E38 V12 Cooling system overhaul

[tjpike]

Hi all,

I'm planning to do a cooling system overhaul and have some questions regarding the replacement of some of the coolant pipes, 2 in particular:

https://www.fcpeuro.com/products/bmw...il-11531711885

and

https://www.fcpeuro.com/products/bmw...se-11531440104

Does anyone have any pointers or tips for removal and reinstallation of these two pipes?

From what I understand, the first one just slides out, but what about the second one? it kinda just disappears behind the secondary air pump lines in front of the engine.

[tjpike]

anyone?

[CPHES]

They look odd. Can you look in realoem.com. I’ve been in the V12, and they don’t look familiar

[tjpike]

They look odd. Can you look in realoem.com. I’ve been in the V12, and they don’t look familiar

http://www.realoem.com/bmw/enUS/show...diagId=11_2301

It's part #11 and part #7

[CPHES]

So, part # 7 goes from the bottom of the water pump to the auto trans cooler. The diagram is missing an O ring at the pump. Do you have the puller for the harmonic balancer - if you are doing the pump?

[CPHES]

Are you pretty good as a mechanic? The m73 is not impossible to work on, but good solid skills are important. Take your time. The hose should be self explanatory as you take it apart

[tjpike]

Are you pretty good as a mechanic? The m73 is not impossible to work on, but good solid skills are important. Take your time. The hose should be self explanatory as you take it apart

Thanks for the tips, I'm not doing the pump, just all the old hoses. is it possible to replace the hose going to the pump without taking the pump out?

[CPHES]

Yes, if the pump is good, all hoses can be replaced without unbolting it. Also look at the elbow joint at the back left of the engine, near the brake booster. Not sure of your mileage, but many m73 pumps seem to start leaking around 120k. If you are in that range with an original pump, you should consider it.

[tjpike]

Awesome, thats what I intend to do. My car currently has 93k miles, and no leaks in that area, so should be good.

[RIboater2]

that second one is the tricky one. That Y fitting is plastic and will fail at some point. Mine did. That one screw under the intake is pretty impossible to get at without removing the intake. What I did, with the skill of a surgeon lol, was to remove that Y fitting in place and replace it with brass T. The hoses themselves were fine.
-RIboater"2" because i'm locked out of my account for trying to change my email. I don't advise anyone try it. Never got email validatoin to my outlook.com account and have emailed mod a few times to let me back in.

[asianvenom]

That second y-pipe is impossible to replace without removing the intake manifold, as it bolts into the top of the valley pan with a Allen hex screw. I m replacing my valley pan with a prefacelift valley pan which don't have that y connector.

Sent from my VS995 using Tapatalk

[CPHES]

This from e38.org - linked to bimmerboard is really good info
http://www.bimmerboard.com/members/d...akeremoval.pdf

[chrisn7]

So, part # 7 goes from the bottom of the water pump to the auto trans cooler. The diagram is missing an O ring at the pump. Do you have the puller for the harmonic balancer - if you are doing the pump?

The harmonic balancer does not need a puller - once the crankshaft bolt is removed, it just lifts away.

There is one hose you should look at, No 16 in that diagram, that passes from the bottom of the water pump to the header tank, passing behind the belt. The belt runs so close to the hose, that the hose is supplied moulded with a flattened section to achieve some clearance. Problem is, it balloons a little with age, so look very carefully to see if the belt is rubbing on it. At the pump end, an oerlikon clip is used, as there is no room for a worm drive type i.e an original style crimp type clip is required

[tjpike]

The harmonic balancer does not need a puller - once the crankshaft bolt is removed, it just lifts away.

There is one hose you should look at, No 16 in that diagram, that passes from the bottom of the water pump to the header tank, passing behind the belt. The belt runs so close to the hose, that the hose is supplied moulded with a flattened section to achieve some clearance. Problem is, it balloons a little with age, so look very carefully to see if the belt is rubbing on it. At the pump end, an oerlikon clip is used, as there is no room for a worm drive type i.e an original style crimp type clip is required

Hey Chris, appreciate the advice, but my question is why does realoem mention that I need a worm style?

[RIboater2]

you jinxed me. I've been trying to track down a slow leak and it is the small C shaped hose on #11. I replaced just that small C piece of hose. it's the one piece I didn't replace when I repaired mine last time because It's actually a firm piece of plastic as to be able to make that bend without kinking, but i was able to cut a piece of rubber hose to just the right length that it wouldn't bend in half. It has to tuck behind that emissions or air hose thing. I thought about coming up in front of it but it's very close to the fan. could probably clear it if I had to.

[chrisn7]

Hey Chris, appreciate the advice, but my question is why does realoem mention that I need a worm style?

Try a worm drive and see! There isn't even room for the 'threads' on a worm drive - the clamp needs to be a smooth band to fit.

Sorry, I did get the clip name wrong - its 'OETIKER':

http://www.oetiker.com/en/Products/C...ngs/Ear-Clamps

[CPHES]

Ok - the harmonic balancer does not need a puller, but it does need to be removed to change the pump. You need the correct tool to do that.

[chrisn7]

Indeed it does. The crankshaft locking tool is getting hard to come by now - I managed to borrow one from my dealer as they don't get to use it much now. I made a drawing of it though just in case...

[xboss]

An impact will pull the Jesus bolt with the red out. You can even torque it then mark lines on the socket for tty with an impact, all bypassing the need for the lock tool

[CPHES]

I have that tool - bought from the dealer - edited - you really need the tool to get it torqued correctly on installation.

[RIboater2]

I've mentioned it before but I locked my flywheel with vice grips and a block of wood to protect the bell housing. My jesus bolt came off with a ratchet wrench.

[xboss]

I have that tool - bought from the dealer - edited - you really need the tool to get it torqued correctly on installation.

Yeah, I have done it both ways. The comment is for other people in the future when they cannot find that incredibly hard to find tool or they do not have the time.

My system is fully rebuilt down to recounting the head manifolds after two trips in! The rear hose that mounts to the water manifold was melted under the clamp, looked great but was ready to pop. I would definitely replace it.

[chrisn7]

I've mentioned it before but I locked my flywheel with vice grips and a block of wood to protect the bell housing. My jesus bolt came off with a ratchet wrench.

Then the bolt must have been 'loose' - mine needed a metre long breaker and was bending a fair bit even with that. But then we have it easy compared to the V8's