Additional thermostat? wtf? and which hose is which to heater core?

[FetusGoulash]

Ok searching here and e30tech brought me no answers.

2 questions:

1st and probably easiest is which hose goes where? I just replaced the heater core on my car (non a/c, so it has the FML remove the dash type heater core with valve on opposing ends) and now i dont know which hose to attach to the upper and lower tubes coming from the heater core. They had been looped since i bought the car so nothing to go by.

there is one hose that comes from the driver side of the engine, metal pipe runs along the block underneith the intake manifold then rubber to the heater core
and the second hose comes from the pass. side of the car and has an aluminum valve setup on it then continues to the heater core input/output.
Which is top and which is bottom??

also the above mentioned valve thingy is an additional thermostat according to realoem.com. what is its purpose if i also have the other thermostat near the radiator?? is this only for getting heat into the car before the larger thermostat has opened?? or???

#1 in the pic is the additional thermostat, it is along the firewall above the bellhousing:

[FetusGoulash]

Wow this M10 forum is sheeeeit
No one can tell me anything? i mean go look at your car and tell me what hose is on top and what is on bottom..

[Jean]

Can you take pics and post them? My 84 318i only had one thermostat near the radiator on the passenger side and only one heater core valve. I have heard of some early cars having two, but I would like to see pics .

[SoopaGhetto]

this is an e30 recall item. It is a coolant by pass valve that when in "over heating" conditions, it stops coolant from going into the heater core thus reducing the chance of coolant burn if the heater core was to explode.

this item is discontinued through bmw but you can find them on some vehicles. earlier models may not have them unless the owners took advantage of the free unit through bmw.

I put one in my car bc my core blew up a few times on me and i dont like getting burned...a good thing to have id say

[Dirtbleed]

I threw mine in the garbage.

[FetusGoulash]

Thanks guys. I think i may by-pass it as i seem to be getting random and odd water temp spikes. needle will hit 3/4 and no heat in the car. then minutes later returns to normal, so i wonder if that thing is sticking/clogged

[Nürburgring]

I tore into my '91 318is with an M42 this week to do the "mess under the intake" delete. I came across the "additional thermostat" which gave me some serious heartburn...I have deleted it...for now but I sure don't feel good about it as I don't want my heater core to explode and scald my lower half. Yikes. Anyone have a follow-up to this delete? See my video for further details.

https://www.youtube.com/watch?v=CXLAbQjiThA&feature=youtu.be

[packratbimmer]

I think that was a recall to keep your legs from getting scalded.

[Nürburgring]

I think that was a recall to keep your legs from getting scalded.

Correct. That's what I've learned also. I'm going to tempt fate and roll without it.