My 04 runs(idles) very rough when cold (after sitting for more than 4hrs). It feels as though it's missfiring, but runs and idles smoothly once it warms up. I've changed the plugs, seafoamed it and cleaned the T.B. with no change. Any ideas what might be causing this?

 

From what I've heard, it's normal because of the ULEV.

 

or motor mounts.

 

+1. Probably just be the very common ans inherent ULEV startup roughness.

 

as stated, it's the ULEV system. If you feel that it is excessive, get the motor mounts checked as they are prone to getting broken/leaking

 

My vote is the EGR valve. The TL is notorious for sticky EGR valves.

 

It definitely seems excessive and can't imagine that it is supposed to be this rough. Is replacing the EGR valve a big deal? Thanks!

 

no but it costs a few $$ and its under warranty if its defective.

 

I just picked up an '04 TL last week and noticed the cold idle is pretty rough. Searching around these forums it seems a rough idle is normal when cold with the TL. Once the car is warmed up it idles and drives very smooth. I haven't changed out the plugs yet but I did SeaFoam the car two nights ago. I'm not too concerned though since it's 1) said to be normal and 2) only occurs on cold idle; runs fine once warmed up.

 

i dunno....no rough idle with mine when it starts up.... ever, even in the dead of winter.....unless my motor mounts are broken. the plugs only made a difference in mpg and ive never seafoamed it....i just clean the injectors properly and throttle body and manifold every 30k... i have the injector cleaning machine at a friends shop so it doesnt cost me anything to do it...some of us dont have that readily available. i also change all fluids on time and sometimes before times up. constant maintenance and feeling for the car thats what its about.

 

We all have different definitions of "rough" idle. My roommate didn't even notice the idle was rough when we were leaving the other night. To me, it's very noticeable and I would consider it pretty rough. My friend just picked up an 05 TL so I'll have to check his out and compare it to mine.

 

mine too couldn't idle any smoother after the first 60sec or so, but I still find it strange that it's considered normal for this type of car. It doesn't bother me one bit, but just wanted to make sure that I don't have a problem.

 

My 2005 6MT has always idled very smooth, hot or cold, I never used any cleaner, or had egr problems, or any other problems in over 30,000 miles.
It sometimes sits in the garage a long time, or gets started only to move it out of the garage which caused problems with other cars, but not the TL.

So I would think anything noticable is not normal.

My TL seems to be one smooth machine, that is its most noticable trait, smooth, smooth, smooth....at all times and speeds....

Brett