197: Warming up the engine?

[Rishi]

Isit a good idea to let the engine warm up for a few minutes idling before setting off?

When i start from cold i have to be gentle & change gears fast until the engines a bit warm, the car just feels like it doesn't want to be driven yet, so im thinking it would be a good idea to let the engine warm up idling for a couple minutes then get going rather than trying to push it at all while its cold, but i think i read on here somewhere that this is a bad idea?

 

[adam1942]

technically you're suppose to drive it as soon as you start it so the carbon canister does not fill with a substance is what i'm told.. just keep the RPM low slowly building it up for 10-15 minutes

 

[pez1356]

I might be wrong but I'm fairly sure there's a different map or something to that effect on it until it's fully warmed up. To protect the engine I assume, hence why at first it feels like it just won't rev atall! Unless it's a very cold morning mine's normally warmed up after 5mins or so of gentle driving.

 

[Rishi]

Yeah it doesn't take long to warm up at all, it's just the other day i started her up then forgot i had to call someone so i left the engine running for about a minute, then when i got going i could feel straight away the engine was warmed up & ready to go...usually when i pull off straight away its feel so dull, so i thought maybe its better to leave it running even if for only 1 minute as it seems to make a big difference...

 

[roystinho]

I normally give it 2 songs before I let rip. Should be warm enough by then

 

[Paul]

Its not a problem to leave it a minute. I you shouldn't leave it idling any longer than that though.

The engine does run differently until up to temp, I am sure Si will provide the techinal info but its to get the cat hot and working for emission regulations.

You just have to drive with light feet during this phase and heavy feet the rest of the time! Nobody can say the car doesn't have character LOL

 

[BenW]

Best to drive it as soon as you start it, warms up quicker this way, minimising the wear and tear caused by cold oil.

It does have a different cold map, it will run a richer mixture. This will reduce carbon dioxide emissions (Whilst increasing all other emissions!!) but will also help to get the engine up to temperature more quickly.

 

[Graeme GTR]

and youll be ona lower limiter, think i hit the limiter at 5k something on cold, was in a bad mood at the time, it didnt help....

 

[Arran]

I been experimenting since using v-power has slightly bought back the cold start issue I don't seem to get on momentum. I've found flooring the accelerator up to 3k only and changing gear up to fourth helps. So by about 30 mph I am in fourth. Then after about 3 mins it's gone.

 

[PB.200]

Don't assume the engine is warm just cos the water temp is "normal"

The oil can take a bit longer to catch up. I use the RS Monitor to check temp before giving it the berries.

 

[GlassJaw]

Good point PB

The temp gauge on the rev counter denotes the water.

When that's spot on I'll give it a mile or two then open the taps

 

[BenW]

Expect the coolant to be warmed up after ~5 mins
Expect the oil to be warmed up after ~15 mins

 

[gazb197]

In the year of owning a 197 I started it and left it running almost every time I drove it

 

[Foxspeed]

Good point PB

The temp gauge on the rev counter denotes the water.

When that's spot on I'll give it a mile or two then open the taps

Expect the coolant to be warmed up after ~5 mins
Expect the oil to be warmed up after ~15 mins

the engine also has a oil cooler/heat exchanger - to provide rapid warm up of oil

as for emissions - co2 emissions are directly proportional to fuel consumption - a cold engine runs richer and therefore uses more fuel and hence produces more co2

 

[SarGara]

In the year of owning a 197 I started it and left it running almost every time I drove it

This. I leave my 200 running for 5~10 mins every morning prior to driving it to work. Theres a nasty short sliproad onto a NSL dual carriageway where you go from 30 > 70 so i cant afford for the car to be kangarooing.

 

[BenW]

as for emissions - co2 emissions are directly proportional to fuel consumption - a cold engine runs richer and therefore uses more fuel and hence produces more co2

Wrong way around, you get more CO2 emissions when running a lean mixture. You do however get more CO emissions when running richer. This is because in a rich mixture there is a reduced ratio of fuelxygen (O2) and therefore it is not as easy to form CO2. However as CO only needs half an O2 molecule this becomes easier to form.

I've explained that in very basic terms but you get the jist. That comes from experimental data I recorded a few weeks ago

 

[Foxspeed]

Wrong way around, you get more CO2 emissions when running a lean mixture. You do however get more CO emissions when running richer. This is because in a rich mixture there is a reduced ratio of fuelxygen (O2) and therefore it is not as easy to form CO2. However as CO only needs half an O2 molecule this becomes easier to form.

I've explained that in very basic terms but you get the jist. That comes from experimental data I recorded a few weeks ago

true but i am only going on the fuel trials i did a few years back with the following data -

1ltr petrol contains - 2.28kg co2 (approx)
1ltr diesel contains - 2.63kg co2 (approx)

the whole point of the eec fuel test cycle but given the changes due to engine temperature and air fuel mxiture then yeh QED as they say!

 

[ado]

Expect the coolant to be warmed up after ~5 mins
Expect the oil to be warmed up after ~15 mins

I've found that when the coolant temp need reaches in normal position the oil is at around 80C.

 

[BenW]

1ltr petrol contains - 2.28kg co2 (approx)
1ltr diesel contains - 2.63kg co2 (approx)

the whole point of the eec fuel test cycle but given the changes due to engine temperature and air fuel mxiture then yeh QED as they say!

Fuel doesn't contain any CO2 though, presumably those figures are calculated on theoretical emissions at stoichiometric conditions. Just because you have more fuel doesn't mean you have more CO2 for reasons I pointed out above

Here's my data to clarify things, equivalence ratio of 1 = stoichiometric AFR (i.e 14.77:1), equivalence ratio of 0.7 is AFR of 20:1 and equivalence ratio of 1.1 is AFR of 13:1



I have some more plots for NOx and HC, as well as all these at different throttle positions if it's of any interest :thumbup:

 

[Foxspeed]

Fuel doesn't contain any CO2 though, presumably those figures are calculated on theoretical emissions at stoichiometric conditions. Just because you have more fuel doesn't mean you have more CO2 for reasons I pointed out above

Here's my data to clarify things, equivalence ratio of 1 = stoichiometric AFR (i.e 14.77:1), equivalence ratio of 0.7 is AFR of 20:1 and equivalence ratio of 1.1 is AFR of 13:1



I have some more plots for NOx and HC, as well as all these at different throttle positions if it's of any interest :thumbup:

yeh sorry my bad did it in a rush!!!

but a standard amount of co2 is produced/released when a fossil fuel petrol-diesel-gas is burnt