winter heating and starting (TDI)

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speedfreak

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Hello,

Call me paranoid (hey, its all the problems reported here!!), but I just wanted to check my A2 is not malfunctioning as the manual is unclear on a couple of items.

1. I have a 1.4TDI, and there seems to be no requirements to pre-heat the engine - I just turn the key and the engine starts even if its 0'C. Should I be waiting for the yellow 'heater' sign to go out or is it Ok just to start it up right away?

2. My car has no air-conditioning, and so has the standard heating system with the three buttons below. The air-recirculation button and the rear screen heater are obvious enough, but what is the third button (the one with the green light)? Mine seems to make no difference - there is some vague reference to an economy mode and I seem to remember reading something about an additional winter heater. Is this button just there to turn the green light on and off, or does it actually perform a useful function?

Thanks for your help.
 
Hi,

Pre-heat is activated as soon as the doors are unlocked (will switch off soon after if car not started) and as a resault..

Under warm conditions (around +5) there is no problem with starting the car.

below this temp I would suggest that you wait for the heater symbol to go out, as the system my not be at the correct settings. (incorrect mixture settings or rough idoling)



Lee,
TDI SE,
Dolphin Grey,
6 Disc Changer (Fitted by me)
 
quote:Originally posted by shezlee

Hi,
Pre-heat is activated as soon as the doors are unlocked (will switch off soon after if car not started) and as a resault..
Click to expand...

Hi, do you mean that the engine starts glowing when you unlock the doors ?? Or that the additional heater starts when te doors are unlocked ??

This week my TDI was -12 celsius and when it finished glowing I've started. Funny how diesel engines have a way of letting you know that they're not happy at all. It started allright but the noise was raw and I had to switch gears around 12/1300 rpm.


Dennis de Held

Amulet Red 1.4 Tdi
 
The heater symbol relates to the ignition pre-heat, TDI only as these use glow plugs unlike the Petrol which uses spark plugs. This feature is realy only of use if you live in warm weather areas, as you don't have to wait for the glow plugs to heat up, you unlock - get in - start car...

If you live in colder areas this pre-heat of the glow plugs reduces the time you have to wait before starting the car but will not get rid of it.

As before I'd wait for the symbol to go out.

I have a similar noise and have to be carefull for a few miles.

Also if I stop within approx.. 1/2 mile from home (to get newspaper) there sounds if there is something running under the bonnet?? Any thoughts??

Lee,
TDI SE,
Dolphin Grey,
6 Disc Changer (Fitted by me)
 
I am not familiar with the A2 diesel, ours being a petrol, but as Lee says heating is temperature dependent and the direct injection engines needs less than the older indirect injection engines. I presume the A2 is DI and not IDI.

The glow plugs are there to heat the air, not the diesel, if the air is too cold the normal engine compression alone is not enough for combustion of fuel when injected. If the air needs warming and the plugs are not working the engine will not start - the diesel will not burn. The last diesel I drove regularly was a Vectra 2.0DI (nice engine, awful car) and I only saw the glow plug light on 2-3 times when air temperature was 2-3C below and the engine had not run for 24 hours. All other situations it started without pre-heat.

Ian

2002 1.4 Petrol SE, silver with climate control.
Why are all the A2s in Lichfield are silver ? ? ?
 
The 1.4 and 1.2 3 cylinder TDI engines are all PD (German is :pumpe Duese) - each cylinder has it's own fuel pump which means very high injection pressures can be achieved (even better than the common rail (high pressure tube that feeds all cylinders with fuel as seen on Peugeot HDI engines. PD engines are noisier than most modern diesels until warm. The 4 stroke petrol engine cycle (suck, squeeze, bang, blow) doesn't apply - Diesel combustion is a direct result of compressing the mixture of fuel and air until it goes bang - so no need for spark plugs. This makes them around 30 to 40 percent more efficient thermodynamically but the engines have to be built more stongly as compression ratios are much higher than comparable petrol engines. So a 1.4 TDI engine is much heavier than a 1.4 petrol. The 1.2 TDI is all aluminium whereas the 1.4 is ally head, iron block.

Diesels tend to be clattery by the nature of their combustion process c.f a petrol engine. But they tend to last longer because the fuel itself is a lubricant (petrol is a cutting fluid) and offer maximum torque at lower revs (less revs means longer life.

Glo plugs are just for cold starting as above



Lukas

First A2 1.2 TDI in UK
Style pack + Chorus + Advance pack + winter wheels + iRiver MP3CD
 
quote:Originally posted by shezlee
Also if I stop within approx.. 1/2 mile from home (to get newspaper) there sounds if there is something running under the bonnet?? Any thoughts??
Click to expand...

Should be the webasto additional heater kicking in. You should be able to feel the hot air coming fom the exhaust. The exhaust is located under the front bumper at the right side of the car (european car), just below the light.
That's the famous additional heater that kicks in, burns diesel and helps the eninge to heat the interior. It starts below 5 degrees celsius outside temperature.
When the heater is helping the car reaches operating temperature much fast then when it's not.
When the car stops and the eninge is stopped the heater runs for a while to clean itself. The heater has several different sensors and is TUV certified, if anything malfunctions it will stop.


Dennis de Held

Amulet Red 1.4 Tdi
 
There are still some two stroke diesels around but not generally in cars - too noisy and will not meet emissions limits. For the train spotters the Deltic was a two stroke diesel with 18 cylinders, 36 opposed pistons, three crankshafts and no (that is zero!) valves).

Motor car diesels are all four stroke, the same as petrol (The Otto cycle named after the original Mr Diesel???), the difference is the combustion process where diesel burns by being injected at high pressure into warmed (by being highly compressed) air instead of being injected though the inlet port and ignited by a spark (petrol engine). I believe that there are now some petrol engines using compression ignition now (Mitsubishi's GDI engines??) which are reputed to give gains over normal petrol cars. The noise relates more to the higher cylinder pressures (compression 1:18-20 rather than 1:8-12 for petrol) as the burn itself is slower for a diesel - I believe that is the reason they have lower red lines (4-5000 for the A2?). It is the higher cylinder pressure which gives the higher torque and that together with a more controlled burn which give the higher efficiencies.

Ian


2002 1.4 Petrol SE, silver with climate control.
Why are all the A2s in Lichfield are silver ? ? ?
 
quote:This week my TDI was -12 celsius and when it finished glowing I've started. Funny how diesel engines have a way of letting you know that they're not happy at all. It started allright but the noise was raw and I had to switch gears around 12/1300 rpm.
Click to expand...

During cold mornings (below 2.5°C), I get a really 'raw' noise at about 2000rpm accelerating, plus at any rev while deaccelerating. It seems to be more of a vibration noise (from the engine bay). I gut feeling is it may be related to the Webasto heater?

Any Ideas?

Kaine

p.s. Dennis : Congrats on the 300 posts!!! Hang on in there, we'll soon be up there with God, sorry I mean JD :D


----------------------------------------------------------
In the land of Mordor where the shadows lie
 
quote:
During cold mornings (below 2.5°C), I get a really 'raw' noise at about 2000rpm accelerating, plus at any rev while deaccelerating. It seems to be more of a vibration noise (from the engine bay). I gut feeling is it may be related to the Webasto heater?
Click to expand...
The webasto makes a humming noise, it's bit like a electric fan starting under the hood. When the volume of the radio is down I can hear the heater start and stop.
When you stop the car you can also hear a whining noise under the hood, that's the heater performing a cleaning cycle.
The raw noise (and feeling) is just the engine being unhappy. The first time I heard it I actually thought there was someting wrong witth the engine, but when it got warmer it stopped. I guess that when the engine is cold, it gets harder to ignite the fuel combined with the fact that the turbo isn't running at low revs. That must make it quite hard for the engine, so the mixture is altered and maybe even the injection time. That causes the raw noise and the low torque.

quote:
p.s. Dennis : Congrats on the 300 posts!!! Hang on in there, we'll soon be up there with God, sorry I mean JD :D
Click to expand...
Well I might reach his number of posts, but I'm afraid I'll never 'be up there with him'....
But does that mean I'll have to start making Tesco jokes too ??? Cause I haven't got the faintest idea what it is....

Dennis de Held

Amulet Red 1.4 Tdi
 
quote:Originally posted by speedfreak
Hello,
Call me paranoid (hey, its all the problems reported here
Click to expand...

Yes you're right about that but dont't let that get to you, the A2 also has many good things. It's just the fact that people never talk about or seek advice on things that function properly.
That and the fact that only the people who are contaminated with the A2 virus will go on the internet and talk to other A2-nauts about their cars. I bet that there are hundreds (maybe even thousands) happily drivers out there.



Dennis de Held

Amulet Red 1.4 Tdi
 
1. I usually wait for the yellow 'heater' sign to go out. I believe it doesn't harm to start an engine earlier. But in a colder weather it just wouldn't start, if I don't wait for it.

2. Some A2 TDIs are equipped with Webasto additional heater and some have just an electric heater. For example my car (1.2TDI) didn't have a Webasto originally. When the ECON-button is OFF, then the additional heater is in use. Anyhow this heater is only in use when the car is running.

It was a little bit colder here a week ago and then noticed that engine temperature doesn't come up to +60C at all (the lowest temperature in the meter). Not even after hours of driving and ECON-button OFF all the time. Engine just doesn't produce enough heat when it is around -30C. Cabin temperature is almost okay still in this weather, but rear side windows stay frozen. If the outside temperature is about -20C, or warmer, then the engine heats up eventually to the normal +90C.


With best regards,
Jones (A2 1.2TDI, no aircon)
 
My A2 1.4 TDI is standard equipped with the Wabasto heater. The heating light switches off after approx. 1 sec. And I don't even wait for it. My engine always starts smoothly, only at -10°C I hear some typical cold diesel clappering, but just very slightly. Perfect engine!!!

greetings,
Thierry
 
Dear All, My first message and I don't even own one of these little gems yet. It is being ordered today!! We are having a big problem with colour and leather?? Can't make up our minds. We like the denim blue of the A4 range.... Any way onto pre heaters and realy interesting stuff. My present 7 year old A4 110 tdi only gets warm after 15km. I am very interested in the webasto heaters. Do they warm the engine water and so get it up to temp faster or is it only the cabin heater. Can I get one in the UK (I live in Orkney, Scotland and it would be realy usefull.)

Torquil
Orkney
 
quote:Originally posted by Torquil

Dear All, My first message and I don't even own one of these little gems yet. It is being ordered today!! We are having a big problem with colour and leather?? Can't make up our minds. We like the denim blue of the A4 range.... Any way onto pre heaters and realy interesting stuff. My present 7 year old A4 110 tdi only gets warm after 15km. I am very interested in the webasto heaters. Do they warm the engine water and so get it up to temp faster or is it only the cabin heater. Can I get one in the UK (I live in Orkney, Scotland and it would be realy usefull.)

Torquil
Orkney
Click to expand...

Hi Torquil and welcome to the forum.

This must be your lucky day since all 1.4Tdi's are standard equipped with a webasto pre heater. The 1.2 Tdi's have electrical cabin heaters and the non Tdi's have nothing.
This is probably one of Audi's best kept secrets, they've certainy never told me.
The standard heater activates when the outside temp is below 5 or 6 degrees celsius and helps the engine to heat the coolfluid. There is no way to manually activate the standard heater. And when the CC is in ECON mode, it never starts since you want to be economically (and cold).
It is however quite simple to connect some relais, some pumps and a timer to the already builtin heater and then you have a timer (or remote) operated preheater.
This is something that you shouldn't attempt to do yourself unless you really know what you are doing, it took the webasto fitter three days to fit it into my A2.

Hope this answers your question !


Dennis de Held

Amulet Red 1.4 Tdi
 
Torquil,

Yes, it appears to be a fact of life that TDI’s seem to take so long to warm up in the cold weather. This I have found to be very disappointing because it does mean that short journeys are not healthy for the car. Moreover the fact that cold engines probably create the worst of wear situations is a matter that concerns me, and I don’t mind telling you that because of this I often find myself walking instead of getting the car out of the garage.

The ultimate solution to all of this is to fit a top specification “Webasto” heating system, which can be operated via a radio remote key/device – thus bringing about a situation where following activation the engine block and oil have gained good warmth before driving off. The best of these systems are certainly not cheap, and from memory we had one A2 owner on the forum from Norway who had this work carried out in Germany for about £900.

If you search around the internet specifically on Yank based VW forums you will find that many Americans make use of “pan” type electrical heaters. These are no more than flexible plate that is stuck to the underside of the oil sump, and then plugged into a power socket for a few hours – or overnight if the weather is really cold like minus 10F. These devices on cost around £30, so at least it’s a financially practical solution, however the big drawback is that firstly you need a garage, and secondly if say you drive to work then there is no way the car can be warmed up to come home 8 hours later.

In addition the American market makes much use of electrical heating devices that warm up the radiator fluid, which as a result apparently ends up warming the oil to some degree, and naturally making the car interior nice and cosy before driving off on a cold morning. The fact that they likewise need plugging into a power socket does restrict where it can be used.

If you read carefully what Dennis has done it is obvious that the A2’s existing heating system can be modified to some degree, and perhaps DH will come back and confirm what the cost of the modification was. The manufacturers “Webasto” have agents throughout the UK, and I figure these people are the best for the job.

I laugh that we suppose to currently enjoy the best of technologies, but it’s a nonsense really when 20 years ago I owned a petrol air cooled VW Passat which had a secondary petrol powered heater on a manual time switch. It did mean setting it for 15 minutes before going to work, or before coming home, but heavens it used to be like stepping inside a sauna. It was a fantastic piece of standard equipment.

Regards
John Disdale
 
John,

My TDi is equipped with the same modifications as the A2 from Norway. The standardheater is equipped with a fuel pump and a water pump to allow it to operate independantly from the engine. Furthermore there is a timer and a remote control unit fitted.

This is all because the TDi is a very economic engine, that's good for the environment ! And from what I read it's also good for your health :)

Dennis de Held

Amulet Red 1.4 Tdi
 
Dennis,

For Torquil’s benefit perhaps you could conform how much the modification cost you.

For my own interest how long do you have to use the “webasto” for (prior to driving off) in order to obtain a normal (or near normal) oil temperature ? Assuming say an air temperature of 35F.

Regards
John Disdale
 
Hi Dennis, John and the others from the windy north..its blowing about 60mph outside at the moment (90ish kph) and about 5oc

my poor old A4 has been out in this for the last 7 years!! I went away on a trip to New Zealand last month and when i came back the seats had a light mould growing on them...not very pretty.

I also drive to work and back in a cold and damp car for about 6+ months of the year. I have considered retro fitting a system to my A4 but alas lazyness!! I am also interested if all these system are effectively going to destroy the fantastic fuel economy of the A2?
If the system comes on at 5oc does it then go off when the engine is warm? Also there are have lots of days when it is 7oC!? here in Orkney
 
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