Warm up?

[Derision]

Here's a stupid question that just occurred to me.

I can remember back when I had my old Caprice Classic. I would get up in the morning before work, start the car, then come inside. With the car running, I would grab breakfast, shower, and then run out. The car was all toasty warm and great and away I'd drive to work. That car stayed running most of the day, as well... ten hours a day, five days a week, that old 350 pulled it's weight and then some.

I was thinking about that car this morning. I started my poopy Cougar and tossed it into gear, and I realized that, when it came to carbed cars, I have ALWAYS started the car, let it idle until it warmed up, and then drove away. I never did it for the fuel injected variety, and I'm not sure why.

When my Grand Prix got it's V8 five years ago, I stopped doing it. I read somewhere that letting it idle for that extended period of time wasn't good because the oil didn't get to completely circulate... and so, with my GP, I start it up, throw it in gear and away I go.

The thing that gets me though is that the Grand Prix idles high when it's cold. I mean, this car can hit 50mph without touching the gas until it kicks down. When you put it in gear, it feels like you've just been rear-ended by an Atlas V rocket. Though the TH350 is a tough little transmission, that kind of clunking-forward-lurch can't possibly be good. It's almost like doing a neutral drop. I had transmission work done maybe two and a half years ago, and the transmission guy actually complimented me on the shape of my trans... but, again, that was two and a half years back.

So I was wondering... what's the consensus here? Do you guys let your car warm up before you drive it, or do you just start it and go? And do you think the wear on the trans is negligible?

 

[85 Cutlass Brougham]

I usually let my cars come off of fast idle before moving them. In my EFI truck, it has an odd idle management system that works similarly to a choke in that it runs a higher idle speed until warm coolant melts a wax pellet and lets it come down. I usually wait until it comes off that idle speed a little before I move it, just to give the oil a chance to circulate.

On some carbs you can adjust the high idle speed with a set screw. Maybe you need to play with yours a bit and get it lower.

 

[megaladon6]

on my g-body i give it about a minute to get things moving but she doesn't like extended cold idle. she wants to drive damnit! on my VW i just make sure i have oil pressure and go. but that's a turbocharged car, you never want to idle them for an extended time because it kills the turbo oil seal.

 

[PILOT]

I let my Regal (Q-jet) sit in fast idle for about 2 minutes then give it some gas and kick it down for another 30 seconds or so, then stick it in gear.

In the winter, I let my Cavalier warm up for about 4-5 minutes. I basically go out, start it up, scrape the ice off, go inside, grab my lunch, go out and drive it. All the while my interior heat is on cold, and fan off. I freeze most of the way to work (15 min drive) until the engine temp gets up, then I crank on the heat.

 

[HAYWIRE]

Car starters are used lots up here in the winter both my vehicles are set up to run 15 minutes.

 

[dan2286]

I always let mine warm up at least a few minutes before I drive. I always figured the oil is designed to work at operating temp, so maybe it has better protection when a warmed up a little. I have no idea if that is true, but oh well. I do know that any car, whether carb or f/i, will use more gas when cold. It is trying to warm up the car faster by richening the fuel mixture till a certain temp. Its supposed to reduce emissions, dont know if that helps the engine out at all. Also I am not sure if that is the same purpose for the fast idle.

 

[HFX]

I always let mine warm up at least a few minutes before I drive. I always figured the oil is designed to work at operating temp, so maybe it has better protection when a warmed up a little. I have no idea if that is true, but oh well. I do know that any car, whether carb or f/i, will use more gas when cold. It is trying to warm up the car faster by richening the fuel mixture till a certain temp. Its supposed to reduce emissions, dont know if that helps the engine out at all. Also I am not sure if that is the same purpose for the fast idle.

Enriching actually leads to a cooler combustion chamber and thus would slow down the warmup of the car. It enriches the mixture during warm up to help smooth out the engine because the fuel won't burn as easily when cold. This would lead to a rough idle and stalling. Fast idle is basically used to keep the RPM up during this time period to make sure that the fuel that is vaporized doesn't have as much chance to condense and thus lead to a misfire and subsequent stall. If you question the unburnt fuel, realize your rpm will often rise 300-400 rpm while in fast idle from starting to warming up.

Oil flows better when it is warm, which depending on how your oil passageways are can help get oil to the bearings better when a load is put on it. On the other hand, the thick cold oil will allow the bearings to float more over the surface. As long as your oil and engine is good though, it shouldn't really matter either way.

Fast idle I believe is around 1100-1300 rpm for most gm small blocks. If yours is above this you probably need to adjust the fast idle on your car or figure out if something else is causing it to be higher. I often will put it in gear during this time

If you want experience about the transmission, my TH-200C lasted 120K before the reverse gear went out due to a boot on one of the clutch engagement pistons developing a tear.

 

[dan2286]

I always let mine warm up at least a few minutes before I drive. I always figured the oil is designed to work at operating temp, so maybe it has better protection when a warmed up a little. I have no idea if that is true, but oh well. I do know that any car, whether carb or f/i, will use more gas when cold. It is trying to warm up the car faster by richening the fuel mixture till a certain temp. Its supposed to reduce emissions, dont know if that helps the engine out at all. Also I am not sure if that is the same purpose for the fast idle.

Enriching actually leads to a cooler combustion chamber and thus would slow down the warmup of the car. It enriches the mixture during warm up to help smooth out the engine because the fuel won't burn as easily when cold. This would lead to a rough idle and stalling. Fast idle is basically used to keep the RPM up during this time period to make sure that the fuel that is vaporized doesn't have as much chance to condense and thus lead to a misfire and subsequent stall. If you question the unburnt fuel, realize your rpm will often rise 300-400 rpm while in fast idle from starting to warming up.

Oil flows better when it is warm, which depending on how your oil passageways are can help get oil to the bearings better when a load is put on it. On the other hand, the thick cold oil will allow the bearings to float more over the surface. As long as your oil and engine is good though, it shouldn't really matter either way.

Fast idle I believe is around 1100-1300 rpm for most gm small blocks. If yours is above this you probably need to adjust the fast idle on your car or figure out if something else is causing it to be higher. I often will put it in gear during this time

If you want experience about the transmission, my TH-200C lasted 120K before the reverse gear went out due to a boot on one of the clutch engagement pistons developing a tear.

Could I have been thinking it warms up the cat faster??? Then the cat operates more efficiently. I forgot about the fuel vaporiziation part.

 

[HFX]

Could I have been thinking it warms up the cat faster??? Then the cat operates more efficiently. I forgot about the fuel vaporiziation part.

It should indeed warm up the cat faster once the cat gets at a temperature to start burning the unburned fuel.

 

[Coveted]

Lego's, you go play with them.