This just isn't my day. While poking around, looking for obvious ABS sensor issues, I found some coolant on my sway bar.

This correlates to a slow coolant leak I've had for about a month. I havnt experienced any high heat issues and couldn't visibly see coolant anywhere (until now) so I haven't been sweating it too much, just keeling and eye on the level.

The reservoir is leaking slowly from a pin hole in the bottom. No stress cracks or obvious defects, just a random whole that drips slowly when the vehicle gets to operating temp.

This is the second replacement reservoir I've used. The first one leaked at the collar where the filler neck meets the reservoir. I eventually figured out that I had a blown head gasket, so I'm not sure if that one leaked as a result of high water pressure, but it was at a seam in the two plastics, this reservoir is leaking from what appears to be a solid piece of plastic.

now I'm wondering if I've got another headgasket leak that's overpressurising the system again.

No overheating, and no coolant coming out through the purge line...
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I had similar experience and I had replaced tons of those plastic reservoir because of the same problem but never been related to head gasket. BUT, you should check if theres another leak thats dripping to the swaybar, might be behind the engine, just to be sure.

 

It's definitely from the reservoir. I lifted it out of its perch and watched it drip. It's rolling down the inner fender and onto the top of the sway bar.

Has anyone seen an aluminum reservoir used? There's one available as a direct replacement for a D1 but I can't find one for a D2. I'm willing to bet someone has made one work before.

 

Yup, there is an aluminum tank for the D1. Cant that be retrofitted to a D2? I think the aluminum tank wont be a good idea since youll not be able to see the coolant levels at a glance. Unless you redesign something with a glass level for boilers.

 

I'm not sure about retrofitting the D1 piece, does the d1 have a pressurized reservoir or is it just an overflow like a traditional system? There are a bunch of aluminum reservoirs with the glass/ plastic tube on the outside for level checking but its not readily apparent whether or nor any given reservoir is OK with pressure or not.

 

https://landroverforums.com/forum/discovery-ii-18/new-expansion-tanks-keep-leaking-60776/


​​​​​​Obviously this is a common issue. There's a bunch of reports like this one ^^^. I just wish I could find a definitive cause. Seems like one of those problems that is never addressed entirely. People either just keep fixing it, never have the problem, or never report back with a definitive cause and remedy.

Is the system over-pressurized from combustion gasses? Is there a tiny leak that is causing the coolant to become acidic? Is there latent dexcool still circulating which so causing acidity? Is the reservoir cap not releasing pressure like it should? Are these reservoirs just Chinese bull**** quality?

 

If wondering too far you may get lost. Fix what's broken and keep your eyes open.
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doing my best to stay calm and slow roll my way through these small problems.

I decided long ago that when the time came for another head gasket fix, or a slipped liner situation, i was going for a full top hat rebuild and all the fixings. I was hoping to go at least a couple years before having to dive into that pool, enough time to gather another block and build it slowly, so anything even remotely related to a possible combustion gas leak gets me wound up pretty tight.