Pre Heaters:
I understand the VW touran is fitted with one as standard? any one confimr this?
How do they work, are they working all the time its below x degrees?
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RF - currently 1 Renault short of a family
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Pre Heaters: I understand the VW touran is fitted with one as standard? any one confimr this? How do they work, are they working all the time its below x degrees? -- RF - currently 1 Renault short of a family
Different kind of pre-heater...
The heater the posters are referring to above are those which warm the engine to improve cold start, fuel economy and reduce engine wear.
The pre-heat in the Touran and many other VAG TDI engined cars is a heater to warm the coolant before it passes through the heater matrix when the engine is stone cold, so that on a frosty morning the heater works quicker.
It's a real bonus on a TDi engine, because they take forever to warm up. My old Mk4 Golf TDI used to take 5 miles plus before the air blew warm. My new A4 is warm pretty much straight away :-)
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One of the options for L-R products is a diesel powered heater, which can be set on a timer to heat both the engine and the interior using the coolant circulation, ala Kenlowe. This one will work in the middle of nowhere!
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Mates old BT Transit came with one, Kenlowe I think. It ran off the diesel, no mains needed. Made a hell of a racket though.
The new Vauxhall vans don't have them.
Worth keeping an eye out at auction if you're after a van with all the kit cheap. Just choose carefully.
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There are a few types or fuelled pre-heaters, notably from Webasto & Eberspacher, the "best" and most complex are either diesel or petrol powered mini boilers that work in basically the same way as a domestic central heating boiler. I just fitted a webasto DBW 46 to an Audi A6 2.5 TDI and it really has transformed using the car from cold.
My journey to work is about 7 miles and the heater would just start to work after about 7 miles (tepid), but the engine was still below the 50c mark on the gauge. An unfortunate downside to Diesel engines because they are just so much more heat efficient than petrol engines.
Fitting it wasn't basic diy and quite a lot of work considering it's a generic item and not desiged to fit my car, but for me at least well worth the effort, (and cost). The webasto range has newer more efficient models now, (Thermo top), and such features availble as remote start, and and modem so you can also phone the heater to start it!, (handy if you are on an often delayed train).
Both types mentoned above heat & circulate the coolant, and depending on how they are installed will heat the interior and the engine to virtually normal operating temps on about 1/4 the diesel than running the engine would consume. Other more simpler types often used in vans and lorries burn diesel to make hot air blower, (can be noisy as mentioned).
I have a question, was wondering what the legalities of running the heater in my car on red diesel would be. At present I've modified the pick up in the tank, (the pre-heater takes fuel from a separate suction about 1 inch above the standard engine supply to avoid it ever running the tank dry). If I were to fit say a 20 litre additional tank under the car that was not connected to the main tank, could I fill this with red diesel? I wouldn't be using it for driving the car just Pre-heating it so would that come under road use??
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"The pre-heat in the Touran and many other VAG TDI engined cars is a heater to warm the coolant before it passes through the heater matrix when the engine is stone cold, so that on a frosty morning the heater works quicker."
Also found on Xantia HDi 110 - not sure if all models or just Exclusive
Phil
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Also found on Xantia HDi 110 - not sure if all models or just Exclusive
Interesting...can you get some pics/info? Wouldn't mind trying to fit this to my 306. Takes an age to warm up in the morning!
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Road use
well, you're clearly not using on the road. But if a policeman were to investigate your car, it:
1, would have red stain in the injectors
2, would have a tank full of red diesel
3, would look as though you were avoiding duty.
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Well I suppose I'll have to get the official wording and see how is laid out because if it says road use then technically using the heater while that car is on the road could fall under the legal definition.
just seems crazy burning expensive, (over taxed), white diesel, if I could legally use cheaper red as I intend to use the pre heater all year round to increase engine life, (especially as it's now done over 180,000 miles)
Thanks for the input, to clarify....
1. The Red diesel would never go through the engines injectors or any part of the cars fuel system. it is only burnt by the pre-heater in it's own sealed combustion chamber totally separate from the cars fuel & exhaust systems..
2. Yes the additional tank would have red diesel, but in no way connected to the "white diesel tank". One outlet from the additional tank with red would go directly to the pre-heaters supply pump.
3.Yes it could be misconstrued, but would be nice to know what the legalities are as I'd be able to prove if need be it wasn't fuel the car was running / driving on.
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By no means fully investigated yet, but an excerpt from the HM Customs & Excise site seems to indicate that using red for my heater set up as previously described is ok:-
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4. General questions about rebated fuels
4.2 Does any separate machinery on my road vehicle also have to use fully duty paid fuel?
You need not use fully duty paid fuel for your separate machinery so long as it has its own fuel supply and engine separate from the vehicle?s fuel supply and engine. You must use fully duty paid fuel if the vehicle?s fuel supply OR engine drive the separate machinery. If your vehicle is allowed under section 8 to use oil other than fully duty paid fuel as fuel, you can similarly fuel any separate machinery on it.
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customs.hmrc.gov.uk/channelsPortalWebApp/channelsP...5
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It's a real bonus on a TDi engine, because they take forever to warm up.
I know it's not relevant to the thread but it's interesting to hear you admit this, because one of the reasons that I won't buy a diesel is the deleterious effect on heater performance of the long engine (and hence also coolant) warm-up time.
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L\'escargot.
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Bladerunner - don't know how old your Audi is, but I'm pretty sure they have additional electric heaters fitted now, albeit they only work when the engine is running. However there is another thread www.honestjohn.co.uk/forum/post/index.htm?t=36725&...e that mentions Passat and A4 diesels that blow out warm air after 20-30 seconds. I think Ford also use this system on their diesels.
My MB C270CDi has a setting which somehow allows the air-conditioning compressor to assist engine warm-up on cold days and that gets warm pretty quickly.
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My MB C270CDi has a setting which somehow allows the air-conditioning compressor to assist engine warm-up on cold days and that gets warm pretty quickly.
Wouldn't that just be the extra load on the engine? Not that I'd mind being proved wrong on this one...sounds interesting.
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>> My MB C270CDi has a setting which somehow allows the air-conditioning >> compressor to assist engine warm-up on cold days and that gets >> warm pretty quickly. Wouldn't that just be the extra load on the engine? Not that I'd mind being proved wrong on this one...sounds interesting.
Yes, I'm sure it must be, and the fuel consumption does seem to have increased since the colder weather - indicated average 44MPG on long runs that were 48MPG (still with the a/c on) during the summer.
However I noticed that my wife's Jazz fuel consumption has increased too in the colder weather. That would reliably indicate 50MPG a few wks ago, now it's only 44MPG.
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Good point, surely car aircon could be designed to be 'reversed' to heat the car?
Plenty of fixed (building) airconditioners now heat as well as cool simply by reversing the refrigerant direction, and are very energy efficient, typically only requiring 25% of the heat output they provide in electricity consumption.
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Just had the heater unit out to replace the matrix, (not because it was faulty as such, but blocked due to previous owner using just water in the cooling system... muppet!), and found it has an electric additional heater fitted.
This was obviously faulty, but I wasn't aware they were fitted to cars as "old" as mine. I'd seen additional heater mentioned in the Haynes manual and thought they were referring to the webasto unit which was also an option on my car.. at least in Europe.
In replacing the matrix I left the additional electric heater out and wont be replacing it for two reasons:-
1. I have the webasto diesel powered pre-heater as mentioned, (which works far better now with a new heater matrix)
2. Audi want £1500.00 + VAT for a new electric heater... ROTFLMAO
for those that want to view the internally diamond encrusted / gold plated item I've included some image links
www.zfz.com/pictures/ebay/heater_01.jpg
www.zfz.com/pictures/ebay/heater_02.jpg
www.zfz.com/pictures/ebay/heater_03.jpg
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Please note I'm in no way affilated with Pepsi, empty can was included for size only ;-)
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It maybe annoying but appreciate the reason the engine / heater in diesel takes longer to produce heat isn't a fault, but the fact they are not wasting so much energy from the fuel they are burning making waste heat. Driven correctly diesels are far more economical than an equivalent petrol engine, it's just testers and most people that have only owned petrol cars drive them in the same way using too many revs. I very rarely need to go over 2000 rpm in mine, and mostly around 1200 to 1500 rpm, (six speed) I get an average of 52mpg with mostly A road, town and a little M way use. (not bad for a big estate car).
Yes mine is the older Audi 100 shape A6, 5 cylinder 140bhp.
Electric heater assisters are an answer to quicker heater output in the newer cars but you can't beat a pre-heater, because it will pre warm the interior, defrost the windows and warm the engine, (cold starts are where the majority of wear & damage occurs), the worst par of a cold car for me was the steering wheel, (some newer cars have heated wheels,but oddly they are not very reliable / long lasting from what I've read?)
Most of the higher end cars can have webasto heaters as an option, but the cost is often far more than retro fitting one.
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I wouldnt have thought the diesel powered ones would use enough fuel for it to be an issue, to make it worthwhile using red diesel? I thought they were talking about banning red diesel anyway?
My Saab 9-3 TiD has an engine auxiliary heater (diesel powered)fitted as standard. It automatically starts with the ignition if the outside temperature is below 5'C, and the coolant temperature is below 75'C.
It makes a noise like a mini jet engine under the bonnet, and you sometimes notice a different exhaust smell coming from under the car.
You can buy a kit from Saab so you can time it to start before you get in the car, but its around £200 so I cant be bothered.
At around 0'C it seems to warm the car a bit quicker, but not as quick as I expected it would. I'm told they are more effective in the colder weather they get in Sweden.
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It's a real bonus on a TDi engine, because they take forever to warm up.
>>I know it's not relevant to the thread but it's interesting >>to hear you admit this, because one of the reasons that I >>won't buy a diesel is the deleterious effect on heater >>performance of the long engine (and hence also coolant) warm->>up time.
>>--
>>L'escargot.
I think it's pretty much widely accepted that Diesel engines take longer to warm up than petrol.
That said, with the auxilliary heaters which are fitted as standard to a large number of cars nowadays, it's not an issue. My TDI is blowing hot air out within a minute of start-up on a frosty morning - even quicker than a petrol engine.
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That said, with the auxilliary heaters which are fitted as standard to a large number of cars nowadays, it's not an issue. My TDI is blowing hot air out within a minute of start-up on a frosty morning - even quicker than a petrol engine.
I didn't know that. Obviously I'm behind the times diesel-wise. How do they work? Electricity or fuel-burning?
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L\'escargot.
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In response to Cardew, usage is a 40-mile round trip almost every day, interspersed with longer trips but very few shorter trips. This has been the pattern for the past several years and more.
I guess it exposes how heavy fuel consumption can be in those first few miles. I noticed the difference immediately, but after the initial excitement and some sober reflection I was not expecting a marked change in fuel consumption.
However, the numbers are there -- cumulative and therefore more reliable than a rolling average -- and I can't deny them. I'm also noticing 30+ mpg on an individual tankful, which I never saw before the pre-heater was installed.
The latest fill-up has seen the cumulative average rise to 28.01 mpg. I always use Optimax (down to 90.9 at Shell Chiswell St Albans, with premium down to 84.9).
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I think most of them are electric. In it's most simplistic terms, it's a coiled heater element wrapped around the water hose just before water reaches the heater matrix. I'm sure it's a lot more complex than that (!), but that's the general idea.
I believe there are also some manufacturers who fit actual fuel burning heaters - not sure if this is standard fit or optional extra.
Personally I have an Audi with one of the electric elements and it works a treat. It will only run with the engine running, so you don't scupper your battery. It can be turned off on the climate control by pressing the ECON button (which also turns aircon off).
Not noticed any drop in fuel economy by using it, but apparently it can affect it slightly. Presumably the fuel burning ones are even more thirsty.
Doesn't seem to make the temperature gauge move any quicker though, so suspect the warmed coolant is recirculated through the heater matrix rather than being allowed to enter the engine...
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Red diesel is currently 50p/litre compared to 12p in 2001 so not as much saving as it would have been. Probably not worth the hassle on cost grounds, could also see an MOT station giving grief over the safety of an additional fuel tank.
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Bit of topic drift here, but the VW 411 had a petrol stove to supplement its weak heater, and the top models had a timer so that the device would come on before you left your house in the Hamburg suburbs to drive to work through the snow.
My impression was that these things stopped working early and were never repaired. The one in my 411 Variant certainly didn't work, just as well because its fuel consumption was 28 mpg at all speeds. Quite a nice car though with a solid feel if you didn't mind the nose-up stance when there was no luggage in the huge front boot.
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I should have added: the bigger capacity VW flat fours especially the 1700cc one in the 411 had weak bottom ends, and a lot of 411s had rattly second-hand engines.
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Wow -- talk of a VW 4ll! I had a 411LE Variant as a company car in the early 1970s. It was great in a straight line and predictable around bends, but a nightmare on motorways in strong crosswinds -- unless, like me, you put a couple of hundredweight in the front boot, which in my case was boxes of books. The brakes were awful, the gear change the proverbial pudding-basin feel, but it was capacious and not short on elegance for its time.
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Mine was an LE as well, very secondhand. When I bought it the front boot cover was dogeared having at some point come open at speed. I bought a secondhand navy blue one from a later model, which made the white car look like a German police car. Anyway something about it seemed to attract the traffic and other police.
I don't know about elegant but it was made of thick metal and the distant thrum of the engine sounded good. It was supposed to be able to cruise indefinitely flat out in top at 96mph, was comfortable and rode and handled quite well once the dampers had been replaced, but used to shake loose its complicated and expensive exhaust system, eating the copper rings that served as manifold gaskets and sometimes giving quite decently loud backfires. I liked it (I like Skoda Estelles too) but packed it in when the final drive went.
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Wow! somebody else remembers the 412le. My dad had a new 73 variant, essentialy a estate car with 2 boots
I too remember the petrol heater, very good long distance cruser. Dad's only comment on handling was it handled the best when he had a load of tiles in the front boot!
Have not seen one for many years guess the've all rusted away
Was this the ultimate development of VW's aircooled cars?
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Red diesel is currently 50p/litre compared to 12p in 2001 so not as much saving as it would have been. Probably not worth the hassle on cost grounds, could also see an MOT station giving grief over the safety of an additional fuel tank.
I did some very basic calcs and it worked out about £150 a year to use it twice a day for 300 days on duty paid diesel.
I must admit, (I wasn't aware Golden Brown had got his tax greedy paws on Red as well), last time I bought some was probably 1998 for a JCB.
I might still do it once I confirm the legality as £50 to £70 saving a year may not be much but it'll give me ten times the satisfaction knowing this Tax happy government wont be getting it, and it can go towards my ever increasing Council Tax extortion..
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Hi,
I bought a used 1999 model Saab 9-3 TiD a few months back. I was reading through the handbook recently & was surprised to read about the diesel powered auxillary heater that switches in when temp is below 5C.
Overall I'm really impressed with the car but my problem is the weather just lately has been well below 5C and I'm not sure this aux heater is working properly.
Have you got any tips on how I can check the device is operating correctly plse? Also, where is it & what does it look like under the bonnet plse?
I find I can't get a Haynes Manual for a 9-3....what do other people use for diy maintenance if there isn't a Haynes manual?
As a complete newcomer to Saabs any help/advice you can give will be very gratefully accepted.
Thanks
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Can never understand why Audi, MB etc don?t offer the pre-heater option to the UK market. Have they never heard of the Scottish winter. ? From November to March it?s often necessary to thoroughly de-ice the car before it can be used. Pre-heat would be bliss.
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often necessary to thoroughly de-ice the car before it can be used. Pre-heat would be bliss.
I find a mains powered fan heater in the car for 10 - 15 minutes when it is serously cold is adequate to de-ice and warm the car. For the odd few days it is required (even in Scotland, its not Siberia) it is an easier option. I must admit I only use this method on the car that is not in the garage. How long before we can start aircon threads? Mine is working, it was dripping water yesterday, (in Scotland).
Edited by Old Navy on 28/02/2009 at 11:00
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Have you got any tips on how I can check the device is operating correctly plse? Also, where is it & what does it look like under the bonnet plse? I find I can't get a Haynes Manual for a 9-3....what do other people use for diy maintenance if there isn't a Haynes manual? As a complete newcomer to Saabs any help/advice you can give will be very gratefully accepted. Thanks
The Saab 9-3 auxiliary engine heater is mounted high on the engine bay bulkhead (just right of centre when looking from the front). Its a metal box about 9" long with a rounded underside and a plastic top. It has 2 rubber heater hoses coming out of the top.
For it to work it needs to be below 5'c, coolant temp. needs to be below 75'c, and there needs to be more than 10 litres of fuel in the tank (ie. wont work if low fuel light is on.)
To tell its working there should be a slightly acrid exhaust smell drifting up from under the car, and there should be a muted roaring noise coming from the heater (can hear it from within the car).
It can be de-activated by a service technician, so if not working, this may have been requested by a previous owner.
To be honest, the one on mine doesnt seem to make it warm up much faster; I was advised they work better in the colder temps. they get in Sweden.
I have a Saab 900 Haynes manual which covers a lot of stuff on the 9-3, but not everything, and not the diesel engine. For maintenance advice see the forum at www.saabscene.com.
HTH,
Rich
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