240 overheating with ice-cold radiator

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

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.

-- Tony