2004 4.4i coolant leak

[wydra]

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.

[nrgetic99]

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

[wydra]

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?

[wydra]

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?

[swipe]

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.

[amc1957]

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.

[Nik]

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.

[ECS Tuning]

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

[xmac]

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.

[Nik]

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.