328i E36 expansion tank replacement

[B234R]

So I have a small leak in the expansion tank of my 328i, and I got a new expansion tank, level sensor, lower tank gasket and sensor gasket.
I have replaced expansion tanks in other cars, but BMW seems to like getting things complicated and I don´t know how it´s attached to the radiator. Is it possible to take out the tank without removing the whole radiator? I suppose I´ll have to empty all the coolant.
If it´s difficult I´ll take it to the workshop, as I remember that bleeding was a real pain, and I´m in a not very lucky phase as a DIYer lately.

Thanks!

[E30M3SE]

Does this help?

[B234R]

So the only thing that keeps the tank in place is the number 5 part?
Surely it will be neccesary to empty all the coolant.

[E-bmw]

Stick a bowl under that end of the 'rad and just do it, what will come out is what you needed to drain.

[morgrp]

B234R said:

So the only thing that keeps the tank in place is the number 5 part?
Surely it will be neccesary to empty all the coolant.

Looks like it with number 3 being a rubber seal to stop it rattling about - Might have stiffened over the years so (if you can get to it) might help to try and soak some silicone spray into it to help easy it out - I'd just siphon out the coolant from the bottle and as said bucket/bowl underneath to catch any residual - once the coolant drops lower than the bottle it will stop pissing out - just catch as much as you can, put it back in and top up with water

[iSore]

Tbh, you may as well replace the rad if it's starting to look a bit old and crusty. They're 30 mins start to finish. I have 2 or 3 really nice newish ones on a rack in my workshop.

[g3org3y]

iSore said:

Tbh, you may as well replace the rad if it's starting to look a bit old and crusty. They're 30 mins start to finish. I have 2 or 3 really nice newish ones on a rack in my workshop.

As someone who has gone through a couple of rads on my E36, inclined to agree. The rad comes with the expansion tank and you don't need to mess around with trying to separate them.

Of course, once the rad is out, you might as well do the waterpump/thermostat/hoses etc.

(NB, different rad with or without aircon btw so make sure you get the correct one).

[B234R]

I´ve seeing new radiators in the internet at really good prices, but the problem is that I need to use the car and I can´t afford to let it a few days while the radiator is deliveried. Mine is a bit newer than the car, it was made in 2002.

Well, I´m going to give it a try, thanks everyone!

[morgrp]

B234R said:

I´ve seeing new radiators in the internet at really good prices, but the problem is that I need to use the car and I can´t afford to let it a few days while the radiator is deliveried. Mine is a bit newer than the car, it was made in 2002.

Well, I´m going to give it a try, thanks everyone!

Technically its a simple job - often its more the puzzle of trying to fit it all together as they tend to be sandwiched among things

[Vince70]

I’ve done a few expansion tank changes on the E36 and to be honest if the expansion tank is bowed it’s time for a new rad as the radiator plastics can get a bit brittle with age and it can be a pain to get them to seal on the bottom seal

A new rad is only about £60 and takes half hour to fit, I really wouldn’t bother with an expansion tank just go for a radiator and if you shop about a Nissens rad can be had in that price range which are a good aftermarket make.

[B234R]

Vince70 said:

I’ve done a few expansion tank changes on the E36 and to be honest if the expansion tank is bowed it’s time for a new rad as the radiator plastics can get a bit brittle with age and it can be a pain to get them to seal on the bottom seal

A new rad is only about £60 and takes half hour to fit, I really wouldn’t bother with an expansion tank just go for a radiator and if you shop about a Nissens rad can be had in that price range which are a good aftermarket make.

How right you are! Removing the old bottle was difficult, but fitting the new one was a real pain. In fact, It didn´t fit properly, so as soon as I started to fill the tank, a leak appeared.
I understand that, after all these years, the plastic radiator housing where the tank fits warps slightly, just a little but enough to make the new bottle doesn´t insert 100%.

I´m going to take the car to the workshop, perhaps they can put it right, although I´m sure they´ll tell me the solution is a new radiator.

Thanks to everyone!