Engine Warmup

[JohnnyJohnJohn]

Hey guys,

Just want to find out what are the main factors that could contribute to long engine warmups?

I have a civic with a D16A8 in it and 200km on the clock, after not being used overnight it takes quite a long time to warmup to optimum working temp? avg 5-10mins somtimes even more? is this normal? my previous cars didnt take that long 5mins tops, but then again this is my first honda so im still working the kicks :confused:

Thanks.

[SHU-ES1]

could be thermostat? i had this issue with my 03 civic where it wouldn't warm up to optimal temperature at all because of thermostat fault. hows the fuel consumption like?

[mnc]

5-10 minutes in winter sounds about right. after 5-10 minutes it should be 1/4 on the gauge

[dness]

^ agreed.

5-10 minutes for me also on a cold winter night.

[JohnnyJohnJohn]

ah fair enough, i get more or less an avg of ~300km per tank (45litres?) on 95octane fuel, but yea ill still have to replace a few more parts so hopefully itll get better?

[CRXDEL501]

sounds like the thermostat buddy. there is a thread on how to test your thermostat, ill try and find it for you

[CRXDEL501]

ive tried to have a look for you, but cant seem to find it. but it definitely sounds like the thermostat.

take out your thermostat and stick it in boiling water. if it doesnt open up i think its buggered. can someone please confirm this? it was ages ago i did this on my car. my memory is a bit blurry.

[mocchi]

D18A8? 1.8 litre?
what civic has that?

[SlobberGoat]

I think he meant to type D16A8.

[Bludger]

sound s normal

[OMG.JAI xD]

ive tried to have a look for you, but cant seem to find it. but it definitely sounds like the thermostat.

take out your thermostat and stick it in boiling water. if it doesnt open up i think its buggered. can someone please confirm this? it was ages ago i did this on my car. my memory is a bit blurry.

Its abit different with a thermostat stuck open.
You can do this on the car. Top hose should ALWAYS be hotter than the bottom hose (or the other way around.. really depends on the setup of the cooling system. But generally one hose should be cooler than the other. ON WARM UP ONLY).

If you just start your car and let it warm up. Spend a few minutes just in the engine bay. Feel the top hose as it gets warm. And feel the bottom hose. If the bottom hose gets warm before the top hose is really hot. Your thermostats stuck open slightly.

Usually a cooling system works in this order. Warms up Thermo closed, fans off. NOT (normal operating temperature) Thermostat opens and circulates coolant.
AOT (above operating temperature) the thermoswitch/fan switch/ temp switch will reach a threshold thatll send information to the ECU to activate the fan relay. Or the signal goes straight to the relay from the switch itself. Different setups but they all work the same way.

In simple terms. Thermos closed at warm up. Thermos open to maintain engine cooling temp. The fans will turn on if the circulating coolant cannot be cooled anymore without the help of radiating the heat.


An even easier way to check your thermos failed open is to drive on the highway. If the temp gauge falls its stuck open.

[DLO01]

Hey guys,

Just want to find out what are the main factors that could contribute to long engine warmups?

I have a civic with a D18A8 in it and 200km on the clock, after not being used overnight it takes quite a long time to warmup to optimum working temp? avg 5-10mins somtimes even more? is this normal? my previous cars didnt take that long 5mins tops, but then again this is my first honda so im still working the kicks :confused:

Thanks.

5-10mins? Is this at at Stand still and at idle? If so it will take 10 mins to get to normal operating temp. If its Start then drive, it should only take a few mins to warm up.

[mnc]

5-10 at idle lols.

Soo is my thermo stuck open then? I drive a dc2r and when i drive on the freeway and the radiator is getting gushed with freezing cold air my thermo drops though? =S

[OMG.JAI xD]

5-10 at idle lols.

Soo is my thermo stuck open then? I drive a dc2r and when i drive on the freeway and the radiator is getting gushed with freezing cold air my thermo drops though? =S

Really depends on how long it took you to get on the freeway. Regardless you warm up the car for the 10 mins. If the highway is 1 min away it will drop momentarilly.
However. In saying that, your temperature should NEVER drop if youve driven for quiet some time.
I have driven on one of those icy mornings sydney had, 30 min drive to work with constant 70km/h zones and the car did not warm up. It stayed cold the whole trip.
Thats an exception though when temperatures are at 2-0 degrees.

Only thing i can think of with your case is that you have an aftermarket thermostat. Or aftermarket fan switch or worse... both.
If thats the case. Those aftermarket components are to be used for racing. Not road use. Well you can. But wearing your engine components faster is not worth the 50 bux.

Running your engines cooler is NOT good for your engine. It does NOT prolong your engine life.
It is good however for racing because the engine is always working hard. Street driving the engine is pretty much walking in the park.
A colder engine has bigger clearances in the engine (ie. rings, bearings etc) those clearances were engineered to close up as engine warms up.

If you do not have any aftermarket cooling components (thermo or fan switch). Then id recommend to check and replace if required, your thermostat.
If you do have aftermarket components. I highly recommend to replace them with OEM ones. UNLESS you do ALOT of hard driving/track work.

[JohnnyJohnJohn]

D18A8? 1.8 litre?
what civic has that?

crap yea sry didnt realise its a D16A8


5-10mins? Is this at at Stand still and at idle? If so it will take 10 mins to get to normal operating temp. If its Start then drive, it should only take a few mins to warm up.

yup at a stand still during idle.


Its abit different with a thermostat stuck open.
You can do this on the car. Top hose should ALWAYS be hotter than the bottom hose (or the other way around.. really depends on the setup of the cooling system. But generally one hose should be cooler than the other. ON WARM UP ONLY).

If you just start your car and let it warm up. Spend a few minutes just in the engine bay. Feel the top hose as it gets warm. And feel the bottom hose. If the bottom hose gets warm before the top hose is really hot. Your thermostats stuck open slightly.

Usually a cooling system works in this order. Warms up Thermo closed, fans off. NOT (normal operating temperature) Thermostat opens and circulates coolant.
AOT (above operating temperature) the thermoswitch/fan switch/ temp switch will reach a threshold thatll send information to the ECU to activate the fan relay. Or the signal goes straight to the relay from the switch itself. Different setups but they all work the same way.

In simple terms. Thermos closed at warm up. Thermos open to maintain engine cooling temp. The fans will turn on if the circulating coolant cannot be cooled anymore without the help of radiating the heat.


An even easier way to check your thermos failed open is to drive on the highway. If the temp gauge falls its stuck open.

oh man thats definately helpful advice ill def check this out when i get the chance and see how it goes :thumbsup:

in saying that if it is normal with warming up of the engine would a start then drive scenario be bad for a car with no warm up? if so what would be the threshold for an adequate warmup? i tend to say its ready once it hits anything under ~1000rpm but thats just me since.

[DLO01]

Start car, make sure you have oil pressure (light goes out), then go. Drive normally till water and oil are warm. Note that oil takes longer to warm up than water.

[EK1.6LCIV]

if you had an oil pressure guage and its above the 17psi mark, its still warming up :)

should be over 75 when you first turn the car over

I normally make a coffee after I turn the key in winter, walk back out after 2 mins and leave the estate driving below 4k, by the time Im on the motorway in under 5mins its closer to being 50psi (I find normal for highway speed when it's properly warmed)

Hondas really need an oil pressure gauge (I run a short sweep autometer gauge that reads from 0-100psi), best insurance :)

[OMG.JAI xD]

oh man thats definately helpful advice ill def check this out when i get the chance and see how it goes :thumbsup:

in saying that if it is normal with warming up of the engine would a start then drive scenario be bad for a car with no warm up? if so what would be the threshold for an adequate warmup? i tend to say its ready once it hits anything under ~1000rpm but thats just me since.



Well with cars fitted with a FITV and a IACV (which is for cold and warm idle) I tend to warm the car up until you see the revs go down to close to what it usually idles at.

For instance. A B series will idle at around 1.5Krpm mark when dead cold. Revs should go down once it starts to warm and crosses over to the IACV. Thats usually when i start driving.
For thrashing however is a different story.
Usually i wait for the needle to reach the normal operating position while driving. And drive a bit heavy of the throttle for at least another 5-10 mins before I do any kinds of thrashing.
Im drving a turbo though, so i take extra precautions.
N/A really should cope with a thrashing as long as its normal operating temp.

This is all when gauges come into play. With aftermarket gauges that are close to accurate, youll sorta know the right times to thrash a car.
Oil temp takes forever to heat up.