2003 x5 Coolant Leak
 

Hope smoeone can give me an answer to what is leaking coolant from between the bellhousing of the transmissiom and the rear of the engine. It not dripping on the ground when i park the vehicle just a thick sludge at the bellhuosing.But i have to add coolant to the expansion tank every two weeks or low coolant warning will appear in the instrument cluster.Guess it leak when i am driving.An answer to where it leaking from will be greatly appreciated.

A common culprit is the expansion tank itself. Try to trace the flow of the coolant although it could be tough to see. Many of us have had to replace the tank. I replaced mine and I could not find any obvious cracks but it was definitely leaking. I was having to top up coolant daily and there was quite a bit of coolant congealed on various parts below the tank.

It might not be your tank but if you decide to change it, I would change out some hoses, the cap, and the level sensor while you're at it.

Your Valley Pan is probably leaking, I just replaced mine.

Other possibilties are the coolant return tubes, the rear coolant manifold or one of the hoses on the rear coolant manifold.

There are several threads and a DYI on how to fix it.


Good luck.

:iagree: Valley pan. The valley in the middle of the engine has a cover which is prone to leaking. When the coolant seeps out of the cover, it pools in the vee of the engine and can mostly evaporate, leaving you wondering "where did my coolant go??" If the coolant leaks enough it will drop out of two drain holes at the back of the vee by the firewall and then go down by the bell housing. I'm pretty sure that is what you are seeing.

Check the DIY for the valley pan repairs. The updated valley pan is relatively cheap ($11), but the repair is very labor intensive and you have to remove the intake manifold, water pump, coolant manifold, etc to get to the pan. It's a good opportunity to replace many parts that will commonly fail (water pump, thermostat, rear manifold gaskets, Oil separator, hoses, etc.

coolant leak 2003 x5
 

I have been investigating the leak and the position where it coming from and i have to agree with TRIX5 about the vally pan making a mess of itself. So now come my DIY and to know all parts to order before i started, seems like i got to move alot of things out the way.Thanks alot for the help so far.Question now is where to order parts from and get the correct items for the job.Any advise on that will be greatly appreciated again Thanks alot. Was driving me nutts!!!! trying to find just what the heck was leaking behind there.Was thinking heater core and was about to take that out. My location New York USA thanks.

Where can I find these DIY? I check the DIY, didn't see anything.

If it's a V8, definitely valley pan.

Check heater hose #11 and #12 first. See diagram below...

Ok thanks will check heater hose #11/12 also thanks for the diagram,and yes it is a 4.4i.

http://www.xoutpost.com/article/BMW%...n%20Gasket.pdf

Is a good starting point. But there a lot of threads if you search "valley pan".

was just about to do my valley pan gasket and want to make sure that I get the right part. Is it #1 or #3 in this diagram?
RealOEM.com * BMW E53 X5 4.4i Engine Block Mounting Parts
I should have done it while I had the manifold off a while ago replacing those rear coolant hoses and valve covers.
Since this is a huge chore, can anybody suggest anything else while I'm back there again that probably should be replaced (140k).

Also, I remember looking at those two pipes that run above the pan and thinking that looked tough to get them out. Anybody have a preferred way to go? Maybe I should just replace the water pump a 2nd time and take them out the front?

Last question. I remember that hose coming out the bottom of the OSV being fairly pinched back there, wherever it goes. Important? I remember trying to assess what the OSV really does, 2 lines from the top of either head I believe and then the one hose that disappears below...

It's number 1 in the drawing. It's a cast metal pan with an integrated rubber bead gasket. #3 is just a snap on plastic cap to go onto #1, you don't need to replace it.

Re: the OSV hoses... Yes very important not to pinch those. They can get clogged anyway with oil/water sludge and if there's a restriction in the hoses it will be more likely to get a pressure buildup.

I would replace the Crankcase vent Valve attached to the back of the intake, along with a new oil separator and new hoses below the oil sep, and the two above the oil sep. Just good insurance going into winter since mine have blown up in winter and caused vehicular fibrillations and migraine headaches!

It's easier to go from the front on the water pump side. Get new o-rings for that. Assuming you've already done the rear coolant manifold.

Where did you see that gasket for $11? I can't find one less than $70...

Do you mean replace the whole rear coolant manifold? or just it's gasket?

Well... Looks like you're right. The lowest I see now is $68.95.

http://www.autopartswarehouse.com/sh...et/bmw/x5.html

But I swear it was cheaper a few years back. I did mine in 2007.

Re: the rear coolant manifold, just replace the two gaskets, left and right. Reuse the manifold.

If you're doing the coolant manifold remember to take out the cabin air filter housing assembly above the firewall so that you'll have room to work around at the back of the engine. Easy to remove.

I am not going to say it's definitely the valley pan, but that is the same problem I had with mine.

Eureka!
 

Haha, yes I should have done more research before I did all that work originally. I was on top of the motor for a few mins like a monkey f***** a football til I had that same epiphany. It comes out so easily I rejoiced and had 3 beers. I'm still not looking forward to replacing the hose that comes out the bottom of OSV. Then someone mentioned gaskets on the back of the intake manifold, coolant running in there as well?

I have to do this repair soon. Not a fun way to spend a weekend.

I would be willing to bet a steak and a cold beer that it is 100% the valley pan gasket.

Even if you have another leak I can promise you that yours is leaking. So either way I win. While you are in there go ahead and get valve cover gaskets and do those too if you have not because they will be leaking on you sooner than later.

If you guys had to put a dollar # on all the parts needed to repair the valley pan, seals, water pump, etc what would you say it is? Assume no labor costs....just materials. Are we talking less than $500?

Vally Pan
 

If your vehicle is maintain proper and you are doing just the vallypan parts will be lest than $500 If your vehicle is anything like 2003 x5 4.4i you dont have to move anything on the firewall dont have to move water pump or valve cover either. All you need to do is drain your antifreeze remove the intake manifold removing the intake manifold is the hardest part of the job everything that connect to it got to be remove then used a mirror and a 10mm socket to remove the water manifold at rear of engine take the water manifold and water pipes out that way so you dont have to touch the water pump you may need to change the water pipes (check the ends on those pipes make sure they will seal proper) added coast if they have to be replace I did not replace, mine was good but the Orings got to be change. After removing the water manifold and water pipes the vallypan will be there for you to remove.(Very Important to remember when you remove the intake manifold use paper towels i use that blue shop towels that sell at any auto parts store TO PLUG ALL INTAKE PORTS keep dirt, tools, parts or anything from falling in those Ports. You can also get a injector repair kit what you need is those little plastic washers at the bottom they crystallized and crack.Igot a kit on Ebay for $30 that kit is hard to find the orings are easy to find those little plastic washers are hard to find.Have fun O one more thing enjoyed the cleaning it will be a mess in there good luck.

Just an update on my vehicle.....turns out the leak was due to a failing water pump. I was driving yesterday and the pump decided to die, which took out both sets of drive belts......snapped and shredded. So, had to have it towed back to the house. Currently tearing apart the front part of the engine to replace the pump, t-stat, hoses, etc.

Mine is doing the same thing however when the tech looked at it he said it was the Rear Coolant Cover, not the Valley Pan leaking...

Hey guys, I'm having some coolant leakage myself. I'd figure I'd piggy back on this thread and not post another coolant thread.

The other day my check coolant level indicator came on which surprised me because I changed the coolant reservoir several months back. I just noticed some coolant spots on my driveway today where my x5 is parked. The x5 is parked on an incline so I'm assuming the coolant dripped back several inches before reaching its destination (the ground). The spot on the ground is probably a couple inches behind my radiator or the coolant reservoir. I know the valley pan is prone to leakage but I have no idea where that is. Could that be the culprit in my case? Or is it more likely that it is leaking from the radiator? I was looking at the hoses that run from the reservoir and didn't see any signs of leaking (dried white spots).

Oh and it's in the middle but more on the drivers side. The x5 is a 2002 3.0 Thanks!

Ace,

Check the thermostat or the waterpump. They both are prone to leak on either a 6 or 8 cylinder engine.

Hey wrench,

Thanks for the quick reply! Where would I find the thermostat or the water pump? Do I look from the top or the bottom?

The water pump is driven by the belt and is in the center of the engine. It will be directly above the crank pulley and has about a 5 inch diameter pulley on it.

I think I found it but didn't find any signs of leakage. I'll take a closer look tomorrow when the weather is a bit warmer. Thanks wrench!

Just an update, I just had the water pump and thermostat replaced. That seemed to be the culprit. Thanks wrench!