Sealing the Right Angle Coolant Connector

[Alistair Francis]

I recently changed all of the plastic/rubber tubes/connectors for the cooling system and it appears that I have a leak. I manually pressurised the system today and it's unable to hold at 1bar for long. I managed to find 3 different connectors that must have been loose and tightened them pretty easily. Now it looks like part 1 from this diagram is leaking (https://www.realoem.com/bmw/enUS/showparts?id=CH73-USA-05-1996-Z3-BMW-Z3_19&diagId=11_1558). I remember it being a pain to insert in the first place. Does anyone have any good ways to seal it without having to remove the entire intake manifold again?

PS: In all my filling/bleeding I somehow managed to snap the bleeding screw in the radiator (https://www.realoem.com/bmw/enUS/pa...3_19&mg=17&sg=05&diagId=17_0089&q=17111712788). I was able to get it out, but it seems strange that it broke and I'm a little worried I have damaged the seal. Has anyone seen that break before?

 

[Synclare]

There can be a fair amount of corrosion around the aperture in the block. You need to take time to scrape the recess the 'O' ring sits in, if not the plastic connector pipe doesn't push fully home. If the block is severely corroded/pitted around this aperture then I guess one bodge could be to use a silicon sealer once all corrosion is removed. I hate these plastic coolant pipes. The other one that causes similar problems (4 cyl) is the plastic pipe exiting the very back of the cylinder head. Alloy corrosion around that aperture also causes leaks/poor fitment, again you have to meticulously clean the metalwork to remove the powdery deposits. 50% coolant mix helps reduce corrosion, particularly in mixed metals - all to do with the reactivity series of different materials.

 

[Cooper]

The coolant drain plug in the radiator almost always breaks so it is wise to have a spare on hand whenever you do this type of job. If it doen't break go and buy a lottery ticket because you are sure to win!

 

[Alistair Francis]

There can be a fair amount of corrosion around the aperture in the block. You need to take time to scrape the recess the 'O' ring sits in, if not the plastic connector pipe doesn't push fully home. If the block is severely corroded/pitted around this aperture then I guess one bodge could be to use a silicon sealer once all corrosion is removed. I hate these plastic coolant pipes. The other one that causes similar problems (4 cyl) is the plastic pipe exiting the very back of the cylinder head. Alloy corrosion around that aperture also causes leaks/poor fitment, again you have to meticulously clean the metalwork to remove the powdery deposits. 50% coolant mix helps reduce corrosion, particularly in mixed metals - all to do with the reactivity series of different materials.

I don't remember it being too corroded when I took it out, but it's starting to sound like I have to do the job again to double check. Luckily I don't think the one at the back of the engine is leaking, as I don't see any moisture back there. I'm just dreading taking the bottom intake manifold off again as that is a real pain.

 

[Alistair Francis]

The coolant drain plug in the radiator almost always breaks so it is wise to have a spare on hand whenever you do this type of job. If it doen't break go and buy a lottery ticket because you are sure to win!

This wasn't the drain pulg though, it was the bleeder plug at the top of the radiator. I hope it also has the same issue

 

[Alistair Francis]

Thanks for the info. After some more digging it looks like the radiator bleed screw does break and that isn't unusual.

I'm thinking for the leak that I might try to gently push in the plastic pipe using a long spanner extension extender. I can't bring myself to take apart the whole thing again. I'm hoping maybe just a gentle push will firmly lock in the piece. It doesn't leak very much, so I'm guessing it's just a small gap in there.

If that doesn't work then I will have to take apart the manifold and really clean out the metal. Does anyone know if I will I need to drain all of the coolant from both drain plugs to take that plastic part out?