2004 4.4i coolant leak
 

Hi guys,
It seems i cant catch a break. Now my car is dropping coolant.

Its bit of a strange one though, when the car is running or even warm it doesnt appear to be leaking. It only seems to be when the car sits for a few days.
If the car sits in the driveway for a few days there will be a big puddle under the engine and the "check coolant" warning will appear and I need to add fluid.
If i continually drive the car and not let it sit it is fine and will go a weeks before i need to put any more fluid in (usually because i let it sit a few days and get the puddle under the engine)

I am finding it hard to find out where the coolant is coming from because it only leaks after sitting for a while. Has anyone else come accross this?

The leak is hitting the ground towards the front left of the car but it might be flowing along the bottom engine bay cover and coming from anywhere.

Any ideas?
Seems very strange it only happens when the car cools right down.

If you are lucky its the expansion tank. Just replaced mine and when off, you can see clearly the leak around the seam at the top. You could not see this with tank in car, it has to be upside down to see it.

Cheap at $75 and a 10 min job

David

Ok i'll pull the expansion tank out and have a look.
Was yours leaking all the time or only when the car was cold as well?

I pulled the expansion tank out and couldnt see anywhere it was leaking.

I let the car sit for a couple of days again to let the cooland flow out. I tried to find where it was coming from but looks like it could be coming from the back of the engine as the coolant was on the floor just behind the front right wheel.

Is this signs it could be the valley pan gasket leaking? Any ways i can confirm if it is this or not?

Just replaced the radiator on my 4.4 as it had a small crack on the top right hand plastic just below the pipe. Will be keeping an eye on the level and hoping that it isn't the valley pan gasket, as this will be a right pain to change cos of the LPG system.

Just replaced my coolant tank - split on the corner top to bottom. Wish I could have got one for $75 - cost me $220 and BMW quoted $320. Replaced it myself, easy job.

Mine had same symptoms. Was leaking only when it sit for few days and I got message. I think it was leaking from the plastic under Intake manifold.

Can you tell if the fluid is coming from the back of the engine or the fire wall. The back of the engine is a sign of the Valley Pan gasket, the firewall would be a sign of the heater along the firewall leaking.

James

My guess is valley pan. Try this, remove the cabin filter assembly to allow you to check the rear of the engine and firewall. The procedure should take all of 15-20 minutes and gives infinitely more room to inspect.

http://i1083.photobucket.com/albums/...lyRemoval2.jpg

The Leaking Rubber hose on the back of the engine has been replaced. There were also little rust on the bolts of valley pan. So that's all I can say. I spent a whole lot of effort fixing my car and however it ran great (vs other M62) also. However it now has a new owner and is in good hands. Waiting few months on 4.8is now :P Going to fix all theese alrady known to me issues before taking on the highways. Cheers.
P.S. I would inspect valley pan gasket, If that is leaking I would realy do Valve Cover Gaskets as well.

I have the N62 engine in mine.

On the weekend i'm going to pull out the cabin filter assembly and see if i can see anything.

Nik,
You had the same symptoms as me, did you have a dealer repair it or did you tackle it yourself? Was it a hose or the manifold itself that was leaking?

You will need a mirror I guess. I suspected a simple hose leakage when I had my Motor out, But I didn't make my statement clear, It didn't fix the problem. I'm 80% sure it was valley pan gasket.

Wydra,
I am experiencing the exact same issue as you have described in your initial post on this subject. Coolant Leak after car sits for day. Then top off. Then a few days later, same thing again.
I have replaced my expansion tank & cap about a year ago.

Did you ever eventualy find the source of this problem, or a solution that stopped it.

Thanks!

SkidmarkX5

Well yes and no.

To this date I have not "fixed" the issue.
I have ordered the valley pan gasket and am going to install this (and inspect everything else back there while i have the cabin filter assembly removed).

When i get around to doing the work i'll jump on here and let everyone know what the issue was.

Thanks for the prompt reply.
Currently, my splash guard is removed & so I suspect my coolant is indeed comming from the bottom front of driver's side. That is pointing right at the silly expansion tank. I will place some papeer towels under this area and see if I can localize it further.
Will notify when I figure it out.

Best regards...

Any updates here? I have the same issue....4.4 thanks

Have an Appt. w/ indy to Pressure test Tuesday, 12/20. Will notify.

results???

I think I am having the same issue, I notice the lower small hose that connect from radiator in front of the radiator fan has a leak, but not too much leak. When I park the car for a few days, I notice some coolant on the ground. What a cheap BMW engineer who designed this car!!

Mod should kill this thread.... too many hijacks

mike_dmt... unless you have input in the thread maybe you should keep quiet.

I started this thread and most things said to date (besides your post) have been about the problem and information towards it.

Keep the thread alive!

It is summer here in Australia and the leak seems to have basically gone away. It seems to be something that only occurs when the engine gets very cold (hence why it happens after a couple of days of no use).
Im sure when winter comes back the leak will re-appear and i'll be looking at this thread to see what others have done and what i should do to fix it.

my 2c.
Dale

Your best bet to isolate coolant leaks is with presure test.
So many places on BMW V8 to leak, o-ring, gaskets and hoses etc. I thought I had VP gasket leak (signature symptoms, leak at bell housing only after cool down etc). It turns out to be o-ring of the coolant pipes pinched after WP replacement on M62 engine (N62 has one pipe tha leaks as well and even harder to get to).
this is the kit I bought (could've saved me hours of work):
Radiator Pressure Tester Kit