Warming up the engine....

Hi there,

How important is it to warm up your engine first thing in the morning?.

Does it increase the life time of the engine or some such?.

Just curious.

Pravin Nair.

 

I run it for 30 sec or so, then drive slow for the first couple of miles
(until I get to the freeway)

 

It is best to let the car idle for a few seconds to make sure everything is
lubricated, and then just take it easy until the car warms up completely.
No reason to just sit there and waste gas while it warms up. Also it is
possible that the extreme rich running condition of a cold engine could
cause cylinder lubrication problems, so you'd be better off driving the car
so that it will warm up quicker.

 

by letting it idle to warm up you actually cut your engine's life. Start it,
count to 10, then drive. Be very easy on the car (eg NO speeds over 45 mph).
as soon as your coolant temp gauge raises to its middle point (or close to
it), drive it as you would drive it normally with no ;-))) caution.

eraser

 

Not to mention you will have to replace your muffler and pipe every 2
years if you spend too much time warming up. All the moisture
collected inside by condensation while the car sitting warming up in
cold weather will cause them to rust from the inside.

 

It's not good for modern cars. They less time they're idling cold, the
better. That's when they're running dirty, having poor fit between
moving parts, collecting combustion contaminates in the oil, and not
getting good oil circulation.

Give the engine enough time to stabilize, about 3 to 20 seconds, then
drive it gently. Avoid cold RPMs near redline because the oil may be
too thick to spread over the metal surfaces at that speed. Of course
it's best to not drive your car into a ditch because the windshield is
frosted over, but don't idle it warm without a need.

Check your manual for details.

 

I have to disagree with just about every response.

First, some credentials...I was a 12 year certified technician, and
regularly did engine rebuilds on both gas and diesel engines. As a fleet
manager, will also did extensive wear studies and regular in-depth oil
analysis. While I am no longer "in the field" I still get my hands dirty
building hi-performance engines for boats as a hobby.

With that said...I will make this blanket statement...

"Allowing the engine coolant to reach its maximum operating temperature at
idle after a cold start, will extend the life of the engine."

Think about it...20 degree block, and your going to drive away after 30
seconds!? Tolerances are too tight in a cold engine for loading
purposes...you are "shaving" longevity away from your engine. We have done
those precise studies in our fleet, and that is our findings. My very own
'94 Accord with 138k miles on it, has *always* been completely warmed up,
and to this day, runs like its brand new.

Talk about rusting your exhaust system by letting your car warm up, is
nonsense as well. That doesn't even make sense.

I welcome any debate on the subject, and I sure there is good rational for
those who disagree, but we actually did the studies, and tore down the
engines afterwards. Believe me...seeing, is believing.

Take care.

 

http://home.insight.rr.com/cgreen/

[snip]

Modern engines that are properly tuned do not run "rich" when cold. They may
be running "richer" than normal conditions, but not overly so.

Today's modern engines are designed to burn ALL the full at any given
temperature range. If your modern engine is having fuel wash at ANY time,
there is something wrong.

Take care.

 

Netsock,

Have you done any testing with regard to systems like the PreLuber?

It'd be interesting to compare an engine on PreLuber and an engine that
simply warms up to operating temperature.

 

Oh, yeah, btw:

http://cartalk.cars.com/Columns/Archive/1996/January/01.html

http://cartalk.cars.com/Columns/Archive/1994/November/18.html

 

You're cracked. How long would that take? 10 minutes? It's a
machine. Drive it.

 

So you are saying that a car that is overnight cold in the middle of winter
would have the exact same emissions percentages of a car that is fully
warmed up? That's just not true.

 

No...thats not what I said.

--
'03 S2000
'94 Accord

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

 

Very good question!

We did do some analyst on boats, and found it to make quite a difference on
wear.

"Dry run" is when your engine is turning, but oil pressure has not
stabilized. This *IS* the worst time for any piston engine. It, of course is
worse in cold weather, but we found the biggest engine killer to be...get
this...over servicing.

Ever notice that you oil light stays on an extra 3 to 6 seconds after you
change your oil? Well, that is "dry run". The engine is running, and you
have none to low oil pressure...not a good thing.

So if you were to change your oil every 2k...think about it...after 40k, you
would have over 1 to 2 minutes of running your engine with no oil pressure!

Filling your filter before installation can help, but not all filters are
mounted vertically.

Oil companies and engine manufacturers want you to change your oil every 3k.
Our oil analysis showed that we were throwing away a *LOT* of good oil on an
average commuter engine. We found that 4500-5000 miles was better serving
point in that environment.

Don't get me wrong...there ARE applications to change every 3 k, but the
average passenger car doesn't need it that often.

Back to the pre-luber...a GREAT idea...works as it should...we get a full
extra summer season out of our 425hp 460 cid jetboat, however, I cant
recommend it for low load (average commuter) car...its just not worth the
cost. Simply by changing drivers habits and servicing, its easy to get 200k
out of an engine nowadays. By that time, other aspects of the car are in
issue, but with a work horse (truck, towing, boat, hauling, hi-performance)
I would HIGHLY recommend it.

Take care.

--
'03 S2000
'94 Accord

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

 

Tom and Ray (to whom I've never heard of) seem to be good ol' boys and well
intentioned, but I didn't catch their credentials. Nor did they give any
real explanation to their methods.

Like I said, to each there own...but Ill stick with real world facts to make
my judgments.

Take care.

--
'03 S2000
'94 Accord

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

 

Only on Saturday nights.

It depends.

My Accord gets into the "operating" range after about 4 minutes @ 32 F.

You can drive it, or drive it into the ground...which ever you prefer.

Take care.

--
'03 S2000
'94 Accord

It's just about going fast...that's all...

http://home.insight.rr.com/cgreen/

 

If it burning ALL the fuel at any point, the emissions would be the same at
any point. Heck, cars wouldn't even need a catalyst if they could do what
you are saying.

 

No they wouldn't. RPMs are a HUGE factor.

Catalyst are designed to deal with the nitrous by products from burning fuel
(gasoline). The catalytic converter has little to do with unburnt fuel.

I will however clarify...modern engines are designed to burn 97% of the fuel
at any temperature. The remaining 3% could never result in "washing" of the
cylinders...which was my point.

 

So how long does it take for one of those diesel engines to warm up
at idle in cold weather?

Big deal. Lots of people have cars with more mileage and no problems
without doing any idle warm-up.

 

Big deal. Lots of people have cars with more mileage and no problems
without doing any idle warm-up.[/QUOTE]

In fact, my 120K mile 92 Civic, with 3K mile oil change intervals and
minimal warmup times, showed an oil analysis where the engine was in
brand-new shape. And it continues to run.