Losing coolant 95 E320

[Kestas]

During winter storage, I noticed a puddle of coolant develop under the car. Now that I'm getting the car ready, I washed underneath to see where the coolant redevelops and follow the traces. So far, I get coolant drops forming at the bottom of the oil pan, toward the front. I can trace it to the top of the pan, but no further. I've lost almost a gallon of coolant. Is this from my water pump?

[97 SL320]

It could be a water pump but you will need to pressurize the cooling system to be sure.

[Ferdman]

Kestas, use a small mirror to view the water pump weep hole. Chances are the seal is shot and you need a new water pump. Best to buy a rebuilt water pump from a MB dealer. Trade your old one in and avoid paying the core charge. While you're replacing the water pump it's a good time to replace the thermostat.

[Kestas]

I added coolant, and it started leaking again more profusely, and it's coming from the water pump area. Apparently, the coolant leaked out of the water pump until the level dropped to that point where it stopped, which is almost a gallon. I already ordered a Graf water pump.

[timmyr]

About 4-5weeks ago, i began noticing coolant loss. It wasnt a constant leak. In my case, it wouldnt lose coolant while running( @operating temp.) , however, every morning or every other morning i would notice a puddle of coolant underneath the car, and an empty expansion tank.


The following is exactly what i noticed :

Originally Posted by Kestas

During winter storage, I noticed a puddle of coolant develop under the car. ... So far, I get coolant drops forming at the bottom of the oil pan, toward the front. I can trace it to the top of the pan, but no further.

Have replaced the water pump, and since, all has been well.

hope this helps.

good luck

[Kestas]

Thanks for verifying the symptoms. I'm fairly confident the leak is from the water pump. The hose connections seemed tight, and it wasn't leaking from that. I couldn't see the actual weep hole, even with a mirror.

I'm just glad the problem presented itself before the driving season, and before I tucked the winter car away.

[lsmalley]

While you are doing the water pump (which means all coolant will be out of the car) you should also do all the hoses, thermostat, and check the integrity of the coolant temp sensor. Might also be a good time to replace belt and tensioner if you haven't done so.