cu engine cooling flaps

[988mick]

ive stripped off my tinwear to clean and paint the engine and notice that my thermostat is fully expanded when cold,so its obviously knackered and has not been opening the cooling flaps to let the air flow trough the oil cooler.is there any good reason why i couldnt bin the cooling flaps altogether,tape up the joints and just let the air flow all the time.
thanks.
mick.

[Plasticman]

the default position with regard to the stat is = flaps fully open, so if yours are shut then something is not connected correctly or stuck
mm

[Hacksawbob]

The engine will take longer to get to running temperature so increased wear, particularly in winter. Reduced efficiency as well probably.

[Plasticman]

dont get cold in Dublin though
mm

[bigherb]

so its obviously knackered and has not been opening the cooling flaps to let the air flow trough the oil cooler.is there any good reason why i couldnt bin the cooling flaps altogether,tape up the joints and just let the air flow all the time.
thanks.
mick.

Take another look at them and how they work you'll see they are deflectors to direct air through the oil cooler. No flaps then no air through the oil cooler.

[988mick]

There was no adjustment problems,the problem is the thermostat is fully expanded and rather than replace it I taught I might just bin the set up.i think sarran done the same thing in one of his videos on the cu engine.i think I will see if I've a working stat on one of my other engines and just keep the flap set up as Vw designed it.i soppose they didn't put it in there for the crack.

[aruntaylor]

I've binned the stat and the flap. The flap is there for helping the engine to warm up it's closed until warm then it's open. To be honest it doesn't get driven in the winter anyway so I can't say if the warm up takes longer.

[988mick]

Yea that's exactly what I taught,they stay closed till the engine gets up to temp and the stat expands and opens the flaps to let the air flow.so I'm concluding that cause my stat is broke that the engine was running hotter.

[oorwullie]

bin the thermostat and leave the flaps.
i find it difficult to believe that sarran john suggests binning the flaps as well, they are there for a reason.............

[bigherb]

bin the thermostat and leave the flaps.
i find it difficult to believe that sarran john suggests binning the flaps as well, they are there for a reason.............

A very important reason.

Cold engine the flaps closed not a great deal of air passes by and also directs the airflow away from the oil cooler to aid warm up. Note the shape of the flap and the gap at the bottom.


The oil cooler is situated hear and needs the airflow to go downward, but as we know from school air travels in a straight line unless deflected so not much is going to go through the oil cooler when it is needed.


So VW designed the flap to direct air through the oil cooler when the flaps are open.
The flap covers the oil cooler but the bottom edge of the flap is now open so a proportion of the air from the fan is forced through the oil cooler.


So no flaps screwed engine.

[988mick]

Very good explanation big herb thanks.ill see if I have a working stat in the shed and if not I'll refit the flaps and lock them in the open position.

[oorwullie]

Very good explanation big herb thanks.ill see if I have a working stat in the shed and if not I'll refit the flaps and lock them in the open position.

you don't need to lock them at all, provided the springs are in there the flaps stay open.

when the thermostat is fitted it heats up and opens out then the cable tension is released.
no thermostat fitted the flaps stay open.

[sarran1955]

Hello,

Very good explanation big herb thanks.ill see if I have a working stat in the shed and if not I'll refit the flaps and lock them in the open position.

AAAAAAAAAARRRRRRRRGH..

Wongy flaps syndrome..

No.. seriously.. fit the shutters in the open position by all means..

What is important is that the engine is timed right...clean and shiny..

and that all the tinware is airtight....

I would not rely on the thermostat..

Cordialement,

[988mick]

yea john thats the plan.a good clean and repaint the tins and service and tune up.i just have no faith in the thermostats so would rather not be relying on it.
thanks.
mick.