Saving weight by removing cooling fan shroud / assembly

I'm thinking of ways to reduce my TDI's weight, and was wondering about removing the cooling fans and their mounting from the radiator. In the 50K miles I've done in my 90hp TDI I don't think the fan has ever gone on, even on hot days in traffic. The temperature guage always stays exactly in the centre once the engine has warmed up.

I suspect the fan may never have switched on in the life of the car, so it seems like a good candidate for weight reduction.

Has anyone ever noticed if their cooling fan has activated?

They come on when the A/C is turned on.

My car doesn't have A/C . I'm in Europe, my TDI is one of these: http://en.wikipedia.org/wiki/Image:Seat_Ibiza_2_front_20071004.jpg
I don't think you have them in the US. I think the fact that it only has 90hp (AHU engine) may be a factor in its not getting hot.

mad_despot said:

My car doesn't have A/C . I'm in Europe, my TDI is one of these: http://en.wikipedia.org/wiki/Image:Seat_Ibiza_2_front_20071004.jpg
I don't think you have them in the US. I think the fact that it only has 90hp (AHU engine) may be a factor in its not getting hot.

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Still not a good idea and it does'nt weigh that much. If you're serious, rip out the carpet, door panels, replace the seats with racing buckets, lightweight wheels, no spare, etc....

I'm not quite that serious . I want to keep my car looking reasonably standard. So far I've just removed my spare wheel but I'm planning a mufflerectomy and / or a decat.

There are two fans (one is belt driven off the other) and the whole assembly looks as if it must weigh a fair few KGs. It's also right at the front of the car so losing it would be good for weight distribution.

You've taken out things that are trivial at best... You removed the spare but won't take out the back seats? You want to pull part of the cooling system but won't take out the carpet...

You need to decide whether your going to remove weight or push your luck when something goes wrong. Spares are carried for a reason, 30lb carpet isn't.

Well, I carry one of those puncture repair in a can things.

My question is, has anyone determined if their cooling fan has ever switched on, apart from if they use their A/C? Is it basically redundant in the lower powered TDIs without A/C?

One of your arguments that it isn't needed is that the tempuratue guage doesn't move. This is a marketing/engineering ploy.

It seems that as people get smarter and smarter, they tend to know less and less. This leads to people not knowing how a car works and the fact that the temperature guage will move up and down depending on the load on the engine.

So, since the marketing people didn't want people freaking out about the temperature guage going up and down, they had the engineers design the ECU so that it will know the correct temperature, but it will report a steady temperature to the person behind the wheel.

And you are using this as part of your logic to remove the fan.

So, the actual temperature varies a little but the guage remains steady as long as it's within range? I see, but even so, does the temperature ever rise enough for the cooling fan to switch on?

In the past I've been stuck in traffic on a hot day but never heard the fan. All diesels run very lean at tickover anyway, so my thinking is maybe they don't get hot enough. Perhaps a taxi driver would know, they often leave their engines running all the time - any taxi drivers out there?

My car is small / relatively light and it's the lowest powered TDI so perhaps least likely to get too hot.

It would appear your car has a loose nut between the steering wheel and the drivers seat.

Leave the fans on the car. VW knew where the car was to be sold and correctly equipped it for the local environment. Really!

Cheers and all that!

Bill

Maybe it's a quiet fan and you can't hear it over the engine noise. Get a tiny camera, sender/receiver, lights under the hood and a video display so yo can monitor the fan. This will tell you how often it comes on.

Is it legal to drive without clothes where you are? Are both headlights actually needed? How about all of that glass that just gets fogged up? When was your last BM? Lots of ways to shave off weight on race day.

> It would appear your car has a loose nut between the steering wheel and the drivers seat.

Well, I can't deny that!

Still want to know if the cooling fan ever actually gets used, I think I'm just going to have to experiment by disconnecting it and keeping an eye on the guage in traffic.

>Get a tiny camera, sender/receiver, lights under the hood and a video display so yo can monitor the fan.

Too difficult for me, but I suppose I could rig something up to detect if the fan switch ever turns on.

mad_despot said:

> It would appear your car has a loose nut between the steering wheel and the drivers seat.

Well, I can't deny that!

Still want to know if the cooling fan ever actually gets used, I think I'm just going to have to experiment by disconnecting it and keeping an eye on the guage in traffic.

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Hehe,
Glad you took that the way it was intended.

Remember, the stock temp guage is NOT a guage but an idiot light.
It shows normal (190?) even though the real temp may be from 165? to 210? at any given point in time.

Does your car have an OBDII port? If so, you can get a scan-guageII and read the REAL temp in real-time as well as many other things.

http://www.scangauge.com/

Bill

mad_despot said:

> It would appear your car has a loose nut between the steering wheel and the drivers seat.

Well, I can't deny that!

Still want to know if the cooling fan ever actually gets used, I think I'm just going to have to experiment by disconnecting it and keeping an eye on the guage in traffic.

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My car's cooling fans have turned on. Its been on hot summer days, 95+'F, stuck in a backup on the highway do to road work being done.

The OEM gauge is filtered to read 190' from about 170' to about 210'. So it isn't much better then a light. I take my Scangauge as being correct. When I see it go over 205' I have turned on the AC to have the fans run, and temp. comes back down.

From the Bentley manual for my 2004 Golf there is a dual temperature SENSOR ( two sensors ) near the cylinder head, current design is with green plastic, for the ECU and dash. There is also a dual temperature SWITCH ( two switches, each at a different temperature trip point ) in the radiator near the outlet hose going to the thermostat, ( cooled coolant ) for controlling the fans, low and high speed.

The first SWITCH goes on at 92-97'C ( 197.6-206.6'F ) and back off at 84-91'C ( 183.2-195.8'F ) for low speed fan, the second SWITCH goes on at 99-105'C ( 210.2-221'F ) and back off at 91-98'C ( 195.8-208.4'F ) for the high speed fan setting. The relay control module also cycles the fans on low speed with the AC.

So if the fan(s) don't go on when the temperature switch is at 221'F there is a problem. Hope this is of some help.

I do not like things running that hot at the radiator outlet, as hoses and other items do not live as long at these temps.

mctdi - thanks for that, very useful to know. Maybe the fans have gone on then, at least to low speed, without me noticing.

40X40 - yes, my heap does have an OBD port, I might try that Scanguage or something similar in view of what mctdi said - I might get VAG COM and monitor the temperature before deciding if removing the fans is a good idea.

RabbitGTI said:

Still not a good idea and it does'nt weigh that much. If you're serious, rip out the carpet, door panels, replace the seats with racing buckets, lightweight wheels, no spare, etc....

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i think it is illegal to drive without a spare in Europe/ UK

+1 on the scangauge.

Above 15MPH the fan probably never comes on anyway and with the fans gone, cooling airflow would be better. Added to that, Deisels produce very little heat at idle.

The only downside is that you would have to monitor the temp in heavy traffic and be prepared to pull over and turn the engine off if scangauge indicated you were overheating.................On cars without A/C, electric fans are allmost useless.

dayne66 said:

i think it is illegal to drive without a spare in Europe/ UK

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No, that can't be. The Eos in European trim does not come with a spare...

Ol'Rattler said:

+1 on the scangauge.

Above 15MPH the fan probably never comes on anyway and with the fans gone, cooling airflow would be better. Added to that, Deisels produce very little heat at idle.

The only downside is that you would have to monitor the temp in heavy traffic and be prepared to pull over and turn the engine off if scangauge indicated you were overheating.................On cars without A/C, electric fans are allmost useless.

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That's just what I was thinking.

You could also drain a bit of coolant, crankcase oil and transmission lub to save an additional amount of weight.

Really... what will you gain by removing the weight fan and shroud? I just don't see any benefit given the possible risk.