Newbie post . Have had my XC 70 for three years . no major problems but some running repairs to be expected . Recently start of overheating problem . coolant checked on regular basis . Occasionally unexplained water loss and warning sign comes on . Water level topped up and car proceeds without difficulty . Last week however having not used the car for a week ,( but having checked the water the previous week ) after a six mile drive in very heavy traffic , much stop/start warning sign came and STOP ENGINE sign . Luckily was at destination when this happened . Parked , noticed trail of water behind and on opening bonnet smell of burning ,steam and hot water obvious . No sign of the fan operating . Car currently with the mechanic who indicates he thinks the problem is with the Bosch control module which is attached and forms part of the radiator fan assembly . Initial thought that this have might be a blown cylinder gasket but tested and that very luckily appears to be ok . Initial reaction to the fan diagnosis was that it might be possible to replace the control module alone but internet search tends to suggest the whole fan unit needs to be replaced . Can anyone please advise a model number/s for a suitable replacement fan assembly . Is there interchangability between v70 and xc 70 [ petrol and diesel ] and if so between what years would the unit fitted have been made ? Is there interchangability between the V70/XC70 and any other Volvo models ? The reason I ask is a dismantler I know has sent me photographs of a replacement fan unit from a V50 petrol 2008 which looks virtually identical but I supect will not work . The mechanic has not taken the existing unit out until we have got a replacement so I cannot quote a part number . Can anyone assist on this topic ? The water loss is still a mystery because a pressure test discloses nothing adrift and the alternative of water disappearing into the oil with the gasket fractured does not seem to apply !

 

Volvo Part # 30680547
The V50 does not use the same fan. according to Volvo's website. (It uses part # 31261988.)

https://usparts.volvocars.com/p/Volv.../30680547.html