Rough idle?

My 06 Tacoma v6 seems to have a shake when in park, not in drive. The shake is not constant. Seems to fluctuate between a vibration and a shimmy. Opened engine bay, and visibly saw engine cover and oil cap shaking. 46,000 miles on it. Just wondering if this vibration is normal for the 4.0 L v-6? If not, what can be done about it? rpm's are normal as well

 

check out the "similar threads" that are located at the bottom of this thread...good starting point

 

i notice some roughness here and there...i noticed less of a roughness when i put in my new fuel pump and fuel system cleaners seem to keep the engine running fairly smooth

 

I'll look for chevron techron. Any brands to stay away from?(stp?)

Also, I'm getting new plugs, tb cleaned within next 3000 miles

 

i usually go with the lucas fuel system treatment

 

Just a thought, if the fuel injector cleaner does not solve this. Could it be caused by something more serious?

Vaccuum leak? Engine/Tranny Mounts?

I thought it may be a vaccuum leak, but wouldn't I experience a high idle speed?

and engine mounts and tranny mounts, wouldnt i experience nasty vibrations all the time?

 

The rough idle can be caused by a number of things, from a loose splug, dirty MAF, dirty airfilter, bad coil, bad gas, etc.

It might be worth it to, dare I say it? have a mechanic run a diagnostic... just find out what it is, then fix it yourself; no point in replacing perfectly funtioning items while hunting down the problem.

 

Already checked airfilter.

I'll start with the cheap repair possibilities. First thing I'll do is add a bottle of fuel injector cleaner next time I fill up the tank (probably Wednesday). If that doesn't fix it. I'll live with it till next oil change, when I'm due for new spark plugs and a throttle body cleaning anyway. If it still idles rough, I'll have a diagnostic run. But this could simply be a bad tank of gas anyway. So I won't jump to any expensive conclusions. Also, as long as it's not getting worse, I won't worry about it too much till tune up time comes.

 

Are you driving alot of dirty/dusty conditions? or is stuff staying pretty clean?

the reason I ask is because if it's dust related, that'll help narrow it down; similarly, if you're not eating dust, then that can help rule out some possibilities too.

 

Staying on road.

 

In that case I'd focus first on fuel, injectors, throttle body, coil, plugs (not necessarily in that order)

 

Yes that was my general plan. In search of a potential problem today, I just discovered how long the tacomas oil dip stick was. The thing is like 5 feet long!