I noticed that the coolant level in the reservoir had dropped, so I looked for a leak. All hose connections looked dry, so I used my pressure tester on a cold engine to check again. Pressure remained at 15 psi and only slowly fell after about 10 minutes to about 10 psi. H-m-m; slow leak somewhere else?
I topped up the reservoir and drove a few miles. I left a piece of cardboard under the car overnite, and noticed a puddle the next morning. I jacked up the car, removed the front right wheel and splash panel. Sure enough, I saw that the coolant pipe behind the exhaust and the oil pan were stained.
Looks like the water pump is leaking, but I'm surprised because I replaced it when I replaced the head gasket at 95K miles. Now at <170K, I'm not happy that an aftermarket Bosch water pump should fail at 75K. I inspected the timing belt, but it looks dry, though it makes sense that any leaking coolant would be flung off.
Also noticed that once the reservoir is empty and the radiator coolant level has also dropped, that the leak rate is much slower. Is this a case of the coolant level in the system dropping below the level of the pump?
Only way to know for certain is to disassemble the timing belt and check the pump. I don't plan keep the Eclipse much longer (has a few dents and paint is faded), so is there a risk in not replacing the timing belt (due in 25K miles) and pulleys while after I disassembled everything? Probably will replace the accessory belts as they're not expensive.
#138380, "RE: Leaking coolant" In response to Reply # 0
I can't visualize where the leak is, when you say it's behind the exhaust. Can't be the water pump if your leaking slows down only after the reserve container has emptied, it has to be higher on the block. A common place where leaks can occur is the little rubber hose that comes off the thermostat housing and goes over the exhaust shield in front of the block. It's subjected to a lot of heat and needs frequent replacements.
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#138383, "RE: Leaking coolant" In response to Reply # 1
Thanks for your note, EZ. I checked the short crossover hose above the exhaust manifold cover and it's not leaking. When I replaced the head gasket a few years ago, I forgot to tighten one of the hose clamps and that hose leaked, the discovery of which was a load off my mind, as I was afraid that I had screwed up installation of the new water pump. When I last replaced that hose due to a small crack at the clamp, it was almost as hard as ABS, probably because of heat deterioration.
#138410, "RE: Leaking coolant" In response to Reply # 0
The failed (at <75K miles) Bosch coolant pump has been replaced. The impeller shaft seal failed, though the bearing felt as tight as new. It looks like the cast pump housing took failure mode analysis into consideration, as there's a small spout that directs coolant leaking past the seal downward and away from other parts.
I purchased the Gates TCKWP246B coolant-pump-with-timing-belt kit at Amazon for <$123. Also replaced the alternator belt and the power-steering-and-AC accessory belt.
Also replaced the front shocks with KYB GR2s.
Lastly, in addition to engine oil and filter, I had the transaxle lubricant replaced with Walmart's ATF+4, sold as Super Tech. It's licensed by Chrysler, the developer of ATF+4: http://centerforqa.com/chrysler/licensed-atf4-brands
Definite improvement in shifting the NV-T350 transaxle.
