M30 Coolant Hose Replacement Question

[Kalevera]

To all my M30 knowledgable friends:

I've got a minute leak at the expansion tank/hose junction. This is the hose that goes from the exp tank to the heater core as well as to the Tstat (by traveling underneath the intake). I'm pretty sure the hose has gone south: there's a small puddle of coolant on the engine block under the starter (directly below this hose), and there are various wet spots on the hose, not even near the tank. I haven't ruled out the exp tank as also being faulty, but it's clear that the hose is very much done.

Question is: do I have to remove the head/intake in order to replace this hose, or can I just snake it through there over to the Tstat housing?

My aux water pump is also cracked somewhere and leaks a little coolant...so I guess I'll be doing the whole shebang: flush, water pump, tstat, most of the coolant hoses, and the aux water pump.

Best, Whit

[TheDuke]

I had the same problem with my M30. There is a small clamp (next to the reserviour) arond the hose, try tightenig it, worked for me.

By the way hi to all members.

[Kalevera]

I'm afraid to tighten it -- don't want to break the expansion tank fitting as it's made of plastic (ugh) and the cold makes things brittle

Plus, the car sat for two years prior to me buying it, so it's due for new hoses and a coolant flush...and probably a thermostat and water pump...and brakes...and paint (the list goes on...hehe).

Welcome to the club

Whit

[Rigmaster]

If you are careful to not put any stress on the expansion tank fitting, you should not be able to crack it- there is (or should be) a metal sleeve inside the plastic fitting.

Bret.

[shogun]

It is sometimes clogged and that is one of the causes of overheating. There should be a return flow into the expansion tank from the radiator.
See especially pic 3 in the link

click here

[Kalevera]

shogun - I just replaced that line after it snapped in the cold (read my "e34 hell" post from last week).

It's *not* a fun thing to replace, let me tell you. I had to contort it every which way because the wiring harness on my car is basically glued in place and hard to get around.

Because I loosened and lifted up on the heater valve when replacing that line, I've now got these other leaks. The aux water pump failing plastics is routine, from my understanding of it. But the other line is just worn out, I think. Will do a little exploration tomorrow before I call Patrick at BMA.

Best, Whit

[632 Regal]

try to tighten the hose after the engine is hot and the hose id more pliable, should be able to get a partial turn outta the deal.

[Hector]

the inside of the hose or the expansion tank spout with a little hylomar. This works pretty well, and I wish I could take credit for it but this is something that Bill R. has suggested in the past. The problem with this hose is that, by design, it is somewhat short in reaching the expansion tank. Working at it a bit is when you can get the friggin hose to slide over the spout, and when you do, the hose doesn't look like it's mating to the spout snugly/correctly. This definitely subtracts from the life of the expansion tank. Just before I replaced mine, the plastic collar holding the steel spout had cracked. I'm thinking about expanding the hose a bit to relieve stress and to prolong expansion tank life.

To all my M30 knowledgable friends:

I've got a minute leak at the expansion tank/hose junction. This is the hose that goes from the exp tank to the heater core as well as to the Tstat (by traveling underneath the intake). I'm pretty sure the hose has gone south: there's a small puddle of coolant on the engine block under the starter (directly below this hose), and there are various wet spots on the hose, not even near the tank. I haven't ruled out the exp tank as also being faulty, but it's clear that the hose is very much done.

Question is: do I have to remove the head/intake in order to replace this hose, or can I just snake it through there over to the Tstat housing?

My aux water pump is also cracked somewhere and leaks a little coolant...so I guess I'll be doing the whole shebang: flush, water pump, tstat, most of the coolant hoses, and the aux water pump.

Best, Whit

[Kalevera]

I tried tightening it up, but it still leaks...so I'm going to replace the hose after I take it all apart and see what else is busted...

best, whit

[Javier]

the intake without removing it, but be careful, there is a couple plastic clamps holding the hoses in place, I broke one of them as it is hard to figure out they are there when pulling the hose. Clamps are part number 11 in this link:

http://www.realoem.com/bmw/showparts...87&hg=11&fg=35

May be you are luckier than me, and release the clamps before pulling the hose.

Javier