Feedback please

[Luca]

Can i ask 4 some feedback please...
I've had a lengthy discussion with my bro. who is convinced that warming up the engine is a complete waste of time.

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I argued that it's a good idea to make sure the oil is flowing in to the head properly to reduce eng. wear.
So do you warm up or not?

[DeKa]

I'm convinced it's a waste of time warming up and engine and does more damage than it's worth and wastes fuel.

An engine takes a LONG time to warm up at idle. Once on the road and under load however, an engine will warm up very very quickly.

As such, I would recommend you start the car and drive off straight away so it warms up as you drive. Don't over rev the engine until it has warmed up and you'll be saving yourself alot of wear as the critical period for engine wear where the engine is cold is a much much shorter period of time.

Derek 2_cents

[Rod Hagen]

Hi Luca,

With modern engines and modern oils (ie the ones that have been in use since the 1950's) it is recommended not to "warm up" the engine. It was of value back in the old days because tolerances were much larger and it took time for things to heat up and close up the gaps, get the oil films set up etc etc.

Driving off actually gets the temperature up to normal operating temperatures faster these days , minimising wear and reducing unnecessary emissions and fuel usage.

The recommended approach, almost universally, these days is to start the engine and drive off pretty much immediately. The only counter to this is that in automatic cars it is seen as a good idea to let it run for maybe a 30 secs or a minute to get the transmission fluids up to speed.

Its worth noting though, that although warming up is no longer recommended its not a good idea to overstress a cold motor. Drive fairly gently for the first few minutes.

Cheers

Rod

[Alan S]

Check this out. It's a site actually devoted to this subject by some crazy Yank. He could be right but for my money he's taking things to the extreme & beyond.....enjoy eek! eek! dance

<a href="http://www.mototuneusa.com/break_in_secrets.htm" target="_blank">http://www.mototuneusa.com/break_in_secrets.htm</a>

Alan S spanner

[pugrambo]

i walk out start the car walk back inside put my boots on and grab phone and anything else i need walk out and drive off
been in that habit all my driving life

[Luca]

I just finished reading this site and it's my understanding that warming up before driving it had is a must as it gives time for the piston and rings to seal up against the cylinder wall.
It repeatedly state "warm up the engine before running hard."
Anyway I've sent him an email to ask him more about piston slap and more on what he has written.

[nJm]

Some cars do seem to run better if left to idle for a little while. My 505 definately needs up to a minute before driving off so the damn auto choke can work everything out. That one minute is the difference between it stalling and running like crap for the first 50m, or driving normally.

Our Magna also likes to be given a few seconds otherwise the auto feels like it has fallen off the car when it changes from 1st to 2nd.

<small>[ 02 June 2003, 03:02 PM: Message edited by: nJm ]</small>

[Rod Hagen]

Alan S:
Check this out. It's a site actually devoted to this subject by some crazy Yank. He could be right but for my money he's taking things to the extreme & beyond.....enjoy eek! eek! dance

<a href="http://www.mototuneusa.com/break_in_secrets.htm" target="_blank">http://www.mototuneusa.com/break_in_secrets.htm</a>

Alan S spanner

Its not all THAT far off the process suggested back in the late 70''s by Repco for breaking in a rebuilt engine, Alan:

1) Don't let it idle.
2) Accelerate immediately to a speed comparable to a road speed of 25mph and maintain this speed until until temp reaches 180 degrees F.
3) When warmed up accelerate repeatedly at full throttle in top gear from 25 to 35mph.
4) avoid prolonged high speeds during first 2000 miles
5) avoid constant speeds. Vary speed between 30 and 50 mph and then use higher speeds towards the end of first 2000 miles.

Cheers

Rod

[Luca]

My eng. definately isn't new, or a stocker 4 that matter but I'm addiment that warming it for a minute or 2 is better for it that booting it from start up.
The oil needs to get to best operating temp to run to the head and then that annoying tapping noise of the cam goes away.
I'm gonna speak to a mate tonight who builds superbike motors and get his opinion.

[Rod Hagen]

Luca:
My eng. definately isn't new, or a stocker 4 that matter but I'm addiment that warming it for a minute or 2 is better for it that booting it from start up.
The oil needs to get to best operating temp to run to the head and then that annoying tapping noise of the cam goes away.
I'm gonna speak to a mate tonight who builds superbike motors and get his opinion.

It might run smoother, Luca, but that doesn't mean its better for the engine. Every decent source I've seen for years recommends AGAINST "warming up" the engine by letting it idle. You certainly shouldn't race the motor, but you should put it under light load as soon as possible after starting.

Cheers

Rod

<small>[ 02 June 2003, 04:50 PM: Message edited by: Rod Hagen ]</small>

[Pug307]

When I start up the car - I put the key in and turn it to the II position so the fuel lines are pressurised.

Once I start the engine, I let it idle for about 5 to 10 seconds, allowing the engine idle speed to settle down to normal and the engine light will extinguish upon doing so.

On a Volvo board I was told that this is a good idea as it allows the catalytic converter pre-heat process to complete properly. In any case, I don't see the point of putting the car into drive with 1500 rpm.

As the others say - just drive off, and don't push the car hard. I have this rule of not exceeding 3000 rpm when the engine is cold.

How much longer does it take for oil to reach operating temperature compared to coolant?

Cheers,

Justin

[DeKa]

Pug307:
When I start up the car - I put the key in and turn it to the II position so the fuel lines are pressurised.

Once I start the engine, I let it idle for about 5 to 10 seconds, allowing the engine idle speed to settle down to normal and the engine light will extinguish upon doing so.

On a Volvo board I was told that this is a good idea as it allows the catalytic converter pre-heat process to complete properly. In any case, I don't see the point of putting the car into drive with 1500 rpm.

Justin... allowing fuel pressure to come up sounds like something out a flight checklist wink Do you check the brakes before departure in your pre-drive run-ups? What about full control movement?

In an Auto I can see it would be a good idea to wait 5-10 seconds as the clunk as it drops into gear at 1500rpm can't be good for the transmission.

As an aside, I thought it took ~20 mins for a catalytic converter to warm up at road speed which is part of the reason cities suffer photochemical smog - all the short trips mean the catalytic converters never warm up properly so all the unburnt exhaust gases are just released to the atmosphere.

Derek

[Pug307]

Hahah,

Ahh, the good old pilot checklists, a good excuse for this behaviour Making sure you don't have any funny lights or indications, they're all good habits to have.

I've just done some reading, apparently catalytic converters get to operating temperature within 2 minutes of driving (350°C is optimal). <a href="http://www3.volvo.com/environment/pdf/envvolveng.pdf" target="_blank">Link.</a>. In addition, apparently 90% of a cars emissions comes from the first minute after startup (I'm assuming other than CO2) <a href="http://www.lynntech.com/licensing/chc/index.shtml" target="_blank">Link</a>.

Here is a graph from the good ol Swedes showing car emissions in the first kilometre after startup.

<img src="http://www.chem.brown.edu/chem12/catalyst/autofolder/fg8-7.jpg" alt=" - " />

As you can see, warming your engine up ASAP is the best thing you can do for it. Prolonged idling is about the slowest way you can do so. Most car manuals I've read advise against idling for prolonged periods of time as well (obviously the 5-10 sec idle isn't a for a prolonged period).

Cheers,

Justin

[Rod Hagen]

apparently catalytic converters get to operating temperature within 2 minutes of driving (350°C is optimal). Link.. In addition, apparently 90% of a cars emissions comes from the first minute after startup (I'm assuming other than CO2) Link.

Rather thought it might depend on how far you usually drive before stopping and letting the engine cool down again! Maybe if you say " apparently 90% of car emissions comes from the first minute after startup". Clearly though, this will depend heavily on a range of other factors, including the average trip length in the country concerned. Its one of those "grab bag" figures that looks impressive but might not mean much. Still, as you say, its clear on all of the evidence that cold starts are nasty, and the less of them you do the better.

You'll find that a few people other than the good old Swedes have had a bit of a look at this one too. See, for example, the US FWA page at <a href="http://www.fhwa.dot.gov/environment/aqfactbk/factbk13.htm" target="_blank">http://www.fhwa.dot.gov/environment/aqfactbk/factbk13.htm</a>

The CSIRO and other Australian agencies have also taken a bit of a squiz by the way.

The figures don't always agree.

But essentially you are right. Lots of cold short trips are bad news.

Cheers

Rod

<small>[ 02 June 2003, 06:46 PM: Message edited by: Rod Hagen ]</small>

[XTC]

Rod Hagen:
But essentially you are right. Lots of cold short trips are bad news. Cheers Rod

Not to mention the damage they can do to your battery ... Nothing drains a battery more then starting a car - and if you don't give it time to recharge cause of very short trips, eventually it will drain short of it's expected life.

XTC206

[dino]

totally agree...same reason why many taxis will get 7, 8, even 9 years out of a battery and an engine with 500 000 k without a major rebuilt....

cheers
dino

[Pugnut403]

I have no experience with modern engines, but I know that if I don't let the engine warm up in the Transit it won't run properly for quite a while.
My favoured method is to let the engine idle for at least 10 seconds to let the oil pressure squirt everything with oil properly, as the oil pressure light can go out before the tappets etc are nice and lubricated, and then run it at 1000-1500rpm for a few minutes to warm up. It always runs nicer, and I have found that a lot of old engines, particularly '70s Japanese engines, run like crap if you try to just drive away. 2_cents

[Luca]

Hey.. I got a reply from Pat (the american guy from the above site) and he said warm up the motor for 2 -5 minutes and then drive it hard straight away...
Aparently the oil warms up to optimum operating temp and when driven hard it "beds" the cam in. (using his teminology).

So what's the verdict... do we do it??

[Sergetov]

My cressida had a new engine put in about 3-4 months ago now. My mechanic said to me:
-Drive it HARD
-Do NOT let it idle for longer than the minimal amount possible
-Avoid stop-start traffic if possible
-Take it to the hills!
-Don't push her when she is cold

In the handbook the I noticed it mentions my car does'nt engage 4th gear until 3-4 minutes of driving which was interesting. (its auto of course)

As for changing gears in a cold auto below 1500rpm? whats with that? The Cressida idles at about 1000rpm, then again, maybe it is self destructive. Every morning when I put it in reverse, it carries out the function in a most undignified manner.

[Rod Hagen]

Luca:
Hey.. I got a reply from Pat (the american guy from the above site) and he said warm up the motor for 2 -5 minutes and then drive it hard straight away...
Aparently the oil warms up to optimum operating temp and when driven hard it "beds" the cam in. (using his teminology).

So what's the verdict... do we do it??

Why don't you go to the horse's mouth , Luca. Ask Peugeot.

As for "bedding in the cam", I've never heard so much nonsense in my life. I suggest you give our American mate a very wide miss.

You'll find an interesting (and amusing) takle on the question at <a href="http://cartalk.cars.com/Columns/Archive/1995/August/11.html" target="_blank">http://cartalk.cars.com/Columns/Archive/1995/August/11.html</a>

There is another one at <a href="http://www.motorway.com/Stories/0,1413,243%257E26448%257E1333087,00.html" target="_blank">http://www.motorway.com/Stories/0,1413,243%257E26448%257E1333087,00.html</a>

There is another one at <a href="http://autonet.ca/EdmontonDrive/Stories.cfm?StoryID=6999" target="_blank">http://autonet.ca/EdmontonDrive/Stories.cfm?StoryID=6999</a>

On balance it looks like a warm up might not be quite as bad as it used to be (unless you still have a car with a carby), though it remains , at best, a complete waste of time, fuel and money.

Cheers

Rod

<small>[ 03 June 2003, 08:48 PM: Message edited by: Rod Hagen ]</small>

[Pugnut403]

Talk about auto boxes reminds me. I have done a bit of driving in a friend's Humber Vogue automatic, and if it as driven away cold, the box will NOT go into 3rd gear for a couple of minutes, and for a further few minutes it won't go into 3rd below 40mph. After about 3-4 minutes in 2nd gear it goes into 3rd at 25-30mph like it should ( except when you have your foot planted in the kickkdown of course ).

[Warren Gordon]

If you live in town it shouln't need to be warmed up if you live out in the country where in the winter mornings it is below 0 or less and you go straight ot highway speed ( as I do ) them warming up first is a very good practice I believe.

[JohnW]

Luca:
Can i ask 4 some feedback please...
I've had a lengthy discussion with my bro. who is convinced that warming up the engine is a complete waste of time.

I argued that it's a good idea to make sure the oil is flowing in to the head properly to reduce eng. wear.
So do you warm up or not?

We have a steep driveway. I have taken the view for a long time that prolonged warmup at idle or fast idle (i.e. under about 1,000 rpm) is not a good idea. Much better to get the revs up once oil pressure is established in my view and get the warmup period as short as possible.

There was an old dictum that said, more or less "revs never hurt an engine but lugging does". So go light on the accelerator until it is at operating temperature, by which time oil has splashed everywhere thoroughly and proper clearances have established.

We give our 306 20-30 seconds to settle down and of course, the Xantia gets what it needs to have hydraulic pressure. That's not long either.

I knew a guy with a Mazda van about 15 years back (a truly horrible thing) whom meticulously warmed it up every morning. Engine lasted about 80,000 km if I remember rightly then started really using oil. Poor ring lubrication at low temperatures, fuel dilution etc, was my diagnosis then.

JohnW