So it has been pretty cold lately. In the morning when I first crank the car up and it isn't warmed up yet it feels like the car is shivering. The vibrations are coming from the engine during idle. Once the engine starts warming up (2-3 minutes after start up) the vibrations stop.

Does everyone's car do the same thing? Is it supposed to do that?

 

That's normal the engine is misfiring for the first couple of minutes on purpose.(emissions)

 

What purpose does this serve as far as emissions in concerned? Caused by the computer then?

 

This is normal with all Honda V6's engines. The colder it is outside the longer it takes for your engine to warm up when you 1st turn the engine over. In the summer this process is much quicker!

 

Completely normal and expected. As long as it smooths out once the car is warm it's fine. Cold running has historically been when cars "spew" the most pollutants. Some say older cars spewed more the first five minutes of cold running than they did during the next hours of warm use. Not sure if that's true but what is true is that the engine control in the TL runs the car very rough (presumably leaner to warm the engine quicker so it can run cleaner) until warmed up in an effort to reduce total overall emissions. Note that ULEV sticker on the car.

 

oh. You mean the ulev sticker I took off when I got my windows tinted? Ok. Well then maybe I'll just start waiting for my car to warm up from now on.

 

You should always wait for your car to warm up before driving it. I have since my car was brand new.

 

It misfires to dump raw fuel into the cats to light them off quicker. Raw fuel chemically reacts to make heat.

 

Interesting. That would seem to imply it's "spewing" more unburned hydrocarbons than I thought during the initial warm up. I also thought that raw fuel and/or overly rich was about the worst thing you can do to a cat. Maybe that's only if it's for a prolonged time, which this isn't. You sure about it?


Debatable. There is no need to let it sit there idling for 5 minutes or so until the temp gauge comes up, if that's what you mean. That's just wasteful and a throwback to days of old. Start it up and by the time you've buckled your seat belt and picked a radio station (like 15-30 seconds) you are good to go as long as you aren't racing. Drive modestly until it's warmed up and then do whatever you choose.

 

It's very bad for the cat for extended periods because it will cause overheating. But it's great for getting it up to temp quickly when it's cold.

 

you should here a really cold start with pre-cat deletes - like a bag of nickles running down the pipes (not really that bad, but will make your wife give you the "WTF?" face).

i guess there's merit to saying modern ECU's won't let you do damage driving off with a cold engine but, I still let mine run until it idles smooth before jetting. Call me old fashioned.

 

To tell you the truth, I have a feeling some of that fuel ignites in the exhaust and more than likely the timing is retarded which also makes it louder.

I agree to let it warm up somewhat. Most clearances don't change much from cold to hot but the piston to wall changes a lot. It's good to get some heat in the pistons before putting it under load. My GN has piston slap when cold for the first minute due to the large clearances required. You can hear with your ears the pistons rocking in the cylinders and you can hear as it gradually goes away as the pistons expand. After hearing that I can't let myself drive the TL for at least 45 seconds. The majority of the cylinder and ring wear is during the warmup process.

On flip side you want the engine to get up to temp as quickly as possible to avoid this wear. My drive to work is a steady state 45mph for 5 miles so I start, idle for 45 seconds and go. A steady speed is a great way to warm the engine up gently but quickly.


The oil is still thick and the pump and filter will go into bypass if the rpms go too high too soon. It's not the end of the world but if you have the option to avoid it, it's not a bad idea.

Keep in mind that while the water hits full temp in a couple minutes, the oil can take 15 minutes to hit full temp. If I'm in a hurry to get to work I'll gradually ramp the power up but no WOT for 10 minutes if I can avoid it.

Old carbureted engines forced you to warm up the engine or it would stall. With fuel injection it won't stall when cold so many don't warm it up but it's still a good idea to drive it nicely for the first few miles.

Again not much of a problem with Fuel injected cars but in the old cars you got cylinder washdown from a rich cold idle mixture with the choke on where the fuel washed the oil off the cylinders. Cars that were idled excessively showed more wear. With the TL, it's in closed loop feedback so quickly that there's hardly any enrichment time to hurt anything but it's something to keep in mind.