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Back in May I had an issue with disappearing coolant. I could never find any puddles of leaks. Immediately I assumed head gasket. I've done the usual tests of checking the oil, checking the coolant etc and there's been no cross contamination. I bought a radiator tester to see if any exhaust gasses were in the coolant. There was not. I tested twice. Just recently I started noticing missing coolant again. Turns out the overflow tank is ridiculously full. I replaced the stock radiator cap with a different one that has the red lever style, this was done back in May. It clearly is not moving back over to the radiator.
Head gasket? What else could it be? And yes the lines are routed properly.
ZERO overheating issues no noticeable leaks
98 bolt on LS1 PRC 799s
The red lever cap is not a recovery cap in most cases, its one way - OUT only.
if you have the factory style recovery system you need a recovery style cap.
Doesn't sound like any kind of head gasket issue to me. The coolant is not disappearing into the oil or out of the exhaust, it's just getting pushed into the expansion tank (normal) and then not pulled back as the radiator cools (not normal). So perhaps the recovery hose has a breach, or the nipple is damaged, or the cap is bad/not correct (as mentioned above).
I did have the same problem with the stock cap which is what brought me to this one. the old one had some cracking in the rubber surround/gasket material. This one could definitely be completely incorrect and it's a theory I had as well.
I pulled the expansion tank tonight and looked all over it, tilted it numerous ways, just to see if it had a crack somewhere, especially the tube section and upper areas of the tank. All was good, the hose looks good as well. But i will double check that in the morning.
Apparently that was just the beginning.. lol. Replaced thermostat o-ring and still had coolant loss. Another pressure test showed this. I think it's the water pump itself and not just a gasket.
I had a very slow coolant leak for months and could smell coolant without seeing puddles or finding the source. Finally pressure tested it, but it revealed nothing with the engine off. However with the engine running, noticed a very small leak coming from the bottom of the water pump. Replaced with a new LS2 pump (old pump was installed around 2006), new gaskets, new hoses, new stat & housing, just to try to eliminate any loose ends. Smell is finally gone.
Apparently that was just the beginning.. lol. Replaced thermostat o-ring and still had coolant loss. Another pressure test showed this. I think it's the water pump itself and not just a gasket.
You're just full of good news! Are you certain that its the pump and not the coolant crossover? Does look like it's in the area of the weep hole but either way it shouldn't be too much trouble to fix.
You're just full of good news! Are you certain that its the pump and not the coolant crossover? Does look like it's in the area of the weep hole but either way it shouldn't be too much trouble to fix.
Welcome to my life. I've been working in a different city and when i came home:
Camaro losing coolant
Pacifica losing coolant
Camaro hatch struts failed
Yeah i replaced all the coolant crossover gaskets and all is good there. I think it's the weep hole, which means new pump.
Sounds like the LS2 pump is the way to go since I'm going Procharger.
The moral of the story is that coolant can drip slowly or intermittently from the weep hole for a long time before it really becomes a problem. It burns off, so you smell it but don't see any puddling on the floor. Once you do, it's time to replace the pump.
I've done it twice on my A4 car, at 104k and 175k, but my M6 car at 89k is still rocking the original, though I get the smell occasionally. But it's only driven 5-600 miles a year, so not a concern.
The moral of the story is that coolant can drip slowly or intermittently from the weep hole for a long time before it really becomes a problem. It burns off, so you smell it but don't see any puddling on the floor. Once you do, it's time to replace the pump.
I've done it twice on my A4 car, at 104k and 175k, but my M6 car at 89k is still rocking the original, though I get the smell occasionally. But it's only driven 5-600 miles a year, so not a concern.
Hopefully this is the end of it because it keeps filling up the expansion tank and it's super annoying. Pump will be here this week.
Hopefully this is the end of it because it keeps filling up the expansion tank and it's super annoying. Pump will be here this week.
That's one symptom I've never had. I can see why you thought it was the cap. One might theorize that the pump isn't working efficiently, the coolant is getting hot and overflowing to the tank. But why doesn't it suck back into the system once it cools overnight? That's a mystery to me.
That's one symptom I've never had. I can see why you thought it was the cap. One might theorize that the pump isn't working efficiently, the coolant is getting hot and overflowing to the tank. But why doesn't it suck back into the system once it cools overnight? That's a mystery to me.
The thing is, is that it doesn't even come close to running hot. I always have the engine temp on my Aeroforce Interceptor. Usually around 195.
I dont think it comes back in because it loses vacuum due to air getting in
Yeah that would suck! I know where my coolant was going though, and its the overflow tank. This was due to thermostat housing leak and water pump weep hole. Won't know for 100% if it's fixed for a few days as my PCM was sent to Frost.
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Coolant issue 
