Warm up behaviour.

[8YARWY]

After the recent cold weather and owners being irritated by the RS3 not defrosting quickly I monitored what the cooling system was actually doing today.

Time was just after 5 pm and the car was saying -1 C

Start up and idling for a couple of minutes.
Cold air from the vents.
Temp of water is pretty quick to reach 60 C

A further minute
Temp hits 71C

Some mildly warm air comes through the vents

Temp now drops again as the ECU is managing the Coolant
Air from vents goes back to cold

Longer to recover this time and as it passes 70C I have warm air from the vents again.

Temp dropping again

Warm air from the vents stops and it’s cold again.

Oil temp is starting to show at 47C

After 10 mins driving
Water now at 83 vs Oil at 82C
I now have warmer air.

Lastly

Car was parked up for 15 mins then restarted
Water still up in the 80’s
Oil has dropped into 70’s

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[Mike.46]

Interesting stuff, Thanks for taking the time and trouble

So basically not just a one shot device either, it's stopping water flow until the block stays above 60c with the pump operating,

If the temp reduces below 60c it looks like it operates again to stop the circulating water

Just plugging, or by passing the vacuum would give a normal, but slower warm up I guess but with some heat ...................................(just need to know whether the water pumps requires vacuum or no vacuum to work as a pump )

 

[itsbigyellow]

Awesome work @8YARWY , certainly reflects my general experience

 

[Mike.46]

I'd also wager that 'IF' I did fool the pump to circulate all the time the ecu would throw a fault to say the warm up process is not operating correctly (probably limp home with a 100 mile timer to get the car to an Audi dealership asap as it is breaking emssions regulations )

 

[Snake Pliskin]

After the recent cold weather and owners being irritated by the RS3 not defrosting quickly I monitored what the cooling system was actually doing today.

Time was just after 5 pm and the car was saying -1 C

Start up and idling for a couple of minutes.
Cold air from the vents.
Temp of water is pretty quick to reach 60 C

A further minute
Temp hits 71C

Some mildly warm air comes through the vents

Temp now drops again as the ECU is managing the Coolant
Air from vents goes back to cold

Longer to recover this time and as it passes 70C I have warm air from the vents again.

Temp dropping again

Warm air from the vents stops and it’s cold again.

Oil temp is starting to show at 47C

After 10 mins driving
Water now at 83 vs Oil at 82C
I now have warmer air.

Lastly

Car was parked up for 15 mins then restarted
Water still up in the 80’s
Oil has dropped into 70’s

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As the others have said - fantastic thank you.
I thought I was going mad thinking it warmed up then went cold again so your research validates that.
Very very interesting mate

 

[HulkRS3]

I've left mine idling in the drive for over 25 minutes and the inside is still misted up quite heavily. I can't bring myself to wipe the window!

 

[Mike.46]

I wonder if the 60c water pump start stop is accessible via VCDS ?

 

[8YARWY]

I wonder if the 60c water pump start stop is accessible via VCDS ?

Doubt it, especially if this is emissions related behaviour from the ECU.....you'd need to look in 01 Adaptions to see if there's anything temp related.

-7 c here this morning and leaving the house to go to the unit i can literally feel the heat supply kangaroo between warm then cold, it would seem the ECU will only give you the full heat once it's happy with Oil & Water being similar temps, as in the picture i posted yesterday.

 

[Prodigy]

After the recent cold weather and owners being irritated by the RS3 not defrosting quickly I monitored what the cooling system was actually doing today.

Time was just after 5 pm and the car was saying -1 C

Start up and idling for a couple of minutes.
Cold air from the vents.
Temp of water is pretty quick to reach 60 C

A further minute
Temp hits 71C

Some mildly warm air comes through the vents

Temp now drops again as the ECU is managing the Coolant
Air from vents goes back to cold

Longer to recover this time and as it passes 70C I have warm air from the vents again.

Temp dropping again

Warm air from the vents stops and it’s cold again.

Oil temp is starting to show at 47C

After 10 mins driving
Water now at 83 vs Oil at 82C
I now have warmer air.

Lastly

Car was parked up for 15 mins then restarted
Water still up in the 80’s
Oil has dropped into 70’s

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Thanks for the hard work!
I now know it isn't "just me"....imagining things.......

 

[Mike.46]

Just watched a few readings on VCDS, I selected coolant temperature and a vent temperature with the unit set to max defrost (thinking that might overide the water pump control)...............but it doesnt (there is also Coolant pump control in advanced settings, but I only found that later)

As far as I can see the coolant temperature comes up pretty quickly and the heater vent starts to rise from 1c but only when the coolant temperature reaches 70c, not the 60c in the self learning guide, theres obviously some lag measuring but the water circulation appears to stop again at about 68c (need to watch the coolant pump in advanced settings next time)

Coolant temp will continue to fall toaround 60c before climbing to 70c and re energising the coolant pump.

This repeats 3 to 4 times (staionary) before the coolant temp finally stays above 70c........................stupid idea IMHO

 

[8YARWY]

Just watched a few readings on VCDS, I selected coolant temperature and a vent temperature with the unit set to max defrost (thinking that might overide the water pump control)...............but it doesnt (there is also Coolant pump control in advanced settings, but I only found that later)

As far as I can see the coolant temperature comes up pretty quickly and the heater vent starts to rise from 1c but only when the coolant temperature reaches 70c, not the 60c in the self learning guide, theres obviously some lag measuring but the water circulation appears to stop again at about 68c (need to watch the coolant pump in advanced settings next time)

Coolant temp will continue to fall toaround 60c before climbing to 70c and re energising the coolant pump.

This repeats 3 to 4 times (staionary) before the coolant temp finally stays above 70c........................stupid idea IMHO

Yes exactly, the initial Temp from cold goes up rapidly until 60+ C

I’m guessing thermal management on this OPF 2.5 is a lot stricter to keep things in check.


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[Mike.46]

So Audi trying to get Motor and cats/OPF to operating temperature to get within emission rules.

I guess they havent figured into the equation that people will leave their cars warming up for an extra 10 minutes these cold mornings

 

[RSt3ve]

Typical short sightedness.

Not that it's minus 5 every day everywhere, but surely they could've built in a link to outside temp to bias interior warm up first in colder weather.

A timely reminder we're buying premium brands, not premium cars...

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[Mike.46]

I thought maybe the 'full demist' button might give the heater some warmth, but no.

 

[RSt3ve]

Makes me wonder, is the a UK thing or likely to be EU too?

I really can't see this being favourable in parts of Europe where they have real winter weather and I'd be surprised if a few people haven't gone back to Audi for investigation.

The wife's micra is blowing warm in about 1.5mins at the moment and the block in that thing would fit in a handbag.

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[8YARWY]

Makes me wonder, is the a UK thing or likely to be EU too?

I really can't see this being favourable in parts of Europe where they have real winter weather and I'd be surprised if a few people haven't gone back to Audi for investigation.

The wife's micra is blowing warm in about 1.5mins at the moment and the block in that thing would fit in a handbag.

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It’ll be the same.

Maybe different on the USA cars as they don’t have OPF’s

My 8V wasn’t like this at all.


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[rngDeadeye]

What happens if you sit there at 3000rpm for 5 mins like we used to do in the old days?

 

[Snake Pliskin]

Worse than ever !!!!!

 

[Southall87]

What happens if you sit there at 3000rpm for 5 mins like we used to do in the old days?

Might try this in the morning... hope the neighbours don't mind!

 

[Mike.46]

What happens if you sit there at 3000rpm for 5 mins like we used to do in the old days?

I was doing a bit of that this morning, a rough time scale
I started car, reversed out of garage, stopped car
Plugged in vcds and restarted car, by the time I selected HVAC and coolant temperature + vent temperature the coolant was 45c............ probably 3 minutes running
It then took the best part of another 3 minutes for the coolant to get to 70c, nothing happened at 60c coolant temp
At 70c the vent temperature increased quickly to about 17c and then started to go down, the coolant temp had now reduced to about 50c
Coolant rose again to 70c over about a minute, the vent temperature shot up to 25c and then reduced again, coolant temp now at about 57c

Each cycle became shorter and hotter until the 70c coolant was maintained with the vent temperature still hot

 

[Daggerit]

I wonder if it’s just the thermostat opening and closing to keep the water temp between a range of something like 55-70°C. Each time it opens and circulated the temp will drop when it circulates some cold water and then it shuts again to keep warming it and cycles like that until it’s fully up to temp?


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[8YARWY]

I wonder if it’s just the thermostat opening and closing to keep the water temp between a range of something like 55-70°C. Each time it opens and circulated the temp will drop when it circulates some cold water and then it shuts again to keep warming it and cycles like that until it’s fully up to temp?


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More sophisticated than that.
The ECU is in control of what goes on

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[Daggerit]

More sophisticated than that.
The ECU is in control of what goes on

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I was assuming the ECU would open and close the thermostat rather than it being purely mechanical, so still wondering if it’s doing it within the parameters?


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[8YARWY]

I was assuming the ECU would open and close the thermostat rather than it being purely mechanical, so still wondering if it’s doing it within the parameters?


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What Parameters ?




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[Daggerit]

What Parameters ?




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Trying to keep the temp in some sort of range, something like 55-70° by the sounds of things? Opening and shutting the thermostat as it hits the upper and lower temps is what I was wondering.


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[Mike.46]

Trying to keep the temp in some sort of range, something like 55-70° by the sounds of things? Opening and shutting the thermostat as it hits the upper and lower temps is what I was wondering.


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No, Look at the post from 8YARWY in 'not bonding with my car' thread to see the detail on the water pump, the initial 'fast' engine warm up control is performed by the ecu stopping the main coolant pump from circulating water, hence no water to heater, also no flow through the water bottle or indeed the turbo charger, once the sensor sees 70c it activates the circulating water pump and you get a burst of 70c water into the heater and obviously a burst of cold water back into the engine which reduces engine temp down below 70c and the ecu de-activates the main water pump again.

Lots of smaller engined VW's use the same system, 1.4tsi etc

And PS: they give trouble as well, refusing to open and boiling the engine.....................looking forward to that one not

 

[Daggerit]

No, Look at the post from 8YARWY in 'not bonding with my car' thread to see the detail on the water pump, the initial 'fast' engine warm up control is performed by the ecu stopping the main coolant pump from circulating water, hence no water to heater, also no flow through the water bottle or indeed the turbo charger, once the sensor sees 70c it activates the circulating water pump and you get a burst of 70c water into the heater and obviously a burst of cold water back into the engine which reduces engine temp down below 70c and the ecu de-activates the main water pump again.

Lots of smaller engined VW's use the same system, 1.4tsi etc

And PS: they give trouble as well, refusing to open and boiling the engine.....................looking forward to that one not

Ok then, same theory though. It circulates then stops when it’s cooler, then circulates again when the water in the block is warm and continues until it’s warm enough to run the pump continuously.

Was just throwing an idea out there as to why the temperature of the coolant seems to cycle rather than just come up to temp and stay there.


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[8YARWY]

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[Daggerit]

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Good info. The text in the pump detail seems to explain what my theory is, in that it doesn’t pump water below 60° (I know I said 70°, but that was just a guess). So it must start pumping, have the whole system cool down below 60° again, stop pumping, warm up, start pumping, cool off, stop pumping, etc., etc. ‘innovative cooling’.


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[RSt3ve]

I've had much better results today, -7 first thing but I stayed out the car for 2 mins after starting and was able to drive straight off (after clearing outside during my 2 mins of chill time).

The condensation caused by sitting in the car is a massive, especially if sitting there chuntering about how ****** crap the demisting is.

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[jaypers777]

My car is garaged. Took it out yesterday and outside temp was showing as -6. As you would expect, idle speed seemed a little high for a while. Obviously nothing to clear so headed off straight away. Not got any technical figures to back this up but car seemed to warm up very quickly and I had nice warm air coming through the vents within a couple of miles.

 

[Snake Pliskin]

Agreed - it warms up much quicker when driving than stationary.

 

[Mike.46]

Good info. The text in the pump detail seems to explain what my theory is, in that it doesn’t pump water below 60° (I know I said 70°, but that was just a guess). So it must start pumping, have the whole system cool down below 60° again, stop pumping, warm up, start pumping, cool off, stop pumping, etc., etc. ‘innovative cooling’.


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It does say 60c on the self learning guide but watching the coolant temp on vcds it is 70c before the vent temperature from vcds shows the 'pump' is circulating water through the heater

Common sense says if you could see through the windscreen and could drive off immediately the on-off effect of the pump cutting in and out should in theory be less.
Also on the common sense theory with Audi/VW managing engine warm up in preference to owner comfort and safety (being able to see where your going) I would have thought either a heated screen or the ceramic heater (sits in with the heater) from many of their diesel options would make sense.

Golf R apparently does not have the same system although a lot of the smaller engined Golfs do

 

[8YARWY]

Agreed - it warms up much quicker when driving than stationary.

Always will Mate, they used to say it was better to drive off rather than let the car Idle for too long when cold

When i flashed the 8V i turned down the high idle of 1400/1100 when cold, spoke to the guy who wrote me the file for stage2 and he suggested putting back on, he said Audi have that high cold start Idle for a reason ( move the Oil to parts that require it ) the higher Idle generates more pressure for pumping the cold oil up top.

 

[RS3ree]

I’ve used rain x anti fog on the inside glass and now I can just get rid of the ice on the outside and drive straight off. I was starting to wonder if there was a fault it was so slow to demist. The heaters then get going so much quicker once the engine is working. Defo the slowest warming up car I’ve owned

 

[flybynite]

Makes me wonder, is the a UK thing or likely to be EU too?

On the MQB there was the addition of an electric heating element into the heater box on some cars. You would have though it sensible to fit it on cars for cold climates and cars that were slow to heat like diesels but it seemed to be random. Quite a common retrofit but needed a heavy fuse (100a IIRC). My TSI wagon had it fitted and you got heat withing seconds. Others without it took ages to heat. Cost saving on the 8Y?

Always will Mate, they used to say it was better to drive off rather than let the car Idle for too long when cold

Completely agree but I always understood it to be for the gearbox, at idle (clutch engaged of course) you were spinning the idler shafts with out the splash lubrication from the rest of the gearbox. Still makes sense for the engine as it is always easier on the engine to be reved gently, same as running in.

When i flashed the 8V i turned down the high idle of 1400/1100 when cold, spoke to the guy who wrote me the file for stage2 and he suggested putting back on, he said Audi have that high cold start Idle for a reason ( move the Oil to parts that require it ) the higher Idle generates more pressure for pumping the cold oil up top.

I'm curious, who was it that said that? was it Darin? I have to admit I would curious to see that written down. I have not read anything to indicate it is not just for the cats. When you get rid of the cold start, the car still has slightly higher idle when cold. It sounds like cars did before the emissions crap.

I have not worked on an engine that you could not get oil pressure up to the top within a few seconds using the starter motor. Idle should be enough pressure for anything unless you have a worn oil pump, but I can see how it would warm the cats quicker.

Modern oils protect so well, I can't see 500 rpm will make a difference to the oil unless you have ******** it by leaving it in the engine too long, in which case 500 rpm won't save the engine.

 

[8YARWY]

On the MQB there was the addition of an electric heating element into the heater box on some cars. You would have though it sensible to fit it on cars for cold climates and cars that were slow to heat like diesels but it seemed to be random. Quite a common retrofit but needed a heavy fuse (100a IIRC). My TSI wagon had it fitted and you got heat withing seconds. Others without it took ages to heat. Cost saving on the 8Y?View attachment 265215


Completely agree but I always understood it to be for the gearbox, at idle (clutch engaged of course) you were spinning the idler shafts with out the splash lubrication from the rest of the gearbox. Still makes sense for the engine as it is always easier on the engine to be reved gently, same as running in.

I'm curious, who was it that said that? was it Darin? I have to admit I would curious to see that written down. I have not read anything to indicate it is not just for the cats. When you get rid of the cold start, the car still has slightly higher idle when cold. It sounds like cars did before the emissions crap.

I have not worked on an engine that you could not get oil pressure up to the top within a few seconds using the starter motor. Idle should be enough pressure for anything unless you have a worn oil pump, but I can see how it would warm the cats quicker.

Modern oils protect so well, I can't see 500 rpm will make a difference to the oil unless you have ******** it by leaving it in the engine too long, in which case 500 rpm won't save the engine.

No I’d turned the cat heating off, however the ECU still idles the car at 1100rpm so I turned that down also to 750rpm.

Darin suggested I turned it back up so I did.

It’s a fickle old game tuning non of us are experts so have to listen / learn from people with more experience.

I had initially started with Jared (VLM) and his file was great, however there were things that I wasn’t 100% with, idling on the higher lift exhaust lobes was one, the car sounded immense at idle running on those, however after discussing it with 2 other ‘experts’ I reverted the change.


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