coolant leak

we350z · #1 11-24-2009, 10:22 PM

belly pan = skid plate ? The big bare metal looking cover thing? Is this easy to remove? I would imagine it would make tracking down this leak a little easier. Hopefully I have the right bits (i think i have just about every torx size after doing the hitch installation.

Quote:

Originally Posted by HPIA4v2

I'lll jack the car up and take the belly pan off. If there is anything dripping, it'll hit the floor so it's easier to see (instead of get collected on the belly pan)

HPIA4v2 · #2 11-24-2009, 11:33 PM

Quote:

Originally Posted by we350z

belly pan = skid plate ? The big bare metal looking cover thing? Is this easy to remove? I would imagine it would make tracking down this leak a little easier. Hopefully I have the right bits (i think i have just about every torx size after doing the hitch installation.

No not the metal thing, it's the black plastic further forward. You don;t need torx to remove the plastic belly pan.
If you have V8 and your valleypan gasket leaking it may get collected on that metal cover thing, but I'll start with the easier thing to take off (my rule in fixing car problem

).

we350z · #3 11-25-2009, 01:05 AM

OK got it. Hoping it's a hose, when I squeezed the upper one yesterday it definitely felt a little bit brittle.

Should I be able to get a visual on the water pump after removing this belly pan in addition to the radiator and hoses?

I guess if it's none of those or the reservoir then it might be the valleypan gasket leaking?

Quote:

Originally Posted by HPIA4v2

No not the metal thing, it's the black plastic further forward. You don;t need torx to remove the plastic belly pan.
If you have V8 and your valleypan gasket leaking it may get collected on that metal cover thing, but I'll start with the easier thing to take off (my rule in fixing car problem

).

HPIA4v2 · #4 11-25-2009, 02:16 AM

My upper radiator hose developed small crack, I saw the low coolant message on the way home from work two-weeks ago. Pulled into the garage, turned the engine off and heard the hissing sound and small steam coming out of that crack. Temp was normal throughout, added about half gallon distilled water to check how the situation was. I ordered WP, all hoses, thermostat the next day. So if you still onthe original hoses, you may want to replace them. For reference, mine has been garaged all the time and Seattle is probably not as hot as Arizona climatewise.

For WP, you don;t need to remove radiator, just the fan clutch and belt to spin it to see if the ball-bearing still smooth and see any leak around it. But at this time it's probably not a bad idea to replace WP and thermostat. FYI, mine @58000 miles (8 year old) the WP and thermostat look like new.

Hard to say if you have valleypan leak or not, I heard from E38 740i people that parking on incline will make the leak from valleypan worse, so something you can check if you think it is.

Good luck.

we350z · #5 11-25-2009, 04:40 AM

Well I removed the belly pan plastic protective splash guard cover thing from underside front of the vehicle and I can see the condensation right away even after the vehicle has been sitting for over a day:

I'm not 100% positive but from what I can see I think it might be the water pump that has sprung a leak. Is the WP directly above the underdrive (large) pulley? I filled the empty reservoir once again and started the engine. Once the water temp started rising a little bit I could see the spray on the ground from the coolant on to the fan.

It looks like there is some fluid pooling on the ground around the center right (towards driver side). It is brown, i think either from rust or dirt or something but definitely is coolant/water.

It looks like its dripping off the bottom housing piece for the small pulley (tensioner?)

A little bit closer inspection with the flashlight I can see some spray up above the underdrive (larger) pulley. Is this where the water pump is located?

You have to look closely but you can see the moisture:

Even closer:

Negritoamni · #6 08-28-2010, 09:08 AM

If you do remove the plate for inspection, do not drive without it ,some of the bolts secure the sway bar...
Your best bet is to pressure test the coolant system, this will show you where the leak is...And if you can`t see where it is coming from...This is where it gets complicated.
Under the intake manifold there are coolant tube(s) that connect to the rear coolant pipe (connected to the rear of the heads) this tube(s) have O-rings that get stiff and will leak under pressure. The bad news is it very difficult to see in this area w/o taking parts out.
Good luck