M42 Mess Under Intake: Coolant Leaking?

[Powling]

I'm in the middle of doing the mess under the intake mod, and have hit a bit of a snag when taking off the old coolant hose highlighted in the pic below...



The problem I am having is when I remove the old hose from this fitting, it starts spewing coolant everywhere. In none of the threads that I've read about this mod ever state that coolant is suppose to come out of this fitting when the old hose is removed, so I'm a bit puzzled.

What am I doing wrong?

[roguetoaster]

There is coolant flowing through that pipe, and when the level in the whole system is such that it can come out there without being under pressure it will. Also, when you pull a hose off of a fitting you often create suction, which will draw out a small amount of coolant.

Or are you saying that you are trying to run the system without a hose there?

Either way, clean up the spilled coolant and connect that fitting to the nipple on the cylinder head between cylinders 3/4.

[Powling]

There is coolant flowing through that pipe, and when the level in the whole system is such that it can come out there without being under pressure it will. Also, when you pull a hose off of a fitting you often create suction, which will draw out a small amount of coolant.

Or are you saying that you are trying to run the system without a hose there?

Either way, clean up the spilled coolant and connect that fitting to the nipple on the cylinder head between cylinders 3/4.

No, I'm trying to connect the new hose to both those nipples for the bypass as outlined in the mess mod threads that are out there.

I originally thought it was only a little bit of coolant that was coming out once I took the old hose off the nipple, but it streams out and after 15-20 seconds it doesn't seam to let up at all.

[gespinal0301]

No, I'm trying to connect the new hose to both those nipples for the bypass as outlined in the mess mod threads that are out there.

I originally thought it was only a little bit of coolant that was coming out once I took the old hose off the nipple, but it streams out and after 15-20 seconds it doesn't seam to let up at all.

Take the radiator cap off to relieve some pressure and double check that there's no more additional coolant in the system by opening up the drain plug

[Powling]

I decided to just switch the hoses quickly and deal with the mess but noticed that the 5/8in heater hose I picked up is REALLY oversized for the fittings. All the tutorials state that the bypass hose is 5/8in, but it doesn't seem correct to me. Thoughts anyone?

[iPee]

I used the E36 part to bypass the hose. I'll see if I can find a part Number later. It has the perfect amount of bend and fits both sides perfectly.


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[Powling]

I used the E36 part to bypass the hose. I'll see if I can find a part Number later. It has the perfect amount of bend and fits both sides perfectly.


Sent from my iPhone using Tapatalk

Thanks - I was actually able to make it work with the 5/8in hose. The nipple on the plastic tube side fits 5/8in perfectly, but the other nipple was smaller so I just cranked down the clamp on that end and it seems to fit well. Didn't show any leaks so far which is good.

On another note - I noticed the PO must have stripped the throttle body bolts / studs as one of them wont tighten down at all anymore. I might have to retap the intake manifold for a larger bolt or get a new intake manifold all together.

[iPee]

https://www.fcpeuro.com/products/bmw...mw-11511739245

In case anyone is wondering for future reference. I was going to clamp it down too but was worried I may break something.

[Powling]

https://www.fcpeuro.com/products/bmw...mw-11511739245

In case anyone is wondering for future reference. I was going to clamp it down too but was worried I may break something.

Good to have for future reference for sure.

Link doesn't work for me, but I can see the part number in the link you posted.

[TobyB]

You're going to want to make a bigger mess, I fear-
that plastic pipe should be replaced while you're in there.
It gets brittle, and the nipples break off, and the o- ring
slot at the block breaks off. You lose all your water in a hurry.
Then your motor melts in about 30 seconds on the freeway.
Because it never seems to happen anywhere else...

Also, get the right size hose- cranking the clamps will leak, eventually-
or sooner, if you end up crunching the plastic pipe with the clamps.

Jus' sayin', cause I've been there and fried that...

t

[AndrewBird]

That plastic nipple looks broken off. Maybe it's just the angle. Should look like this:


Heli-coil the throttle body threads. Do all 4 while you are at it. The cast aluminum is very soft and will commonly strip out. Adding heli-coils gives you steel threads and you won't have a problem again.

[Powling]

That plastic nipple looks broken off. Maybe it's just the angle. Should look like this:

Heli-coil the throttle body threads. Do all 4 while you are at it. The cast aluminum is very soft and will commonly strip out. Adding heli-coils gives you steel threads and you won't have a problem again.

Thanks for the heli coil advice, I totally forgot about them as an option haha.

As for the nipple pic, it isn't of mine exactly, I just took the pic from one of the DIY threads posted ages ago.