240 overheating with ice-cold radiator

My 240 Diesel (1986) started to overheat, it takes approx. 15 minutes
to reach the red zone (it's winter now and below freezing outside).
When I stop the engine and check, the motor is hot, the radiator is
completely cold everywhere.
I replaced the thermostat yesterday, it did not help anything.
The system is filled with a blend of antifreeze and dist.water.
There's no loss of water, the sytem did not seeem to leak anywhere. The
hoses are in good condition, but the radiator (all metal modell) is as
old as the car. It does not leak but the little copper lamells are
falling out almost everywhere.
Is it possible that the radiator is completely blocked,so that the
water is not circulating at all, or do you think that there's something
else wich could cause the problem?

It's the second time that I drain the whole thing completely in a week
so I got a bit of routine with this part so changing the radiator would
not be such a technical problem, but I would prefer to be sure that
this is the problem before spend all my savings on buying a new
radiator.
It would be a great help if someone had an idea about it.

Thanks
Andrea

 

Is there a pump that circulates the fluid around? Sounds like you have
a dead water pump

 

I doubt the radiator would go from flowing to completely blocked
'overnight'. The most obvious candidate is the impeller has fallen off the
water pump.

Tim..

 

If the heater works poorly you probably have no circulation, if it does
work well you might have a blockage somewhere. Drain the coolant system
and stick a gardenhose in the various hoses and see what happens. I once
found a freezeplug which would jam the thermostat shut. On cooling down
the thermostat shut completely causing the freezeplug to drop down again
in the cylinderhead!

 

Thanks for the water-pump advice, I was kind of hoping it wouldn't be
that, since I do not have a good description how to change it (I foud
one description but for gasoline engines and I expect it's not the same
on the diesel).
I was searching the internet high and low for a Haynes manual wich
would talk about the Volvo 240 DL with Volkswagen engine but it does
not seem to exist or I did not search well.
My second thought is to try to find a Haynes for Volkswagen and apply
it with the Volvo but I have no clue wich Volkswagen would have the
same motor than my Volvo so I'm kind of stuck.
The heating works perfect we have a sauna on wheels if I put it on
MAX.
The radiator did show some signs of overheating in the summer
(trafic-jam on the highway for 4 hours) or if I drive above 100 km/h..

In any case I have to take out the radiateur even if I want to get to
the waterpump, isn't it? (so I might start for hunting for the blockage
with the radiator?)
Wouldn't it make some kind of noise if the waterpump is out of work?
Would it harm the car if I drain the system take out the radiateur and
it is staying on the street (around zero or bit bellow freezing)
without antifreeze meanwhile I'm hunting for blockage and charging
around for parts?

Perhaps I'm overworried about my car but I'm the second owner of it,
the previous one had it for 20 years and kept it in avery nice general
condition so I try not to ruin it.

Andrea

 

A suction side radiator hose getting soft and sucking flat could cause your
problem or a thermostat froze in the closed position. I have seen water
pump impellers either corrode away or fall off.
Dale P...........

 

Look in the engine bay for a plate with the engine type on it, the
manual might point u in the right direction. Using this code you can
probably find the right engine type. EG my volvo has B23E engine type,
this is stamped on the passenger side suspention mount

 

Not at all. The waterpump is used to tension the timing belt which has
to be removed, so getting at it is a large job. The engine is the same
as used in the VW LT van. Still think you have a blockage somewhere

 

Also possible is a blocked breather, so when you fill up the cooling
system the radiator doesn't fill up. Just had this on a 940 Turbo.

You can check the radiator for blockages, just remove the hoses and blow
through it, blocking any breather/filler hoses.