Help with blown radiator

[Gareth]

Yesterday whilst having mot done and with engine left running on ramp for some time with no air flowing past,the outlet pipe at top of radiator cracked off leaving about 10mm stub. Obviously not the best scenario whilst undergoing an mot but they managed to reconnect hose to stub and after refilling with water, did the emissions test ok and luckily she passed the mot and I gingerly drove about 10 miles home.
She is a 2000 3.0 with 125k and I have read that the plastic radiators do get brittle?
I have noticed a tendency to start to overheat if stuck in traffic but I don’t think the z3 cooling systems are that good in the first place and I can’t see any signs of head gasket failure.
My problem is what do I replace other than the radiator? Don’t want to spend too much but is it worth doing the water pump and thermostat whilst garage has her together presumably with top hoses?
Fan seems ok and as with all these things, where do you stop but would like to do the essentials.
Thanks for any guidance.
Gareth

 

[Ianmc]

My experience of BMW radiators (Z3, E36 etc) is that they last for around 20 years. Water pump/thermostat replacement would likely be worthwhile preventative maintenance if original. Hoses as needed on inspection.

 

[Gareth]

Thanks and at 22 years old, have gone past best before date! Will get it all priced up as not sure if within my abilities to do the work as now approaching 70 and with no workshop. I think the hoses will need replacement as the top one seems to have flattened but not sure how long has been like that and did notice her getting a bit hot if stuck in traffic recently. As a matter of interest, what is the big fan positioned in front of the radiator with a plastic grill in front of it? Is that an extra electric fan although have never seen it working and it won’t turn by hand?

 

[Rudyrov]

The front fan is for the air conditioner, when the AC pump is engaged, it's engaged.

 

[Gareth]

Thanks and wondered if it was that or an extra cooling fan although mine doesn’t seem to come on even when air con switched on and perhaps that’s why air con not that cold although air con was serviced and regassed in the spring? Another thing to sort out then!!

 

[Rudyrov]

Thanks and wondered if it was that or an extra cooling fan although mine doesn’t seem to come on even when air con switched on and perhaps that’s why air con not that cold although air con was serviced and regassed in the spring? Another thing to sort out then!!

Could be a bad fuse or a relay, check for power at the connector when the AC is on. Might be worth your time to fix or might be a can of worms, but might be nice to know whats up.

 

[SV8Predator]

Thanks and wondered if it was that or an extra cooling fan although mine doesn’t seem to come on even when air con switched on and perhaps that’s why air con not that cold although air con was serviced and regassed in the spring? Another thing to sort out then!!

As has been said, the front fan is for the A/C. It doesn't "automatically" come on as soon as the air-con is switched on though, it is there to regulate the pressure in the system. If the system pressure gets too high, a pressure-switch will switch on the fan, which blows through the front condenser radiator and lowers the pressure.

 

[Gareth]

Ah thanks for the update so will just keep an eye on it for the time being.
The radiator will take priority at the moment as scared to drive too far in case the top hose comes off the remaining half inch stub sticking out of the radiator although might be ok for short trips until engine gets hot?

 

[Jack Ratt]

I'd recommend changing the water pump and thermostat whilst the radiator is out. It will add less than an hour to the job. It's not a difficult job to do at home. Also, when you refill the system, raise the front of the car and put the heater controls to full temperature

 

[OOoOO]

As a matter of interest, what is the big fan positioned in front of the radiator with a plastic grill in front of it? Is that an extra electric fan although have never seen it working and it won’t turn by hand?

If it won't turn by hand it is either partially or fully siezed and the fuse will have blown. I had this recently on a friends car with the same MOT/top pipe situation. We freed off the fan with gentle persuasion, replaced the fuse and the aux fan now kicks in to maintain temperature whilst idling.

 

[t-tony]

If you can't turn the electric fan by hand it is seized, no doubt about it. A 3.0 is one of the least likely to have head gasket issues ( not impossible but unlikely) more likely to be water pump and thermostat problem.

Tony.

 

[Gareth]

Thanks and will add a new electric fan to the parts list! Can’t quite see how to get it out but presumably easier once the radiator is out? Will also check the fuse to it.

 

[t-tony]

If the fan (motor) is siezed its likely the fuse will be blown.

Tony.

 

[t-tony]

Thanks and will add a new electric fan to the parts list! Can’t quite see how to get it out but presumably easier once the radiator is out? Will also check the fuse to it.

Have a look on YouTube, there are lots of videos on there.

Tony.

 

[Gareth]

Sorted the front fan by cutting away some of the mesh shield and with a bit of persuasion and wd40, the fan now spins freely and runs when air con on. As you said, had to replace fuse 40 as that presumably blew when motor first seized up. Possibly if I had done this before the mot it would have saved the radiator although probably getting near its end point anyway.
will see where I can get the parts as might try doing it although does it come out from top or bottom as don’t have a ramp. Might have a look to see what info is online but all seem to be American?
Thanks for all the guidance so far as have made some progress!

 

[t-tony]

Rad comes out the top, but youneed to remove the cooling fan from the water pump, then the cowling.

Tony.

 

[Jack Ratt]

I got my spares from Euro Car Parts when I refreshed the cooling system on my 2.8 auto. That was radiator, water pump and thermostat, and I got the new hoses from Autodoc online from their Ebay shop

 

[Gareth]

Thanks and will have a look at those places