Coolant Leak
 

Hey All,

So, another issue has just presented itself last night. Just as I'm getting home, the "CHECK COOLANT LEVEL" popped up. Previously I've had to top it off, and haven't seen that message for 4 months.

Tonight was different. As I pulled into the driveway, "fog" was coming from under the hood like an electric plant heat exchanger (it was below freezing)! Something let go on the passenger side (right, US model) on the engine near the rear. We removed the engine cover, turned the heater on/off, but aside from a clear amount of coolant in the engine compartment, on the bottom of the engine cover, and the firewall, we couldn't find any leaks.

I've tried searching the forum, but search isn't working for me (just tells me I need to wait between searches), and I didn't see anything that stood out on RealOEM. What is on the back of the block on the passenger side that could have failed and purged coolant?

We checked all the hoses we could see, but nothing was leaking.

I would start by checking the hose clamps on the hoses going to the back of the engine first. Those hoses go into a manifold that bolts to each head. There are two gaskets for that manifold.

Could be the valley pan gasket, but those leaks usually come on slowly.

There's also a plate (with a gasket) on the back of the engine, between the transmission.

@Helihover - I'll see if I can't get a better look at the rear to see the hoses and clamps. We didn't see anything last night, and we couldn't find anything leaking. I'll see if I can't get a better look.

Not thinking the valley pan, should be a much slower leak not a purge with coolant everywhere. The gasket on the back between the transmission was looked at when I had the transmission replaced 2 months ago and the shop said it was fine. Of course with my luck...

I just went through this on my X. Here is the suggestion if your X has over 85K or is over 10 years old you need to just bite the bullet and change all of the vehicle hoses. Reason being you will just be chasing one leak after the other with regards to coolant and you don't want to waste the precious blue coolant. I ordered all of my hoses for the 4.6is two weeks ago and just installed them earlier this week. There are a lot of hoses so lots of potential points for leaks.

Jay - That is actually my plan long term. I've seen some kits on AutoHausAZ and ECS Tuning that appear to be complete cooling kits. I've always had issues with cooling in one way or another on my BMW's, so I was going to take the pro-active approach and just replace everything. I just wasn't planning on doing that NOW, but closer to about 6 months from now after we get a house and I get my garage back I can work in.

Okay I understand completely and your on the right track. Don't forget to change the thermostat for the trans cooler and the coolant hose connected to it. I forgot this one so I will address it with my front cover oil leak repairs scheduled for after Christmas. I am like you I do not play with coolant problems on a BMW. Whenever I get one that is over 10 years old and original, I run through the entire cooling system for piece of mind.

So I picked up the X5 last night. The dealer didn't do any fixes but they did diagnose all the issues. A couple of coolant hoses are leaking with only one really badly. However, I can't relate the hoses they're talking about with anything on any site, or RealOEM.

Per the work order:
-"Hose from the engine inlet to the water valve" (badly, making the X undriveable)
-"Connecting tubes for the heads"

They also mentioned the valley pan gasket, but I knew that one was leaking slowly. I'll be doing that and the valve cover gaskets next year as part of a big overhaul. But, I have no idea what they're talking about with the 2 hoses listed. I've checked various sites like ECS and BavAuto, and even RealOEM but nothing talks about an engine inlet to water valve or any hoses running between the heads.

Any help here would be very appreciated so I can get the X5 back up and running. With winter and snow going full bore here, my Tundra is not nearly as good as the X5 in these conditions.

TIA for any assistance!

OK, so I found the inlet hose I think, it's just not part of the cooling system it's part of the heating system.

RealOEM.com - Online BMW Parts Catalog

I believe it's part #11 that I need to fix the massive leak. Still not sure on the hoses that run between the heads, but right now my priority is to get it fixed so I can drive it again. :)

Reaching the hoses going to the back of the engine, the ones you are about to replace, are much easier to reach with the intake manifold off.

If I were you I would do the VPG with the hose repair. You don't have to remove the water pump/fan ect. For the VPG repair all you need is a tube of gasket maker. However, I would recommend replacing the 4 orings on the two pipes above the valley pan along with the intake gaskets. I didn't plan on replacing my intake gaskets, but they were pretty hammered, so......

If you start early, this is an easy one day job that is really not that expensive.

Helihover - I was always under the impression the VPG was a massive PITA? Is it not that bad, just labor?

This summer I was going to do the VPG and the entire cooling system. I was just going to grab a kit like those that Turner has. Turner has one that also replaces the CCV and the whole kit is $277, or $195 without the CCV replacement. If I'm taking the intake off though, I might as well do the CCV at the same time.

Valley Pan Gasket Kit - E53 X5 4.4i, 4.6is 2000-2003 - Turner Motorsport

My cautious side says get the kit and just replace stuff since I don't think the PO took care of the vehicle. I have access to a garage and tools (gotta love in-laws!), and I'm used to working on vehicles so I don't think it'd be a problem.

I was also going to do the valve cover gaskets at the same time...would those be easy with all this taken out for the VPG and should I just do that maintenance now? The two gaskets are only $50 in parts, and if everything is out of the vehicle anyway...