Shaking idle
 

I noticed soon after I baught my truck that when I'm in park sometimes it seems to shake a little but it's smooth any other time. Might it be time for a tune up?

Interesting you mentioned this, as my 2005 4.2 developed an "infrequent" stumble at idle recently. When I bought this truck used about two years ago, it had 71K (not even broke in for me!), I performed some maintenance on it, as I never trust what was done unless there are receipts to prove the work. After the trans flush, radiator flush, rear end fluid change, I also changed the plugs and belt. A year and a half later, I'm getting the stumbling idle; not often, but enough to raise my attention. I bought a set of plug wires and a new coil pack (the V6's use one coil pack). I plan to do this work this weekend.

I suspect I have a plug wire going bad; changing the coil pack is just insurance for me. At it's current mileage of 74k, I'm sure the plug wires at the very least are in need of replacement. Next on my list will be the O2 sensors; not that I expect them to be the cause of this infrequent idle stumble, but rather to help grab a bit more in the MPG area; new O2's can help tweak that a small bit.

Where in Texas are you?

Thats the way they are designed...(what ive heard)... they start leaning out at idle..?? both my 02 and 08 does this at idle...everyone says if you get a programmer this will solve the problem...

i just got my programmer in a few weeks ago... but ive been sick for nearly a month havnt been able to get out and do stuff... so as soon as i get better this programmer will be in and i will hopefully get rid of my shakes

It did not do this for a year and a half; just recently It started. Idles, then one "burp"...like a mis-fire of one cylinder.

Interesting thought of a tuner. I have the opertunity to use a Superchips tuner for my 4.2; I don't need any "custom tunes", as the 4.2 is not going to beltch out fire from it's exhaust unit, especially since a buddy is letting me use his (he restored his stock flash back in, so the unit is not locked to his VIN). I will test this idea, but still plan to install the plug wires as well. Perhaps I'll flash the tune first, see what that does in the way of the idle, drive it a couple of days, then report back. Then install the plug wires.

when i bought my 08 i got 3 free oil changes ... and after that i started using royal purple and K&N oil filter... and i think the RP synthettic helped the vibrations also... i cant wait to see if the tuner helps it...my 08 feels like it has parkinsons sometimes

Thanks for all the info on this I could deff use it. I live in kerrville tx(sixty miles from San Antonio). I think I'm gonna deff try some new plugs and wires and look into that programmar thing.