Bigdar 62 Report post Posted August 21, 2011 The wife's got a 3 series touring ( 318I ) which has been losing water, the only place I can find any signs is the thermostat housing, a kind of rusty residue around the bottom. So I fitted a new thermo yesterday... still losing water though . Around the seal of the old one there is evidence of a kind of mastic seal, but it shouldn't need that should it I cleaned the mating surface with emery before fitting aswell. Any help would be....well.... helpful : Quote Share this post Link to post Share on other sites
Symon 1 Report post Posted August 21, 2011 Did it not have a paper type gasket? I am not familiar with this engine though I must admit. It might be worth asking on bmwland.com Quote Share this post Link to post Share on other sites
Bigdar 62 Report post Posted August 21, 2011 It's got the rubber o ring that comes with it. But, speaking to a mate of mine it could be the fact that after changing the thermo I didn't run the engine up with the heater on full (schoolboy error :tut ) so the heater matrix is probably still filling, thus making the coolant level drop as it fills. So I could be in luck if that's the case Quote Share this post Link to post Share on other sites
jhc 28 Report post Posted August 22, 2011 what age is the car? Bleeding bmw engines after coolant loss is very important, and a royal pain in the backside too. It could be the water just filtering through, but if it is that means there is air in there somewhere which needs to be got out before it causes issues. Quote Share this post Link to post Share on other sites
Bigdar 62 Report post Posted August 22, 2011 It's a 2000 x reg. Got any ideas how to make sure all the airs gone? I've had the cap off and the heaters on full etc. but if there are any tricks I'd be grateful Quote Share this post Link to post Share on other sites
jhc 28 Report post Posted August 22, 2011 It should have a bleed valve, normally on the expansion tank/radiator. I'm not that familiar with the newer 4 pots but most of them have it there. Its a little plastic screw thingy. Park it with the nose slightly high, not too much though, run it up to temp with the fans/heaters on full and open the valve slightly right from the start until it only leaks water, no bubbles. Constantly top up the fluid while you do it. Then do it again. And again. And again. If you havent scalded yourself at least once, you havent done it right Sometimes it helps to pressurise the system while you do it, by blowing into the expansion bottle... but the valve is next to it, so you will need to be careful about boiling water squirting out into your face. Bleeding bmw's is a complete pig and can be very costly if not done right. Quote Share this post Link to post Share on other sites
jhc 28 Report post Posted August 22, 2011 http://www.impee.co.uk/radiator_flush.htm Skip to step 15 And in case you dont see it in his guide... Be very careful with the bleed valve, they break/strip the thread very easily... what with being a tiny flimsy plastic screw thats spent its whole life heating and cooling... god bless bmw engineering Make sure you let it cool completely before the final topup too. Quote Share this post Link to post Share on other sites
Symon 1 Report post Posted August 22, 2011 The 6 cylinder engines are even more difficult to bleed aparrently. I need to change the coolant on mine, and I am not looking forward to it.. Quote Share this post Link to post Share on other sites
jhc 28 Report post Posted August 22, 2011 They are a complete nightmare. I had to do mine a couple of times and it drove me batty. The principle is the same, just takes longer. You may find you have the old type of bleed screw too, where you actually have to take it all the way out for it to work (it has no 'channel' in it to let out the water)... which makes it fun putting it back in while there is boiling water spraying out the hole! If you do have one of them, go buy a newer one from bmw, they're only a quid or two and make it soooo much easier. I'm very much a home diy'er when it comes to car maintenance, but after many years of bleeding bmw's, a coolant change is something I would seriously consider leaving to a pro next time. Just to avoid the hassle. Quote Share this post Link to post Share on other sites
Bigdar 62 Report post Posted August 22, 2011 For fucks sake ! Do you think I should get her to fix her own car Hopefully I'm on the tail end of it now, I had already done the bleed screw thingy next to the filler cap, I should just have to do the top up:thumbs: I have had trouble with an old 5 series we had in the past which resulted in a fucked head gasket Why do things have to be so awkward :confused Quote Share this post Link to post Share on other sites
jhc 28 Report post Posted August 22, 2011 so you take it to a bmw dealer to have the work done Its not really that bad tbh, sometimes you do it first time and in 5 minutes its sorted... other times no matter how much you do it, it never bleeds right and you end up with blown gaskets/pipes and one hell of a headache Quote Share this post Link to post Share on other sites
