Another Aux Heater Question

[rodders]

just got another mk2 sharan tdi...the aux heater the one under pass floor,the pipes under the bus get hot,controls above pass rear door are on & the center button on console for rear heater lit up,but no heater noise or anything,no smoke jet noise at all,all fuses still there,no vag com is this a dead heater or what,or would the glow plug do this.iv sat there as long as i could no drink just the kids,not enough mins in the day...so ill understand if no one replies as you have heard this before,all the threads or posts whatever have all got smoke,any pointers ,anyone in wirral area with a vag com to see if any codes are there...

[bofus]

Sounds familiar to mine, after a bit a looking around...someone has removed the Aux heater booster. The rear internal heater is still there but the underfloor booster has been removed and the heater pipes linked together!!!

 

Gav

[marinabrid]

first , give the heater a tap with a rubber hammer , it may burst into life. if not check the metering pump wires are intact as they rot through. its in front of the fuel tank. it worked on ours 4 years ago when we got it. if no joy, bridge the sensor with a mini fuse , its located on the n/s wiper linkage under the bonnet. if no joy. you may consider fitting a new glow plug. be prepared for a long job as the screw rust up. the plugs you can get form gsf car parts. beru GH001 around

[ianyerman]

what does the sensor look like?

[marinabrid]

sensor is a small round object size of a thumb end . sits in a small clip that is attached to the passender side wiper linkage. easier to see if you remove the long pad panal under the wiper motor

[zeuren]

I just took the fuse out over a year ago = no further problems

[Mirez]

I just took the fuse out over a year ago = no further problems

 

 

Just the significant increase in engine wear as the car now struggles to warm up... no further problems - yet.

[seatkid]

I just took the fuse out over a year ago = no further problems

Just the significant increase in engine wear as the car now struggles to warm up... no further problems - yet.

Nonsense - you're just scaremongering Mirez!

[Mirez]

Nonsence youself! Most engine wear occurs when a car is cold- FACT. If the car takes a further, say 15 minutes, to warm up then thats 15 minutes more additional wear put on to the engine - call it what you want but VW/Ford arn't there to loose money, if they didn't need to fit it they wouldn't have!!!

[RADIOTWO]

Nonsence youself! Most engine wear occurs when a car is cold- FACT. If the car takes a further, say 15 minutes, to warm up then thats 15 minutes more additional wear put on to the engine - call it what you want but VW/Ford arn't there to loose money, if they didn't need to fit it they wouldn't have!!!

It Just goes to show what you know about engines, the idea for the Aux Heater is to get you warm quicker and not the engine !

 

what about the hundreds of other cars out there that don't have these heaters?

 

Radiotwo

Edited November 28, 2008 by RADIOTWO

[Mirez]

Incorrect. The ONLY reason for the aux heater is that it enables the engine to achieve operating temperature quickly. Now granted as a result, on these cars, cabin temperature is greatly influenced but there are many cheaper and more effienct options they would have gone with if its sole purpose was to do that.

 

Your argument looses further strength when you remember its on the COOLENT line. Any heat added to this circuit will naturally boost coolent temperature and therefore lead to an increase in engine temperature- its not rocket science old boy, the laws of physics don't change! The VW TDI is also renowned (in engineering circles - guess you dont hold a doctorate in engineering? :rolleyes: ) for being so efficient it CAN struggle to reach teperature. With the extra pipework and size of the cabin effiency would have been compromised yet further so whilst your argument has some merit you have missed the concept entirely. Maybe you should do a little research online before you wade in...

[sepulchrave]

Strong words indeed.....

 

However, I maintain that the most significant factor in engine wear characteristics is the temperature, pressure and condition of the oil since metal to metal contact does not occur.

The ambient temperature of the large lumps of metal in which the moving components are housed is frankly of little importance.

I'd be EXTREMELY surprised if mean combustion chamber temperature values deviated significantly from the norm, after all it's only really the pistons which expand when hot which is why high mileage engines can burn oil when cold, I don't see how wear can be an issue because these clearances are larger for longer.

Fast warmup is desirable from the viewpoint of passenger comfort and emissions/fuel consumption, but as long as you have good oil pressure available quickly then wear will really not be an issue.

 

A Doctorate simply means you know a staggering amount about a tiny and possibly obscure area loosely grouped under the umbrella of ENGINEERING, my mate also has a PhD in engineering from Strathclyde University and his thesis was about the work of John Logie Baird, an area which most reasonable people would call HISTORY.

 

So calm down Mirez and think it through before deriding others contributions and watch your spelling or this could get bloody!

 

I'm with RADIOTWO and SK for now, but I know there's more....

[Mirez]

See this is why forums are so much fun, because everyone thinks what they say matters.

 

Firstly let me assure you I could not be calmer, infact I'm rather amused since some of the arguments seem now to be down to personal comments but in conclusion, whilst my work involves engine testing, durability and destruction, I'm happy to sit back and not argue further points on the subject. I'll simply let those that believe overall block temperature has little to do with engine wear carry right on. :D :D

 

Smile all :rolleyes:

[bofus]

As someone who doesn't have a booster heater on their TDI .....I can indeed confirm that the temperature does indeed struggle to rise on any day when the temp is low.

What I have noticed when the temp is below 5C is the temp actually goes DOWN when the engine is idling, the level it goes down is dependent on the demands of the internal heaters (obvious really).

 

I've had diesels for the last 10 yrs or so, never seen temps go down after reaching normal op temp. even when in very cold (-30 climes), even an old Vx diesel with a dicky stat used to eventually warm up.

 

So it is either a very efficient engine OR the unlagged heater pipes under the floor loose as much heat as a normal radiator.

 

Just to add some more, even towing a Caravan in hilly areas in 30C heat this year, the engine temp never went above 90C...now that is a first for any car i have owned

 

Gav

[RADIOTWO]

Incorrect. The ONLY reason for the aux heater is that it enables the engine to achieve operating temperature quickly.

 

I thought the Thermostat was to let the engine warm up quicker, I was under the impresion the aux heater was as it says a

extra heater to keep heat in the car when the outside temprature is very cold.

 

it just gives heat when the car is ticking over, because if you leave a diesel just ticking over it will get cooler and cooler, so

you need some other device to keep heat in the heating system

 

Radiotwo

[sepulchrave]

...So it is either a very efficient engine OR the unlagged heater pipes under the floor loose as much heat as a normal radiator.

 

It IS a very thermally efficient engine (all Diesels are), but the major factor in cold warmup is that there are two large heater matrices trying to fill a very large van sized interior with warm air and consequently acting just like extra radiators, hence the auxilliary heater to boost heat flow into the system during warmup. This issue is particular to large Diesel MPV's. Minibuses and Coaches have it even tougher.

 

If you removed both heater matrices and the associated pipework then warmup would happen very quickly since the radiator is sized to suit the engines operating charactreristics independently of the passenger heating system.