clear all of the old shift specs and 'keep alive memory'. follow the battery reconnect procedure found in the owners manual and perform a drive cycle on the vehicle (search for that, someone posted it in september or so). run a bottle of lucas through it for good measure.

the idle figure you noted may be normal, depends how warm the car is... if its not yet up to operating temp than it is normal at the measurements noted. if that is your warm idle i would suspect the directions above would have fixed that too but if not, check the air filter, clean the MAF, clean throttle body (teflon-safe cleaner only), and clean the IAC (search for that)

 

[webby88]

Get the OEM plugs, not copper.

OEM is Platinum? Rockauto reccomends the ngks

 

[joegr]

OEM is Platinum? Rockauto reccomends the ngks

Yes, and NGK is OEM for the LS.