air shroud thermostat

taurine Learner Dubber

7 posts · joined Nov 2006 · 13 Nov 2006, 8:29 pm

#555051

Does anyone know much about the thermostat on a bug. Is it possible to simply remove the levers etc from the shroudand simply allow full time air flow to the fan? Idont drive the bug in the cold so just curious if this is possible ?:beer

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 13 Nov 2006, 9:57 pm

#555090

im surprised u still have one fitted

most ppl rip them off during rebuilds, so most of the vws getting around dont have them anymore and the ones that do very few still have working thermostats

the thermostats are almost impossible to get now as they are a NLA part and good 2nd hand ones are rare

even if ur thermostat is dead a few ppl say its agood idea to leave the flaps in as they direct air to the heads

but i'm abit sceptical on this as when they are fully open they are perfectly vertical so it makes no differnce if they are there or not

ive got a working setup on my bug only coz i got a perfect thermostat off ebay but even in the middle of winter it doesnt make much difference about 2 mins and its fully open

they were designed for snow temps in germany

-Joel

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 13 Nov 2006, 10:08 pm

#555094

I've seen those thermo jobbies on maybe three engines in 20 years.. you'll be fine without them

Pay your debts, CxxT

taurine Learner Dubber

7 posts · joined Nov 2006 · 13 Nov 2006, 10:11 pm

#555095

Many thanks. Thought was probably the case as its for a convertible that only gets driven in warm weather !😊😊

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 13 Nov 2006, 10:23 pm

#555101

Hi,
Most VW Mechanics say the flaps should be left in, as they do direct the air
to where it should go..
they do just point down as You have said,
but without them being there the air can go where it wants to..
I agree...
I bought a new thermostat kit from the USA and have fitted everything except the thermostat itself..
it does get cold here in the winter, so I will fit the thermostat then...
also because I run My engine lid open at the top, the engine would tend to run a bit cool in the winter...

Do You want to know what happened to all the thermostats?
At the first service the VW Mechanics were instructed to take them out and chuck them away...
same thing happened in parts of the USA too..
so, most engines are doing without them...
but with temps below zero in winter, it has to better for the engine...

cheers

Lee - 68autobug - Scone.

http://community.webshots.com/user/vw68autobug

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- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

taurine Learner Dubber

7 posts · joined Nov 2006 · 13 Nov 2006, 10:39 pm

#555104

Hmmm interesting. My main worry was if I kept the flaps in without the thermostat they might inadvertently end up in a closed position at some point and cook the engine....assume if the connecting rod is removed that links the flaps then this cant happen?:beer

ctefeh Wolfsburg Wizard

479 posts · joined Apr 2005 · 14 Nov 2006, 8:53 am

#555187

Taurine,
The genuine VW ones fail in the "open" position, so no probs.

Ctefeh

Purple Martin Fahrvergnugen

913 posts · joined Feb 2003 · 14 Nov 2006, 10:07 am

#555215

There is a very good reason for leaving them in: they allow the engine to warm up quickly to normal operating temperature, which is important for getting the oil flowing properly. If yours is missing then your engine takes a long time to reach normal operating temperature, and therefore it is suffering from increased wear. Bottom line is the thermostat and flaps make your engine last longer.

1959 red & white Beetle
1975 Kombi camper

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 14 Nov 2006, 11:11 am

#555223

Make sure the spring is still attached to the bar at the back of the fan housing...
the spring will keep the flaps open all the time...
make sure you have little circlips [e type] holding the shafts to the bar.. or some VW type round clips..
I have had 3 different clips on the shafts... none fell off,
but during My pulling the engine out a few times and repainting the fan shroud etc.. I didn't like the wire clips,
the e type circlips were Ok and the round push on, never come off clips should be the best...

If You don't have the spring, just use any spring that will pull the flaps open all the time...
if you don't have the flat shaped bar that holds all the flaps open, just clean the shafts from the flaps so they are very clean and apply some silastic to them...
I did this with mine...
then I found a bar and spring, and had to remove the silastic!!
and now they are attached to the rod poking underneath the engine waiting to be attached to a new thermostat..
with the spring keeping the flaps open all the time...

cheers

Lee

http://community.webshots.com/user/vw68autobug

[ Edited on 14-11-2006 by 68AutoBug ]

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taurine Learner Dubber

7 posts · joined Nov 2006 · 14 Nov 2006, 3:48 pm

#555287

hi folks, thanks for all the replies. Looks like I will keep the flaps in. The thermostat is long gone but the bar and spring are still there and 3 of the 4 clis were attached so Ive made a new clip and I've tested it a few times and it positively pulls flaps to the open position and they stay there so all is well! :beer:beer

oval TOFU Bitte, ein Bit!

2,946 posts · joined Jul 2003 · 15 Nov 2006, 10:01 am

#555491

68AutoBug wrote:Do You want to know what happened to all the thermostats?
At the first service the VW Mechanics were instructed to take them out and chuck them away...
same thing happened in parts of the USA too..

Any idea why this was done, Lee?

...and Robert's ya father's brother...

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 15 Nov 2006, 4:34 pm

#555586

everyone reckoned they werent needed in average climates
only in snowy germany like i said b4

i have seen an engine fried by faulty thermostat flaps
as usual the thermostat had long since given up which is fine but over the years the vibration wore the hole the return spring goes thro bigger and bigger till it finally wore all the way thro and they fell shut

i took a few pics a while back when i put them back on my motor
but even in the middle of winter ive noticd no difference what so ever
its fully open with in about 3 mins
and it only regulates flow to the cyinders and heads not the oil cooler so the oil is always being cooled

this spring must be in good condition and the hole in the rod and tinware in good nick or ur in big trouble

the stats on the left are all buggerd the one on the right all compressed is good

-Joel

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 15 Nov 2006, 7:43 pm

#555645

Hi Joel,
Well You have more thermostats than most people have ever seen...
I will admit that the thermostat , bar and spring wasn't really made to last long time, and they don't really look like they were engineered to last..
no bushes for the bar or flap shafts, the hole for the spring in the fan shroud wore away, if the spring didn't wear thru first.. and the most important part, the thermostat was held on with one bolt...

The oil doesn't go thru the oil cooler all the time...
I was just reading My bentley manual, and it shows the 3 positions of the oil pressure valve...
very intersesting...

I can also remember reading an Article by Larry Perkins who Rallied Beetles in Car Rallies years ago, and He said "VW spent a lot of money on inventing the Beetles thermostat, so they should be left in place"

I also know many people who discarded their thermostat flaps years ago, and the engines don't seem to have suffered without them...

cheers

Lee Noonan

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

helbus Administrator Mad fabricator, paint and body

7,386 posts · joined Sep 2002 · 15 Nov 2006, 8:16 pm

#555654

Did the last of the Mexican Beetles run them? (thermostats)

EJ22 into Bay Microbus - Finished project build thread- click on this spot here for info

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 15 Nov 2006, 9:46 pm

#555703

68AutoBug wrote:Hi Joel,
Well You have more thermostats than most people have ever seen...

LOL i've got a bit of a noahs arc of vw parts thing happenign cept ive about 10 of everything...
i had toyed with the idea of resealing them cept i;ve yet to find out exactly what the fluid inside is

helbus the mexican ones do have them but they are totally different design and very poor qaulity from what i hear on shoptalk
heard a few horror stories about them

PJMS Learner Dubber

8 posts · joined Jul 2006 · 13 Dec 2006, 12:44 pm

#557356

...the mexican ones do have them but they are totally different design and very poor qaulity from what i hear on shoptalk...

Those are not Mexican thermostats, but Brazilian and only used as replacements for a few years. They have been discontinued, probably because they were completely unsuited to the VW engine and would fail in the closed position (a modified watercooled unit).

The Mexican fuel injected Bugs from 1993-2004 did not use thermostats. The reason for this was because the engine management sytem could actually control warm up just as effectively as the thermo itself. So, there was no point having two systems doing the same job! The same thing happened in Brazil when the Type 2 changed over to the same Digifant system. In fact there was a period when VW Brazil were producing both carb and FI models; the carb version had thermos and the FI didn't.

The thermostats will work in all weather conditions, but c learly, the engine will warm up faster in warmer ambient temperatures. So-called 'mechanics' have been binning thermos for years but I doubt you will find a VW directive that authorized them to do it.

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 13 Dec 2006, 7:41 pm

#557455

i did end up finding a bit of info on the new style ones
but theres not much of it and i havent heard to many positive reports on them

-Joel

[ Edited on 13-12-2006 by DUB74L ]

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68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 · 18 Dec 2006, 4:37 pm

#558725

DUB74L wrote:i did end up finding a bit of info on the new style ones
but theres not much of it and i havent heard to many positive reports on them

-Joel

[ Edited on 13-12-2006 by DUB74L ]

I have heard from VW owners in Canada and top of the USA who have fitted these new type thermostats because the white stuff that forms from the moisture and because the oil doesn't get hot enough... is a problem..

I don't know if it ever gets that cold in Australia....
It gets to below zero here, but I don't usually go driving at that time of the morning.... lol...:P
I'll see what happens in the winter....

Just remember that millions of beetles in Australia and the USA & Canada all had their thermostats thrown away....
and it hasn't had any bad effects on the engines....

After all these years, the main thing if you still have the flaps and bar connected is to check on the spring, and maybe add another spring....
as if the original spring snaps, the flaps can close...
and then the engine will overheat...

old car rally rules, two carby springs, two bonnet locks or straps.... so:
Two springs are better than one..... lol...

and with our moderate to hot temperatures....
maybe a thermostat is NOT Needed....
unless you take your beetle skiing with you..... :P:o

Lee

http://community.webshots.com/user/vw68autobug

- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

PJMS Learner Dubber

8 posts · joined Jul 2006 · 18 Dec 2006, 9:14 pm

#558823

68AutoBug wrote:.....millions of beetles in Australia and the USA & Canada all had their thermostats thrown away....
and it hasn't had any bad effects on the engines....

How can you be sure about that? There are so many problems with aircooled engines these days, and peoples expectations are lower. Without an organised dealer maintenance record, there can be no way of knowing the true effects of widespread removal of thermostats.

Also, you don't need near freezing conditions for the thermostat to function. Even if you live in a predominantly hot area, VW would have no way of knowing if you would drive to a cooler zone, for a day. a month, or permanently (as you say, it can get to freezing in NSW). If the thermostat works, then if will function correctly for any weather condition. In circumstances where replacements are unavailable, then there is no choice but to run without, but I don't believe they should be arbitrarily discarded just because it is presumed they have little use.

[ Edited on 18-12-2006 by PJMS ]

Baja Wes V6 Baja Pioneer

3,119 posts · joined Aug 2002 · 19 Dec 2006, 9:42 am

#558910

What this thread needs is some facts.

Here is a graph showing the heat-up curves for a VW engine with and without the thermostats. I'm not sure what ambient temp it is.

The critical time is the time required to heat the cylinder above 70 degrees. This is because the most wear occurs below this temperature. Below 45 degrees is very bad because you get combustion by products condensing on the cylinder walls (like sulphur trioxide).

You can see there is almost no difference in time required to heat the cylinder above 70 deg C, therefore I'd say the thermstats don't do much for normal warm-up.

This next graph is a VW driving along a hilly test circuit with an outside air temperature of a very cold -5 deg C!!!

You can see the thermostat has a lag to respond. So with the thermostats it makes the engine run hotter. But, on the long down hill runs it also stops the engine getting too cold. The engine without the thermostats actually ran for 6kms with the cylinder temp below 60 degrees (causing excessive wear). But remember, the outside air temp was -5 deg C.

So if you are in QLD I would say you'd be better off without them (because you don't want the lag and high temp spikes). In you live in Tasmania then you probably don't want your cylinder temp getting too cold, so perhaps you should run them.

So there is no clear answer 🙂

Info shamelessly copied from Air-cooled Automotive Engines by Julius Mackerle (former chief designer of Tatro motor works).

Wes - www.offroadvw.net - 200HP Quad Cam V6 in a VW Baja - with climate control... 🙂
www.taylorcycles.com.au - My DH MTB racing brothers shop.

PJMS Learner Dubber

8 posts · joined Jul 2006 · 20 Dec 2006, 1:06 pm

#559194

I don't really want to sound argumentative, as the Julius Mackerle stuff is really interesting. However, the book was first published in 1961 and then updated in 1972. Would his tests be on the old thermo system of the later one? I think there would be some difference.

I do remember reading in one of the official VW maintenance manuals that the thermo system was effective even in hot or warm climate conditions, though it is obvious that as the ambient air temperature increases so the 'effectiveness' decreases. It may also be a case of some obscure VW thought processes, which they were very good at implimenting but very bad at explaining.