Coolant flowing off back of belly plate.

blktoptrvl · #1 03-01-2017, 12:54 PM

137K

I got home a little after I got the "Low Coolant Level" message. I watched and the temperature gauge never moved.

But there were steam vapors coming from somewhere. So, I let the car cool and then removed the overflow cap - the tank was empty. There was no sign of water on the floor.

So, I refilled at the overflow tank - it took about a gallon of water. I was starting to wonder where all this water could be going when I started hearing it hit the floor. Looking under, I could see that the water was flowing off the rear end of the aluminum stiffening belly plate.

I could also see a little wetness on the plastic plate under the radiator. So thinking it might be a cracked radiator, I pulled the fan so I could see better and started pouring water again - it does not seem to be the radiator.

Going to my Bentley paperweight I could find no coolant routing diagram.

So, my questions are: does anyone have a routing diagram that shows where all the hoses are?

Does anyone have experience with water pouring out the back of the engine when the overflow tank is filled?

Of course I am hoping there are hoses I am not seeing and it is not the valley pan, but I'd appreciate any suggestions.

Edit:

So far, this seems to be the best tread related to what I am experiencing...
https://xoutpost.com/bmw-sav-forums/...lant-leak.html

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williamx5 · #2 03-01-2017, 07:36 PM

Good day!

That thread is a good one to read for the M62TU motor, but you have the N62 and it has a different set of issues... I would say it is the valley pan if it was the M62, but I don't remember hearing issues about the N62's having issues... There is a tube that goes from the rear to the front under that cover, and something about the gasket failing. Poor design (MY two cents)...

I think it might be a good idea to pull the stiffening plate to better get an idea where the coolant is coming from... I would think it has to be a coolant hose if it is just pouring out when you fill the tank (without the motor running)... Might also be the water pump and a quick check of the front shaft on that would indicate it's condition...

About half way thru page 12 (post 116) I go into the hoses for our motors after my rebuild... Not sure it could help, but......

https://xoutpost.com/bmw-sav-forums/...roject-12.html

Let us know what you find out please!!

Cheers!!!

blktoptrvl · #3 03-01-2017, 07:46 PM

Quote:

Originally Posted by williamx5

Good day!

That thread is a good one to read for the M62TU motor, but you have the N62 and it has a different set of issues... I would say it is the valley pan if it was the M62, but I don't remember hearing issues about the N62's having issues... There is a tube that goes from the rear to the front under that cover, and something about the gasket failing. Poor design (MY two cents)...

I think it might be a good idea to pull the stiffening plate to better get an idea where the coolant is coming from... I would think it has to be a coolant hose if it is just pouring out when you fill the tank (without the motor running)... Might also be the water pump and a quick check of the front shaft on that would indicate it's condition...

About half way thru page 12 (post 116) I go into the hoses for our motors after my rebuild... Not sure it could help, but......

https://xoutpost.com/bmw-sav-forums/...roject-12.html

Let us know what you find out please!!

Cheers!!!

Thanks much for the reply.

With the fan removed, I can see that there is no leaking or weeping from the water pump. I am delaying the job - hoping someone else will chime in before I start taking things apart.

Before I do anything, I will try to get a mirror behind the block to see if I can see ANYTHING back there, second will be the plate.

Thanks again.

itsbrokeagain · #4 03-01-2017, 08:53 PM

Do the N62s have the same coolant crossover plate on the block like the M62s? If so I'd wager it may be leaking from there if you're seeing coolant at the back of the stiffening plate. Only downside is the trans has to come down to fix it.

crystalworks · #5 03-02-2017, 02:50 AM

Could also be the rear "kidney" coolant plate that goes behind the engine (trans has to come out to access). Part 5 below.

Here is a decent page from BMP about tracing coolant leaks in the N62:

BMP design : When to Check your BMW Cooling System

X53Jay4.8is · #6 03-02-2017, 04:34 AM

At the mileage you have its more than likely the seals on the coolant tubes of the N62 engine. Its a well known problem and just needs some maintenance attention. You should really plan to update all the coolant hoses and seals at the back of the engine for the age and miles of this vehicle. The hoses do get soft and deteriorate rather quickly. If you change/fix just where the leak is in a couple months you will be chasing another leak. Do yourself a favor and just run through changing all of the hoses and coolant seals.

blktoptrvl · #7 03-02-2017, 02:12 PM

Quote:

Originally Posted by crystalworks

Could also be the rear "kidney" coolant plate that goes behind the engine (trans has to come out to access). Part 5 below.

Here is a decent page from BMP about tracing coolant leaks in the N62:

BMP design : When to Check your BMW Cooling System

Quote:

Originally Posted by X53Jay4.8is

At the mileage you have its more than likely the seals on the coolant tubes of the N62 engine. Its a well known problem and just needs some maintenance attention. You should really plan to update all the coolant hoses and seals at the back of the engine for the age and miles of this vehicle. The hoses do get soft and deteriorate rather quickly. If you change/fix just where the leak is in a couple months you will be chasing another leak. Do yourself a favor and just run through changing all of the hoses and coolant seals.

Thanks for the input.

I have decided to wait on this job until my Boroscope arrives in the mail. It is a cheap unit ($13), but it plugs into my laptop.

I took a mirror and could see that there is indeed a hose connector that goes directly into the back of the block. But with the mirror I could see no further.

I do have a question about the bulkhead where the cabin filter is located - when removed, does this give full access to the top of the engine?

Boy, I really don't look forward to pulling a tranny - laying on my back on the floor. But - it's that or pay - any idea how much a indy would charge to replace that rear plate?

Or, maybe it would be easier to pull the engine/tranny together? Ugh.

blktoptrvl · #8 03-02-2017, 02:36 PM

The valley pan seems to have a nose on it... Is this possibly a connector to the hose I see going into the back of the engine?

blktoptrvl · #9 03-20-2017, 02:19 PM

OK, I have taken care of other things I had to do. It is now time to turn my attention back to my X5.

I have a couple questions about the N62...

All the post I read about the transfer pipe include removing it by cutting out the old one and installing a new one. Cutting out the old is supposedly done in order to not have to take the front of the engine apart. What does this mean? Is it a matter of just removing the water pump or is there much more of the block that has to be removed? (Edit: I see the timing chain covers must be removed - is that all that difficult)

The Bentley book (M62, not my N62) indicates that the coolant pipe can be removed, the seals replaced and the original pipe put back in. So, why are so many people going to the expandable replacement pipe?

Any help? Any insight is appreciated.

Does anyone know of a complete kit... Transfer Tube/Valley Pan Gasket, Intake gaskets, everything else...

williamx5 · #10 03-20-2017, 09:45 PM

Quote:

Originally Posted by blktoptrvl

OK, I have taken care of other things I had to do. It is now time to turn my attention back to my X5.

I have a couple questions about the N62...

All the post I read about the transfer pipe include removing it by cutting out the old one and installing a new one. Cutting out the old is supposedly done in order to not have to take the front of the engine apart. What does this mean? Is it a matter of just removing the water pump or is there much more of the block that has to be removed? (Edit: I see the timing chain covers must be removed - is that all that difficult)

The Bentley book (M62, not my N62) indicates that the coolant pipe can be removed, the seals replaced and the original pipe put back in. So, why are so many people going to the expandable replacement pipe?

Any help? Any insight is appreciated.

Does anyone know of a complete kit... Transfer Tube/Valley Pan Gasket, Intake gaskets, everything else...

Check out page 11 about half way down (post 106)... I had already put the coolant pipe in and cover on, but had to take them back off due to not having a warm an fuzzy about the pipe sealing to the front timing chain cover...

https://xoutpost.com/bmw-sav-forums/...roject-11.html

I am running the motor now and actually took it out today despite the transmission having a slight cold... It's okay as long as I don't throw a lot of power at it... It doesn't do well with fast shifting... So, while my method might not be factory, I think it is as good OR better than what BMW had planned... There is a good picture of the whole motor completed I think on page 12 or 13... You can see the white sticker on the new short pipe that connects the valley pan to the water pump area...

Cheers!!!

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