External pad-type of sump heater on a TDi - Is there a suitable mounting location on the sump?

audifan said:
In reality the electric auxiliary heater does help warm up the engine quicker but only slightly. This is due to the positioning of the electric heater below the heater matrix in the cabin. The air is blown by the fan into the cabin and also rises into the matrix putting some warmth into the coolant sytem however marginal.
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Are you sure? In the Lupo 3L the heater is after heat exchanger:


Page 46.

RAB
 
Rusty911 said:
That is a really good read: I hadn't realised just how deeply the 3L differs from the conventional cars :cool:
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Yes, it might look like a "normal" Lupo but it only shares about 20% of the parts! Even a different body (thinner but stronger steel) which it shared with the GTi and FSi. I don't think VW made much profit from it.

RAB
 
Calix are extremely common here, DEFA even more so. Which is the other reason I'd go DEFA.. you've then also got the internal socket available and a bunch of other stuff, like battery chargers...

But TBH, you don't need anything over and above a decent switch for the coolant heater. It will circulate in the block, so normally you'd have 40C or so across the entire block before starting. We used to run a 307 with the DEFA in the coolant, it was always warmer faster than the A2 where the element is just slapped onto the block. The Octavia version has three different variants - one is an actual sump heater.

- Bret
 
Following reading on this a couple of years ago and recent discussion with @dj_efk I have a Defa heater and wires coming in the next few days for my Tdi. We don't have an available garage but do have on-driveway parking for the cars, and being up here in Scotland on a proper cold morning, the engine is nowhere near able to contribute to the windscreen once it gets frosty without at least 15 minutes of enhanced idling. My solution to date has been to use a trick I discovered in the (unheated and largely uninsulated) boathouse at Vancouver Rowing Club 15 years ago to slow-cure or dry out boat repairs - a mains 60W incandescent bulb in a spring-clamp holder with a garden extension cable (from the garage & in the A2 at least, attached to a dashboard cupholder in the out-position) overnight - 1-2 of these (cup holder & the wee removable cubby behind the handbrake) along with a sheet of double-strength bubblewrap over the screen are enough to keep the cabin and windscreen above zero and minimise the defrosting needs (outdoors for me!) at 0600-0620 when my other half is getting ready for a 7am start with her 1.4i ... The Defa is for my Tdi which doesn't have the overnight 120W cabin heating so I am dependent on my own resources in the same time-span and this seems like a good parallel idea.
 
Ok I spoke with the Calix dealer and he thinks the immersion type sump heaters aren’t suitable for this application., as they have no thermostatic cut-out and hence will end up overheating the oil (I assume they’re designed for much bigger sumps).

So it’s back to the original idea, installing an external pad type of heater from a reputable brand such as Wolverine - Hence the original request: Can anyone advise if there is a place on the sump that is flat and not immediately next to something that could be adversely affected by the heat? Thanks in advance.

P.S. I appreciate the debates so far, I do know it isn’t worth it from a cost point of view - then again neither was the coolant heater, but now I’m in this far I think it would be interesting to add this idea into the setup.
 
RAB said:
If you've never seen it, how do you know that you've not already got a pre-heater? Unlikely maybe but..... I would recommend some time reading the manual (if you've got one)!

RAB
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The car is a pretty famous one in these circles - the two previous owners are club members.

@Special edition can confirm that no such pre-heating modification has been carried out already I’m sure.

I’m aware of the electric cabin heater element and how it works - the engine warmup time is the main objective.
 
bretti_kivi said:
Calix are extremely common here, DEFA even more so. Which is the other reason I'd go DEFA.. you've then also got the internal socket available and a bunch of other stuff, like battery chargers...

But TBH, you don't need anything over and above a decent switch for the coolant heater. It will circulate in the block, so normally you'd have 40C or so across the entire block before starting. We used to run a 307 with the DEFA in the coolant, it was always warmer faster than the A2 where the element is just slapped onto the block. The Octavia version has three different variants - one is an actual sump heater.

- Bret
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Hi Brett, yes Calix do all that stuff too, it doubles the cost of the parts to install and properly wire in their cabin heater, so not worth it for our climate - and their sump heater as already mentioned is too powerful for a car sump (150w and no thermostatic cutout when up to temperature).

I went with Calix as Defa don’t list the ATL engine and refused to suggest what kit would fit when I approached them - they said I could buy at my own risk! No thanks.

These external sump heaters are not too expensive - if there is nowhere to site one safely then so be it, but otherwise it would be an interesting experiment to measure the additional improvement in warm-up times would it not? I’m happy to try it and write it up.
 
audifan said:
@RAB No2 is the water matrix and No3 is the electric auxiliary heater.

evaporator housing; air distribution housing; evap... Audi A2 (A2) 2003 year Audi EUROPA 820010

evaporator housing<br/>air distribution housing<br/>evaporator<br/>fan Audi A2 (A2) 2003 year Audi EUROPA 820010 spare parts
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You may well be right but I would advise against using something derived from Etka as a poor man's workshop manual. That way you may come to believe that ANY, AMF, BHC and ATL motors are all 4 pot!

RAB
 
So latest thinking is I’ve landed back on external silicone pad heaters; assuming there is a location on the outside of the sump where such a device would not damage anything immediately close by, then this company will make an inexpensive custom shape and specification heater pad with a built-in thermostat.

All I need is a location, I may get my garage to assist.
 
dj_efk said:
So latest thinking is I’ve landed back on external silicone pad heaters; assuming there is a location on the outside of the sump where such a device would not damage anything immediately close by, then this company will make an inexpensive custom shape and specification heater pad with a built-in thermostat.

All I need is a location, I may get my garage to assist.
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Just struck me the location of a heater on any of the four vertical sides of the sump is restricted really to the depth of the settled oil which is what 45mm(???), which leaves only the base. How much room between the the sump and the undertray?

Andy
 
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I'm sure it's been logged with the guys on the German forum, they tend to use Hotfrogs.
dj_efk said:
Hi Brett, yes Calix do all that stuff too, it doubles the cost of the parts to install and properly wire in their cabin heater, so not worth it for our climate - and their sump heater as already mentioned is too powerful for a car sump (150w and no thermostatic cutout when up to temperature).

I went with Calix as Defa don’t list the ATL engine and refused to suggest what kit would fit when I approached them - they said I could buy at my own risk! No thanks.

These external sump heaters are not too expensive - if there is nowhere to site one safely then so be it, but otherwise it would be an interesting experiment to measure the additional improvement in warm-up times would it not? I’m happy to try it and write it up.
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I would go check the German site, there are a bunch of Defa and Hotfrog users over there, including ATL drivers. As said, the additional benefit of a sump pad if you've already got a coolant heater is going to be minimal. Especially on the base of the sump, you're adding in another couple of hundred watts, but the coolant heater is also going to reach the rest of the block. Experience with the 307 one really was better than a heater on the block.

From the Octy experience, the Webasto is a very powerful tool to make sure that even in extreme temperatures, things are toasty pretty quickly; but you're likely to lose heat pretty quickly when moving. My Petrol couldn't keep 21C internally at -25 ambient and 100km/h. The Octy drops back below 50C as soon as you hit the motorway in winter (below zero) and takes an age to return.

- Bret
 
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