Ok. I need some help narrowing down my newest coolant leak on my '04 XJR.

Background:
I've replaced the following over the past few years.
- Thermostat housing
- Upper Hose
- Lower Hose
- Intake Hose
- Water Pump
- Drain Hose
- Return Tube

Symptoms for new leak:
- Only leaks when it's hot
- Doesn't leak all the time. It will leak about 8 oz then stop. I can run it at idle for a long time after it stops leaking without subsequent leaking. However, if I drive it around the block and come back, I get a new 8 oz leak.
- It's on the front passenger side. The leak pours out around the right hand side of the oil filter.
- It doesn't appear to be coming from the water pump.
- I get a small squeal until the car warms up, which goes away. From other forum posts, seems like this is due to wet antifreeze that evaporates as it gets hot.
- Seems like the antifreeze is traveling up the passenger side belt and depositing some of the antifreeze around the passenger side supercharger inlet/outlet hoses.

I read something about a cracked nipple in the expansion tank. I'll go check this, but it just seems like the leak is somewhere lower in the engine compartment. Is the expansion tank always getting refilled when hot? Or is it getting periodically refilled? The problem is obviously with a hose that is periodically pressurized versus one that is in constant use.

Mark

 

I found it! Boy, sneaky little devil.

The line that runs from the thermostat housing back over the top of the supercharger to the back of the engine is the one. It had a little pinhole leak right where it joined the housing just behind the supercharger pulley on the bottom of the hose. It's the left hand hose when looking at it from the front. (The rightmost hose)

Now the next decision point. Is there enough slack in the line to slice it behind the leak and re-connect, or do I need to replace the whole line? If I replace the whole line, how the heck to I get to the back of the engine? Do I have to lower the engine somehow?

Perhaps a good temporary fix is to splice in a metal joining tube so I don't have to replace the back half?