Throttle coolant bypass

[nomad]

So I bypassed the throttle coolant system to get rid of the hoses under the intake. I took a 5/8" heater hose and looped it from the water pipe to the block outlet. I think I'm going to buy a few hard coolant elbow fittings as I don't like the way the heater hose bends and wants to kink.

Any suggestions on where to find these?

I also have a stumble at idle and was wondering if I should put the unconnected throttle plate back between the throttle and the intake manifold. This would have a minimal effect but I'm wondering if it is part of my problem. The engine seems like it has a cylinder missing and then when I get it up over 1500rpm it acts totally normal.

Should I put this plate back? What have others done?

How tight should I torque the manifold to eliminate leaks?

[bmwman91]

I have heard of a lot of people removing the de-icer system without any noticeable effects.  Did it not stumble prior to this?  Maybe you forgot to reconnect one of the smaller vacuum lines?

As far as hose...you might be able to hit up the local parts store for the right inside diameter ribber hose.  I would imagine that high pressure fuel line would be more than adequate for your coolant bypass.

[tjts1]

Did you change any of the hoses to and from the idle control valve? I had an issue after this modification where the hose I was using between the idle valve and the manifold wasn't rigid enough and it would pinch itself off under a strong vacuum. This would cause the engine to stumble and some times die at idle. I don't think the stumble has anything to do with the heater plate so long as you don't have any vacuum leaks.

I used a little bit of RTV on both sides of the gaskets on the manifolds and TB to prevent any leaks.

[nomad]

The problem with the coolant bypass hose is that one end is 5/8, the other is 3/8 or something to that effect.

No stumbling at all prior to changing these and fixing a coolant leak.

I bought a brand new intake mani gasket that connects to the head but left the middle gasket stock. I may have to add RTV to stop this issue. Aren't these gaskets somewhat reuseable?

The only other vacuum line I see that was not affected by he bypass is the very small one going under the throttle body. It's black with red stripe and is old but looked ok to use. I'll replace it but I don't think that's it.

[e30s4evr]

I ran in to the same problem and decided to use the factory hoses that connected to either end. Then I just used the 'U' shaped aluminum tube to connect the two together.

http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=11_1272&hg=11&fg=35

So, reuse #18 and #26, shorten #11 and connect both 18 & 11 to 26 and your all set.