Coolant Leak - WJ V8

[Hanna]

Hi all,

I noticed yesterday my WJ has developed a coolant leak. It has never leaked coolant externally before (head gasket is/was leaking at cylinder No.8 - but that's another story ) and I just noticed it yesterday when I backed it out and parked it in the street.

It appears to be leaking from underneath the alloy neck that connects to the top radiator hose (i.e. directly below the alternator) and is dripping down over the water pump housing and onto the ground.

Most cars I have worked on in the past have a weep hole on the water pump where coolant leaks if the water pump seals are stuffed. Could this be where the leak is coming from? Anyone out there had a water pump go on their WJ V8?

Additional info: I replaced the coolant a couple of months ago with same Nulon red stuff that was in it. Reason being as the head gasket was leaking (running rough on start-up and losing coolant internally) so I ran some Chemi-weld through it and then drained, flushed the cooling system and put new coolant in. Since then it hasn't been losing any coolant and has been running fine on start-up. I know this is not the best thing to do but I niether had the time or money to change the head gasket immediately.

Just want to know if it's the water pump that needs replacing and if so I will just stop procrastinating and rip the head off at the same time I am replacing the water pump, and hopefully all will be sweet again. Reading the "Coolant Change" thread makes me concerned that putting the new Nulon red stuff in it may have attacked any weak point in the cooling system, i.e. the WP seals.


Cheers,
Hanna

[turbomart]

If its leaking from above water pump then it cant be water pump, water cant go uphill.Id check top rad hose make sure its not weeping out underneath.It will often run down/along something then drip off somewhere different, often nowhere near leaks origin.

[jzp]

Careful with the coolant you use - apparently the electrolysis is a killer with radiators in your car... you need to use the Mopar stuff.

[drover]

Any HOAT coolant that meets MS-9769 does the job, problems occur when the mix is incorrect and/or crap water added. 50/50 is recommended and covers the temps we have here.
Using any Stop Leak product should only be used to get out of trouble then clean it out and fix the prob, leaving it in for any longer can lead to other hassles, especially with all the differn't metals there nowadays.
Hope its just a hose clamp.

[nzdans]

Originally Posted by Hanna

Most cars I have worked on in the past have a weep hole on the water pump where coolant leaks if the water pump seals are stuffed. Could this be where the leak is coming from? Anyone out there had a water pump go on their WJ V8?

As of today I think I can say yes to that. The grand had a few firsts on Monday in the Wombat State Forest; tyre de-bead, stuck in bog hole, bog hole water flowing in when door opened .. not sure if these contributed much. I gave the car a bath yesterday including a good blasting under the bonnet so when the V8 ran a bit more like a 6 and could hardly idle on the way to work this morning I figured maybe I'd gone too hard with the water sports. Got home from work to be greeted with coolant on much more of the car than usual..

Green highlights:


So this weep hole you speak of, does it look anything like the offending orifice below? Am I safe to assume that a new water pump should be on my shopping list and that it was the cause of the crap engine performance? I didn't pay attention the the temp as much as usual today as I had the heater / fan on full blast trying to dry the carpet so figured that would keep things cooler (could have also contributed to the failure?). I did notice the temp to be higher than usual when I pulled in the driveway (circa 103), coolant and oil look OK, I think..

[Jeep_Nut]

Yeap that's the weep hole top water pumps main body

[Hanna]

Hey NZDans,

Yeah mate - that's the weep hole from the water pump and it means your water pump is stuffed.... I installed a new one when I rebuilt my heads and it was pretty cheap from Rock Auto. I can get the part no. for you if you want?

Changing the water pump shouldn't be too bad as long as you can do it without removing the radiator and shroud. I can't remember if it can be done or not without this. I certainly wouldn't be driving it anywhere until it's fixed because all it takes is 1 minute of overheating and your heads will be warped.

The rough running scares me a bit.... Was it running rough prior to the engine clean, or only afterwards? If it was only afterwards then hopefully you've only got some water somewhere in the electrical system that you shouldn't have. If it was already doing prior to the wash it then could (amongst other things) indicate warped heads as it will let coolant into the cylinders causing misfires.

I have my fingers crossed for you mate! Let me know if you need any further advice - happy to help.