W124 leaking antifreeze - water pump? - PeachParts Mercedes-Benz Forum

qdessa · #1 06-09-2007, 08:46 PM

All,
I have a 88 300ce that is leaking coolant. There is a steady drip that goes down the drivers side of the oil pan.

All the hoses ,etc look good. I think it is the water pump, but before I dig into that I want to make sure that is the culprit.

The thing that has me stumped is that when I took the hoses of the pump there was still AF in it. If the seal in the pump was shot I would think it would have leaked out.

Where else could it be coming from?

Thanks in advance

Alan

brewtoo · #2 06-09-2007, 10:13 PM

The water pump leaks around the shaft and it runs down and drips off the oil pan.

mbshop · #3 06-10-2007, 05:48 PM

most likely the water pump. but make sure its not
the hose that goes to the head. that sucker leaks
and makes the pump look bad.

george

Ferdman · #4 06-11-2007, 12:25 AM

Alan, use a mirror to see if coolant is coming out the weep hole on the water pump. That's a sure sign that the shaft seal is shot and the water pump needs to be replaced. From what I've read it's best to buy a reconditioned water pump from a MB dealer instead of a new aftermarket water pump.

John Plut · #5 06-24-2007, 10:29 AM

There is an O-ring seal between the water pump and the block that may have gone bad. If the pump itself is not leaking, I would suspect the seal.

I had the same problem you describe,. I spent lots of time under the car trying to pinpoint the lead and it seemed to be coming from behind the mounting bracket.

The bad news is that you have to completely remove the water pump to replace the o-ring. If you're going to go through the trouble of removing the water pump, you might as well put on a new one (unless you have time to spare for that sort of thing).

smharr4 · #6 06-24-2007, 06:44 PM

I had the exact same symptoms, and my problem turned out to be the o-ring that went between the engine block and water pump. You do have to pull the pump to get to the O-ring, so the pump may as well be replaced.

It's a DIY job (albeit lengthy), and can be done from on top of the engine, but the four hex-head bolts holding the pump to the block are tricky to get to. There's little clearance for the ones on top, and the ones on the bottom aren't easy to see from above the engine, and you may end up unfastening the wrong ones.

Be sure to order the correct pump, the Laso one I received (from this site) is missing holes for two sensors on top, I'm going to have to order another one with the additional holes.