Leak under throttle body - what hose/ring is this?

[e30mitch]

Hi Everyone,

I noticed that my car started leaking coolant/water from underneath the throttle body. I THINK, I've located the source - and it seems to be the "o-shaped" ring that is drilled into the block (pics attached) . Can anyone help me identify what this part is called, so that I may order it? Or any other feedback is greatly appreciated.


Thanks!

[roguetoaster]

I doubt that it's a core/freeze plug as you seem to be indicating.

Most likely it's the plastic water pipe or a hose that comes off of the top of it. You'll want to get at least the plastic water pipe (a BMW one for reliability), and an o ring for the pipe. Perhaps consider finding some appropriate coolant hoses and doing the mess under the intake delete too. Either way, to get to the leak you'll want new intake manifold gaskets and a new throttle body gasket (or two if you want to keep the hoses under the manifold the same).

[mike.bmw]

The mess under your intake looks to be.... a mess. As roguetoaster said, it could be the pastic coolant pipe coming off the block. It could also be one of the other coolant lines in that area sprung a leak and is dripping/spraying on the block. Coolant runs through the throttle body plate as well as through those metal U-shaped line that is intertwined with the vacuum lines. Here are a few photos of the assembly in this post: https://www.r3vlimited.com/board/for...72#post6701372

[e30mitch]

The mess under your intake looks to be.... a mess. As roguetoaster said, it could be the pastic coolant pipe coming off the block. It could also be one of the other coolant lines in that area sprung a leak and is dripping/spraying on the block. Coolant runs through the throttle body plate as well as through those metal U-shaped line that is intertwined with the vacuum lines. Here are a few photos of the assembly in this post: https://www.r3vlimited.com/board/for...72#post6701372

Thank you! I'm a noob in this, and I'm sure you and roguetoaster are correct. If I recall correctly, my mechanic did say it seemed like it was a plastic pipe that was coming off the block - something about needing a new ring that goes into the block. Would you happen to know where I can order this? If this comes as a whole kit with the hoses and all, that would also work - I'll just put everything new. Thanks!

[mike.bmw]

Thank you! I'm a noob in this, and I'm sure you and roguetoaster are correct. If I recall correctly, my mechanic did say it seemed like it was a plastic pipe that was coming off the block - something about needing a new ring that goes into the block. Would you happen to know where I can order this? If this comes as a whole kit with the hoses and all, that would also work - I'll just put everything new. Thanks!

Here's what I usually do:
- go to realoem.com (https://www.realoem.com/bmw/enUS/par...-E30-BMW-318is)
- find the parts diagram(s) that include the parts you need
- copy/paste the part numbers into google
- try to find good pricing (I usually go with FCP Euro, ECS Tuning, or a few other vendors)

For the plastic coolant pipe you'll want genuine BMW as the aftermarket ones are prone to early failure. You'll need an o-ring as well: https://www.realoem.com/bmw/enUS/sho...60#11531714738

Some of the mess under the intake: https://www.realoem.com/bmw/enUS/sho...diagId=11_1272

When I replaced my "mess under the intake" I went with all new hoses, clamps, etc. There wasn't a kit available so I had to go through the diagrams and pull all the part numbers. I replaced the fuel lines, vacuum lines, most of the coolant lines. It wasn't a cheap parts bill. As roguetoaster suggested there are ways to bypass most of these hoses completely. It's a cheaper fix with many less failure points. If I go through this process again at some point I may delete/bypass the mess.