Hey FTE. Happy New Year! Stay safe on the roads. Remember, all the drunks will be out.

Kind of a strange question today. I know all motor vehicles will run better warm. My question to you is, how much better? Do you notice a difference in performace? None? A lot?

My truck feels like it has no low end power when it's cold. Even the exhaust sounds different. When cold, it's quiet and unimpressive at idle and sounds more buzzy under load. When warmed up, it has that V8 burble [at idle] and sounds much deeper under load.

Once the truck really warms up the power comes back.

I'm not concerned by this, merely curious. I know this is normal but I'm wanting you guys to pitch in and just tell me how your truck feels going from cold to warm / hot.

Oh yes, just a side note.. I suspected maybe I had an exhaust leak causing performance loss. I thought maybe once the piping heats up the crack swells shut. If this were the case, wouldn't I hear a leak, like a flutter?

Thanks a lot FTE. Don't get too drunk tonight!

-Bill

 

HAPPY NEW YEAR to u too.... i cant tell a great difference but their is one .... of course i still have the quiet muffler on it.... lol well semi quiet it seems to be gettting a gew holes in it..... thinking about putting a glass pack on it for the time being....

 

Okay thanks a lot Hitokori I appreciate your feedback. =) You should really put your name in your sig so I can call you something. lol

Off topic, but glass packs are the way to go. These engines sound good with one cat and a short pack.

Anyway, back on topic!

 

I always warm my truck up. It runs better and has better response. I give it until the iac kicks down in the warm months. It's definitely more snappy when hauling my quad after a few minutes on the road.
In the winter depending on how cold it is, I give it 10-20 minutes. Something just feels off if I drive it without letting it warm up a bit. Then at least the interior is warm enough that should the windows fog up, they wont freeze.

 

The only way I can tell if mine is or is not warmed up is by how warm the air is coming out of the heater.. Runs the same HOT or COLD!!!
I give mine time to get the oil pressure up, (10 to 15 seconds) then drop it in gear and go....

 

These trucks will always run "better" warm, because they enter closed-loop mode after they reach the appropriate temps.

Cold, the computers run the engines rich.

I've got a bit of a gummed up IAC, so when it's really, really cold, it'll stumble a bit on throttle tip-in. Cold transmissions really bog you down, as well.

Start the truck, give it a second and tap the throttle to idle it down. No more that two minutes should be needed before you're good to go, and that's on a crazy cold day.

 

Hey Virto

What's a cold transmission got to do with anything? I know my automatic hates to go into gear when it's cold.

 

I always let mine idle until it comes off of fast idle, even when its hot outside. I figure its better and has to be better for the transmission.

Mine definitely runs better after its about half way warmed up. It runs the best completely warm.

When its cold and its freezing outside, it is really noticable.

 

Mine seems to run sort of the same, drive for about 5-10 minutes and it feels a little smoother.

For what it's worth, *most* higher-end drag race teams set their car up on jackstands in the pit areas and let the motor run and also run the car through the gears for a few minutes + the short drive from the pits to the staging lanes to make sure all the fluids come up to normal operating temp.

 

my truck really cackles the exhaust(long tube headers,no cat,cherry bomb extreme) when it is cold started,and feels a little more responsive when the engine is cold. Wish I could find a muffler that sounded that way all the time!! Exhaust note mellows a little when it warms up.

 

Can't say there is any difference in my F-150, but I do let it warm up before I get on it.

In our Ranger on the other hand... There is certainly a difference. When cold if you hit the gas it falls flat on it's face, even half throttle will do it. When warm it still falls flat on its face but nowhere near as bad.

 

ECm plays with stuff a lot during the warmup cycle, most noticeably:

IAC counts increase, resulting in higher idle speed.
Timing advance increases, this accounts for most of the exhaust "tone"
Engine is run rich, and no input from the O2 until closed loop, this is the "crackle" in the exhaust.

If your engine bogs cold, you most likely have a problem that is exacerbated by the ECM, you might be running rich, or with too much timing. When hot, you wont notice it.

Also, I have seen cars that had temperature related vacuum leaks. Especially in the intake manifold or throttle body gaskets. Aluminum expands when it is heated, which can compress leaking gaskets "fixing" the leak, especially if you still have the silly TB "coolant" system hooked up.

 

well i dont drive my '91 f250 daily, but when i have to move it or somthing it def lets you know it wants to warm up. everything kinda works in slow motion. when its really cold (0 to -30) even if the truck is warm the axles are cold and the speedo goes crazy. when i'm going say 30mph it shows 60mph. once the axles warm up it goes away.

but seeing as how i normaly just use it to plow snow in the winter i let it warm up for about 30 mins well brushing the snow off..ect

 

Thanks for the information and feedback, fellas. I appreciate it.

 

I usually start the truck and drive off once the oil pressue is up. On a real cold day (below 10 F) I'll let it idle for a minute or two. For the first few miles I drive real easy and it wams up pretty quick. My engine seems to run well hot or cold.

Happy New Year to all
rikard